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This study evaluated the effects of ultrasonic activation (US) associated to glycolic acid (GA) on smear layer, dentin structure and bond strength (BS) of filling/restorative material to root dentin. The roots were used for antimicrobial activity, dentin structure and BS evaluation, being distributed into seven groups, according to irrigation protocols: G1:DW+US; G2:17% EDTA; G3:QMix; G4:17% GA; G5:17% EDTA+US; G6:QMix+US; G7:17% GA+US. Scanning electronic microscopy, transmission electronic microscopy and push-out were performed, with specific statistical analysis for each evaluation. The highest smear layer removal occured in Groups 6 and 7 (p<0.05), and the largest collagen dispersion in Group 7, being similar to Group 2 and 5 (p>0.05). The highest BS of filling and restorative material occurred in Groups 6 and 7, and Groups 5, 6 and 7, respectively, being similars between them (p>0.05). The use of GA+US promoted effective smear layer removal and dentin structure preservation, improving the BS of filling/restorative material to root dentin.
Subject(s)
Acids , Edetic Acid , EndodonticsABSTRACT
We constructed and optimized the plasmid DNA (pDNA) Opt-S encoding the gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, using poly (lactic-co-glycolic acid) copolymer (PLGA) as a delivery carrier for pDNA. PLGA-pDNA NPs were loaded by nanoprecipitation and its properties in vitro were preliminary evaluated. The results showed that the prepared PLGA-pDNA NPs were regular morphology, clear edges, with an average particle size of (184.2 ± 2.4) nm, polydisperse index (PDI) of 0.093 ± 0.013, zeta potential of (-68.10 ± 0.36) mV, and encapsulation rate of (98.92 ± 0.22)%. The PLGA-pDNA NPs were stable at -20 ℃ for 7 months and could protect pDNA against nuclease degradation. And they also exhibited sustained release of pDNA in vitro. The PLGA-pDNA NPs have low cytotoxicity and high safety. In addition, in vitro transfection experiments showed that the SARS-CoV-2 S gene could enter cells and be expressed. These results indicate that PLGA-pDNA NPs non-viral gene vector have simple preparation process and good performance, which are expected to provide a new idea for the research and development of SARS-CoV-2 vaccine.
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Polylactic-co-glycolic acid (PLGA) has the characteristics of biocompatibility, biodegradability, modifiability, and slow release, which has attracted extensive attention in the treatment of gynecological diseases. This paper summarizes the relevant literature reports at home and abroad in recent years, expounds the research situation of PLGA nanoparticles as drug carriers in gynecological diseases such as ovarian cancer, breast cancer, cervical cancer and endometriosis, and looks forward to its great potential in clinical application in gynecological diseases, providing guidance for its prevention and treatment in gynecological diseases.
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Existe uma associação entre diabetes e a periodontite, e a Metformina (MET) além de controlar os níveis glicêmicos, tem apresentado efeitos antiinflamatórios e na diminuição da perda óssea periodontal. Ao se veicular a MET a um sistema de nanopartículas pode-se apresentar a vantagem de aumento da eficácia terapêutica. Objetivos: esse estudo consistiu na avaliação dos efeitos antiinflamatórios, perda óssea e disponibilidade in vitro/in vivo de uma nanopartícula de ácido poli lático-co-glicólico (PLGA) associada à MET em um modelo de periodontite induzida por ligadura. Materiais e métodos: o PLGA carreado com diferentes doses da MET foi caracterizado pelo seu diâmetro médio, tamanho da partícula, índice de polidispensão e eficiência de aprisionamento. Foram utilizados ratos machos da linhagem Wistar, divididos aleatoriamente, em grupos controles e experimentais com diferentes doses de MET associadas ou não ao PLGA, os quais receberam diferentes tratamentos. Amostras de maxilas e tecidos gengivais foram utilizadas para avaliação de perda óssea e inflamação, por meio da microtomografia computadorizada, histopatológico, imunohistoquímica, análise de citocinas inflamatórias e expressão gênica de proteínas por RT-PCR quantitativo. Para o ensaio de liberação in vitro, utilizou-se o dispositivo de células de difusão vertical de Franz estáticas. Para a disponibilidade in vivo, as amostras de sangue foram coletadas em diferentes intervalos de tempo e analisadas por cromatografia líquida de alta eficiência acoplado a espectrometria de massas (HPLC-MS/MS). Resultados: o diâmetro médio das nanopartículas de PLGA carreadas com MET estava em um intervalo de 457,1 ± 48,9 nm (p <0,05) com um índice de polidispersidade de 0,285 (p <0,05), potencial Z de 8,16 ± 1,1 mV (p <0,01) e eficiência de aprisionamento (EE) de 66,7 ± 3,73. O tratamento com a MET 10 mg / kg + PLGA mostrou uma baixa concentração de células inflamatórias, fraca imunomarcação para RANKL, Catepsina K, OPG e osteocalcina. Diminuição dos níveis de IL-1ß e TNF-α (p <0,05), aumento da expressão gênica do AMPK (p <0,05) e diminuição do NF-κB p65, HMGB1 e TAK-1 (p <0,05). O 10 mg/kg MET + PLGA foi liberado no ensaio in vitro sugerindo um modelo cinético de difusão parabólica com um perfil de liberação que atinge 50% de seu conteúdo em 2h e permanece em liberação constante em torno de 60% até o final de 6h. O ensaio in vivo mostrou o volume aparente de distribuição Vz/F (10 mg/kg MET + PLGA, 46,31 mL/kg vs. 100 mg/kg MET + PLGA, 28,8 mL/kg) e o tempo médio de residência MRTinf (PLGA + MET 10 mg /kg, 37,66h vs. MET 100 mg/kg, 3,34h). Conclusão: o PLGA carreado com MET diminuiu a inflamação e a perda óssea na periodontite em ratos diabéticos. O 10 mg/kg MET + PLGA teve uma taxa de eliminação mais lenta em comparação com o MET 100 mg/kg. A formulação modifica os parâmetros farmacocinéticos, como volume de distribuição aparente e tempo médio de residência (AU).
There is an association between diabetes and periodontitis, and Metformin (MET) in addition to controlling glycemic levels, has shown anti-inflammatory effects and decreased periodontal bone loss. By transferring MET to a nanoparticle system, the advantage of increasing therapeutic efficacy can be presented. Objectives: this study consisted of evaluating the antiinflammatory effects, bone loss and in vitro/in vivo availability of a polylactic-co-glycolic acid (PLGA) nanoparticle associated with MET in a ligature-induced periodontitis model. Materials and methods: PLGA loaded with different doses of MET was characterized by its mean diameter, particle size, polydispension index and entrapment efficiency. Male Wistar rats were used, randomly divided into control and experimental groups with different doses of MET associated or not with PLGA, which received different treatments. Samples of jaws and gingival tissues were used to assess bone loss and inflammation, using computed microtomography, histopathology, immunohistochemistry, analysis of inflammatory cytokines and gene expression of proteins by quantitative RT-PCR. For the in vitro release assay, the static Franz vertical diffusion cell device was used. For in vivo availability, blood samples were collected at different time intervals and analyzed by high performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Results: the mean diameter of MET-loaded PLGA nanoparticles was in the range of 457.1 ± 48.9 nm (p <0.05) with a polydispersity index of 0.285 (p <0.05), Z potential of 8.16 ± 1.1 mV (p <0.01) and trapping efficiency (EE) of 66.7 ± 3.73. Treatment with MET 10 mg/kg + PLGA showed a low concentration of inflammatory cells, weak immunostaining for RANKL, Cathepsin K, OPG and osteocalcin. Decreased IL-1ß and TNF-α levels (p <0.05), increased AMPK gene expression (p <0.05) and decreased NF-κB p65, HMGB1 and TAK-1 (p <0. 05). The 10 mg/kg MET + PLGA was released in the in vitro assay suggesting a kinetic model of parabolic diffusion with a release profile that reaches 50% of its content in 2h and remains in constant release around 60% until the end of 6h . The in vivo assay showed the apparent volume of distribution Vz/F (10 mg/kg MET + PLGA, 46.31 mL/kg vs. 100 mg/kg MET + PLGA, 28.8 mL/kg) and the mean MRTinf residency (PLGA + MET 10 mg/kg, 37.66h vs. MET 100 mg/kg, 3.34h). Conclusion: MET-loaded PLGA decreased inflammation and bone loss in periodontitis in diabetic rats. 10 mg/kg MET + PLGA had a slower rate of elimination compared to 100 mg/kg MET. The formulation modifies pharmacokinetic parameters such as apparent volume of distribution and mean residence time (AU).
Subject(s)
Animals , Rats , Periodontal Diseases/therapy , Polylactic Acid-Polyglycolic Acid Copolymer/adverse effects , Metformin/adverse effects , In Vitro Techniques/methods , Biological Availability , Analysis of Variance , Rats, Wistar , Hypoglycemic Agents/adverse effects , Anti-Inflammatory Agents/adverse effectsABSTRACT
In order to meet the clinical needs of long-acting sustained-release thienorphine, injectable thienorphine loaded microspheres were developed, and the accelerated stability study was carried out to explore the suitable storage and transportation conditions of the microspheres. Using poly(lactic-co-glycolic acid) (PLGA) as carrier material, 3 batches of microspheres were prepared in pilot scale with emulsion solvent evaporation method. By investigating the in vitro release of thienorphine loaded microspheres at 37, 45, 52, and 60 ℃, and applying the Arrhenius equation, the linear relationship between the release rate constant (lgk) and the temperature (1/T) was established to obtain the equation: lgk = -8.073/T + 24.35 (R2 = 0.985 3), which showed that the release of microspheres at high temperature can be used to predict the release in vitro at 37 ℃, and 52.0 ± 0.5 ℃ was selected as the accelerated release condition in vitro. The quality research methods were established to investigate the changes of critical quality attributes such as microsphere morphology, drug loading, particle size and distribution, polymer molecular weight, and the related substances under accelerated conditions. The difference factor f1 and similarity factor f2 were used to assess the similarity of release behavior under accelerated conditions. The results showed that under the accelerated experimental conditions of 25 ± 2 ℃ and relative humidity (RH) 60% ± 5%, the critical quality attributes of injectable thienorphine loaded microspheres had no significant change in 6 months, suggesting that the long-term storage condition could be 5 ± 3 ℃.
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Objective:To observe the efficacy of drug combined with red-blue light irradiation, chemical peeling by glycolic acid and intense pulsed light (IPL) in the treatment of moderate acne vulgaris.Methods:A total of 187 patients with moderate acne vulgaris were divided into five groups. There were 59 males and 128 females, aged from 16 to 29 years (21.79±2.52). In group A, patients were treated with oral medicines; the patients were treated with oral medicines combined with red-blue light irradiation, chemical peeling by glycolic acid and IPL respectively in group B, group C and group D. In group E, patients were treated with oral medicines combined with chemical peeling by glycolic acid and IPL. The number of different types of skin lesions (comedoes, papules, pustules) were compared between before and after treatment in five groups. The clinical effect of five treatment groups was evaluated by comparing regression rates of different types of skin lesions and total skin lesions and treatment efficiency.Results:All the patients with moderate acne vulgaris were brought into this study. The regression rates of comedoes, papules and total skin lesions were (86.37±9.64)%, (94.25±9.79)% and (88.80±9.40)% respectively in group E, and significantly higher than that of other four groups ( P<0.05). The treatment efficiency of group E also were significantly higher than that of other four groups ( P<0.05). Then, the regression rates of comedoes (70.91±18.52) in group C was significantly higher than that of group A and group B ( P<0.05). The regression rates of papules (91.42±13.86) in group D was significantly higher than that of group A and group B ( P<0.05). Conclusions:Oral medicines combined with chemical peeling by glycolic acid and IPL has obvious clinical efficacy in treatment of patients with moderate acne vulgaris. Oral medicines combined with chemical peeling by glycolic acid can obviously improve comedoes, and oral medicines combined with IPL can obviously improve papules.
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Objective:To develop a novel sustained-release local anesthetic microspheres and evaluate the effects on sciatic nerve block in rabbits.Methods:The magnetic lidocaine microspheres were prepared by W 1/O/W 2 compound emulsion method, investigating their external morphology, measuring the magnetic response characteristics by the VSM and draw the hysteresis loop.The encapsulation efficiency and drug-loading rate were calculated, and the cumulative release curves in vitro were drawn.Fifteen healthy rabbits (half male and half female), aged 5-6 months, weighing 3.0-3.5 kg, were selected for sciatic nerve block and divided into 3 groups ( n=5 each) using a random number table method: magnetic response lidocaine microspheres group (PL group), normal saline control group (C group) and lidocaine group (L group). Magnetic response lidocaine microsphere buffer 2 ml, normal saline 2 ml and 2% lidocaine 2 ml were injected around the rabbit sciatic nerve through a catheter in PL, C and L groups, respectively.The applied magnetic field was withdrawn at 60 h after injection.Before injection (T 0) and at 30 min and 2 , 8, 16, 24, 48, 60, 62 and 64 h after injection (T 1-9), the compound action potentials and conduction velocities of bilateral sciatic nerve trunks were measured, and block was assessed using toe reflex score and modified Tarlov score. Results:The magnetic lidocaine microspheres were brown in color and observed as monodisperse, regular spheres with a diameter of (9±3) μm, an encapsulation rate of 46.18%, a drug loading of 6.02%, and a superparamagnetic release rate of 97% in vitro at 60 h. The hysteresis loop passed through the origin and no hysteresis occurred with the absence of an external magnetic field.Compared with C group, the action potentials and conduction velocities of the sciatic nerve, toe reflex score and modified Tarlov score were significantly decreased at T 1-T 8 in PL group ( P<0.05). Compared with L group, the action potentials and conduction velocities of the sciatic nerve were significantly increased at T 1, the action potential was decreased at T 2-T 8, the conduction velocity was decreased at T 3-T 8, the toe reflex score was increased at T 1 and decreased at T 3-T 8, and the modified Tarlov score was increased at T 1 and T 2 and decreased at T 3-T 8 in PL group ( P<0.05). Conclusions:Magnetic response lidocaine microsphere is successfully developed with good magnetic responsiveness and release and can prolong the sciatic nerve block time in rabbits.
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Objective:To evaluate the physicochemical properties, degradation and drug release behaviour, cytocompatibility and bacteriostatic properties in vitro of porous magnesium alloy scaffolds containing vancomycin/poly(lactic-co-glycolic acid) (PLGA). Methods:Porous magnesium scaffolds (Mg-2Zn-0.3Ca) were prepared using the template replication technique. The MgF 2 surface layer was obtained by high temperature fluorination. The vancomycin/PLGA porous magnesium alloy drug-loaded scaffolds were obtained by homogeneous lifting after submersion in a dichloromethane solution of PLGA containing vancomycin hydrochloride. According to the products at each stage of the preparation (scaffolds of magnesium alloy, magnesium fluoride alloy, PLGA coated magnesium fluoride alloy, and vancomycin/PLGA magnesium fluoride alloy), they were divided into an Mg group, an MgF 2 group, a PLGA group, and a vancomycin/PLGA group. Immediately after preparation, the material science characterization, degradation rate, drug release rate, antibacterial properties, hemocompatibility, and cell proliferation and differentiation ability of the scaffolds were measured and evaluated. Results:Vancomycin-loaded magnesium alloy scaffolds were successfully prepared with an average porosity of 66.39%. Their degradation rate [(0.540±0.102) mm/year] was significantly lower than that of the Mg ones [(10.048±0.297) mm/year] ( P<0.05). Their pH of degradation in Hank equilibrium salt solution was close to the physiological pH. Their release of vancomycin was fast in the first 48 h and gradually slowed down after 48 h. Their cumulative drug concentration reached a maximum of 43 mg/L at d 11; their vancomycin was still released slowly after d 11. The antimicrobial rate in the vancomycin/PLGA group (97.89%±0.28%) was significantly higher than that in the Mg group (74.92%±2.20%), the MgF 2 group (78.46%±2.59%) and the PLGA group (61.08%±4.21%) ( P<0.05). Their hemolysis rate (0.55%) was much lower than the requirement of ISO 10993-4 (5%). The extract liquid from them promoted the proliferation of rat bone marrow mesenchymal stem cells (BMSCs), showing a gradually increased proliferation rate from d1 (104.80%±5.13%) to d3 (112.36%±2.07%) and d7 (127.79%±4.61%). The calcium nodules in BMSCs were significantly increased at d 14, with an OD value of absorbance of 1.189±0.020, significantly higher than that in the Mg group (0.803±0.020), the MgF 2 group (0.878±0.028) and the PLGA group (0.887±0.026) ( P<0.05). Conclusion:Vancomycin/PLGA-loaded porous magnesium alloy scaffolds exhibit good material properties, antibacterial properties, biocompatibility and osteogenic properties in vitro.
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ABSTRACT@#Various grafting materials are utilised to facilitate regeneration. There is currently a paradigm shift towards applying poly lactic-co-glycolic acid (PLGA), which is regarded as an excellent scaffold for tissue engineering. Concentrated growth factor (CGF) has also been reported to promote wound healing. Nevertheless, the role of PLGA microspheres as a substitute for bone graft material with CGF in bone regeneration remains unclear. This study was designed to evaluate the effect of CGF with PLGA on bone formation and the expression of alkaline phosphatase (ALP) following socket preservation. PLGA microspheres were prepared using double solvent evaporation method and observed under scanning electron microscopy (SEM). A 6 mL of rabbit’s blood was collected from the marginal ear vein and centrifuged to obtain CGF. Blood was also collected for ALP assessment from 24 New Zealand White (NZW) male rabbits subjected to the first upper left premolar extraction. Sockets were filled with CGF, PLGA, CGF+PLGA or left empty and observed with microscopic computed tomography (micro-CT) at four weeks and eight weeks. The SEM image revealed a spherical shape with interconnected pores on the surface of the PLGA particles. Repeated measures ANOVA were used to evaluate the effect of time and treatment (p < 0.05) with significant differences in bone width, height, volume, volume fraction and expression of ALP was observed with CGF+PLGA. Both CGF and PLGA have the potential as the alternative grafting materials and this study could serve as an ideal benchmark for future investigations on the role of CGF+PLGA in bone regeneration enhancement.
Subject(s)
Bone Regeneration , Platelet-Derived Growth Factor , Polylactic Acid-Polyglycolic Acid CopolymerABSTRACT
RESUMO Introdução: O ácido glicólico é aplicado para o tratamento estético e dermatológico em formulações antirrugas (anti-aging), esfoliantes químicos (peeling). Considerando a grande utilização em produtos cosméticos, é de suma importância a realização do controle de qualidade dos produtos cosméticos contendo ácido glicólico, com a finalidade de garantir maior segurança para os usuários. Objetivo: Avaliar a qualidade de produtos cosméticos de venda livre contendo ácido glicólico disponíveis no comércio nacional. Materiais e métodos: Foram avaliadas 8 amostras de produtos cosméticos contendo ácido glicólico. Os testes realizados foram: análise do rótulo, características organolépticas dos produtos, determinação do pH, teste de centrifuga e doseamento do ácido glicólico. Quanto ao teor de ácido glicólico as 8 amostras foram aprovadas, pois permaneceram dentro do limite máximo estabelecido pela Anvisa de 10% de ácido glicólico. Resultados: No que se refere à avaliação do pH, 4 amostras apresentaram valores abaixo permitido, sendo que o uso de produtos com pH abaixo de 3,5 pode causar irritação e lesão da pele. Já na análise do rótulo as amostras manipuladas faltavam às recomendações e precauções de uso. Conclusão: Dessa forma, fica evidente a importância do controle de qualidade em produtos contendo ácido glicólico para conferir segurança e eficácia para os usuários.
SUMMARY Introduction: Glycolic acid is applied for the aesthetic and dermatological treatment in anti-aging formulations, chemical exfoliators (peeling). Considering the great use of glycolic acid in cosmetic products and their applicability, it is become important to carry out the quality control of cosmetic products containing glycolic acid, in order to guarantee its quality as well safety to users. Aim: To evaluate the quality of glycolic acid in cosmetic over the counter available in the national market. Materials and methods: 8 samples of cosmetic products containing glycolic acid were evaluated. The following tests were performed: label analysis, organoleptic characteristics of the products, pH determination, centrifuge test and glycolic acid assay (volumetric analysis). Regarding the glycolic acid content, the 8 samples were approved, as they remained within the maximum limit established by Anvisa of 10% glycolic acid. Results: Regarding the pH evaluation, 4 samples presented values below the allowed, being that the use of products with pH below 3.5 may cause irritation and damage skin. Already in the analysis of the labels from compounding formulation samples, there was no recommendations and precautions of use. Conclusion: This way, the importance of quality control in glycolic acid containing products is evident to provide safety and efficacy to users.
RESUMEN Introducción: El ácido glicólico se aplica para el tratamiento estético y dermatológico en formulaciones antiarrugas (antienvejecimiento), exfoliantes químicos (peeling). Es de suma importancia realizar el control de calidad de los productos cosméticos que contienen ácido glicólico, teniendo en cuenta su amplio uso en productos cosméticos, para garantizar una mayor seguridad para los usuarios. Objetivo: Evaluar la calidad de los productos cosméticos de venta libre que contienen ácido glicólico disponibles en el mercado nacional. Materiales y métodos: Se evaluaron 8 muestras de productos cosméticos que contenían ácido glicólico. Las pruebas realizadas fueron: análisis de etiquetas, características organolépticas de los productos, determinación de pH, prueba de centrifugación y ensayo de ácido glicólico. En cuanto al contenido de ácido glicólico, las 8 muestras fueron aprobadas, ya que se mantuvieron dentro del límite máximo establecido por Anvisa para el ácido glicólico al 10%. Resultados: En cuanto a la valoración del pH, 4 muestras arrojaron valores inferiores a los permitidos y el uso de productos con un pH inferior a 3,5 puede provocar irritación y daño cutáneo. En el análisis de la etiqueta, las muestras manipuladas carecieron de las recomendaciones y precauciones de uso. Conclusión: De esta forma, se evidencia la importancia del control de calidad en los productos que contienen ácido glicólico para garantizar la seguridad y efectividad para los usuarios.
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@#To prepare a minocycline hydrochloride microsphere depot and evaluate its release performance and physicochemical properties, poly (lactic-co-glycolic acid) (PLGA) was used as raw material, the minocycline hydrochloride microspheres were prepared by electrospray, and the morphology and size distribution of the microspheres were characterized by polarizing microscopy and scanning electron microscopy (SEM). The microspheres were then mixed with sucrose acetate isobutyrate (SAIB) depot at a ratio of 1:10 to form a minocycline hydrochloride microsphere depot, and its release performance and porosity changes were evaluated. The results showed that the microspheres had smooth surface and the diameter was (5.294 ± 1.222) μm. After the microspheres were added into SAIB depot, the burst release of minocycline hydrochloride significantly decreased from 60% to 3.27% at the first day, and then the release lasted for 42 days . Additionally, the porosity of the depot increased rapidly from (12.53 ± 0.43)% to (32.53 ± 0.43)% during days 0-15, and increased slowly from (32.53 ± 0.43)% to (33.81 ± 0.54)% during days 15-45. The minocycline hydrochloride microsphere depot prepared in this study is expected to be an effective way for the application of minocycline hydrochloride for its good release performance and simple preparation process.
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Objective:To study the clinical effect of alpha hydroxy acids on facial acne patients.Methods:A total of 36 patients with facial acne who were treated at the Department of Dermatology, Beijing Friendship Hospital from December 1, 2018 to May 31, 2019 were selected. All patients were treated with 20% alpha hydroxy acids. Treatment efficiency, lesions improvement and patients＇satisfaction were evaluated.Results:All evaluation indexes were improved after treatment. Before treatment, patients with acne were classified into grade Ⅰ(9 cases), grade Ⅱ(18 cases ), and grade Ⅲ (9 cases) through Pillsbury Grading, and after treatment, there were 28 cases of grade Ⅰ, 28 cases of grade Ⅱ, and 0 cases of grade Ⅲ, which had statistic differences ( χ2= 22.603, P<0.001). The number of lesions before treatment was 38.64±15.57, and that was 16.17±11.49 after treatment, and the difference was statistically significant ( t=6.967, P<0.001). After treatment, 2 cases were cured, 17 cases were markedly effective, 11 cases were effective, 2 cases were ineffective and 4 cases were worsening. 30 patients were cured, markedly effective or effective, and the total effective rate was 83.33%. The value of skin pores before treatment was 1263.67±593.44, and decreased to 1196.33±579.27 after treatment. The difference was statistically significant ( t=3.155, P<0.05). After the treatment, all the patients were satisfied with the effect. Conclusions:Alpha hydroxy acid is a safe and effective method for acne patients.
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@#The development of materials science is of great significance to the treatment of dental pulp diseases. Poly lactic acid glycolic acid (PLGA) copolymer is an organic macromolecule compound that is widely used in the preparation of biomedical materials. In recent years, PLGA, as a drug/molecular loaded system and tissue regeneration scaffold, has shown prospects for application in the treatment of dental pulp diseases. This paper will review the application of PLGA in the treatment of dental pulp diseases and provide a basis for its further development and utilization. The results of the literature review show that PLGA is a drug/molecular delivery system that is mainly used in the improvement of pulp capping materials, root canal disinfectant and apexification materials. PLGA-improved pulp capping agents can prolong the action time of the drug and reduce toxicity. The modified root canal disinfectant can realize the sustained release of drug, make the drug penetrate deeper into the subtle structure, and contact more widely with the pathogenic bacteria. The modified apexification materials can provide more convenient administration methods for apexifixment. As a scaffold for tissue engineering, PLGA is mainly used in the study of pulp regeneration. The optimization of PLGA physical properties and action environment can provide a more suitable microenvironment for seed cells to proliferate and differentiate. How to utilize the advantages of PLGA to develop a more suitable material for endodontic application needs further study.
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Background: Developing the natural medicine that allow for the specific targeting cytotoxicity is a very important research area in the development of anti-tumor drugs. Aims and Objectives: This study was conducted to determine the targeted inhibitory effects of luteolin-loaded Her-2-poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) on gastric cancer cells and to delineate the mechanism underlying the inhibition of tumors by luteolin. Materials and Methods: Luteolin-loaded Her-2-PLGA NPs (Her-2-NPs) were prepared, physically and chemically characterized, and their effects on gastric cancer cells were investigated. The rate of NP uptake by cells and the cell morphology were observed using confocal microscopy; the rates of cell proliferation and apoptosis were identified using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay and flow cytometry, respectively; and the mRNA and protein expression levels of forkhead box protein O1 (FOXO1) were determined using quantitative polymerase chain reaction and Western blotting, respectively. Results: Compared with nontargeted microspheres, Her-2-NPs led to significantly enhanced uptake of luteolin by SGC-7901 cells. Luteolin-loaded Her-2-NPs also significantly inhibited the proliferation of gastric cancer cells, weakened their migratory ability, and increased both the mRNA and protein expression levels of FOXO1. Conclusion: Luteolin-loading of Her-2-NPs could potentially be used as a novel anti-cancer drugs for targeted cancer therapy.
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To prepare the mimetic exosomes and co-delivery proteins and nucleic acids, and achieve efficient and safe co-delivery of multi-component drugs, an optimized formulation was designed by modifying a polylactic acid-glycolic acid copolymer (PLGA) matrix with a cationic lipid excipient dioleyl trimethylammonium propane (DOTAP), and a PLGA/DOTAP nanoparticles packaged protein and nucleic acid was prepared by double emulsion method, and the outermost membrane structure prepared by reverse phase evaporation method and consists of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol and membrane proteins. The structure of the mimetic exosomes is formed by ultrasonic dispersion and extrusion, and analyzed its characteristics and nature of the transfer effect. The size of mimetic exosomes was about 156.13 nm, with negative charge (-18.23 ± 0.57 mV), and it could efficiently co-transfer protein and siRNA, and siRNA could effectively inhibit the expression of target gene Trim28. The mimetic exosomes simulate the structure of exosomes and achieve safe and efficient co-delivery of multi-component drugs.
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@#Introduction: : Ginseng is a type of traditional medicine that has been used for thousand years to treat various diseases and has been proven effective in treating cardiovascular diseases. Incorporation of polyaniline (PANI) which is a type of conductive polymer together with ginseng into poly(lactic-co-glycolic acid) (PLGA) microcapsules is necessary for the treatment of cardiovascular diseases as the polymer will control drug release and the electroconductivity of PANI is beneficial on myocardium cells. Methods: Therefore, this project involved the encapsulation of ginseng inside PLGA/PANI microcapsules. The encapsulation of ginseng inside the microcapsules was verified through the identification of chemical composition of ginseng, PLGA and PANI using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). Results: The results of scanning electron microscope (SEM) showed the formation of microspheres where the microcapsule size was decreased from 3.14±1.87 μm to 1.98±1.30 μm as the concentration of PANI increased. The distribution of microcapsules size was more homogeneous in the high concentration of PANI as been determined through the histogram analysis. In addition, the fluorescence analysis demonstrated the efficiency of ginseng encapsulation inside PLGA/PANI microcapsules through the appearance of stained ginseng inside the microcapsules. Conclusion: As a conclusion, the ginseng was successfully encapsulated within PLGA/PANI microcapsules that will be beneficial in drug delivery application, specifically in the cardiovascular area.
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BACKGROUND: Anti-tuberculous chemotherapy is the main method for treating bone and joint tuberculosis. However, systemic administration hardly maintains the effective drug concentration in the focus area, and the therapeutic efficacy is unsatisfactory. OBJECTIVE: To prepare a chitosan-gelatin/poly(lactic-co-glycolic acid) combined with drug-loaded hydrogel, which can release anti-tuberculosis drugs in situ for a long time and promote osteogenesis. METHODS: Isoniazid, a hydrophilic anti-tuberculosis drug, and a hydrophobic stromal cell derived factor-1 were loaded into poly(lactic-co-glycolic acid) by double emulsion method to prepare drug-loaded poly(lactic acid co-glycolic acid) microspheres, which were then mixed into chitosan gelatin/poly(lactic acid co-glycolic acid) combined with drug-loaded hydrogel. The ability of drug delivery and anti-tuberculosis of poly(lactic acid co-glycolic acid) microspheres and chitosan gelatin/poly(lactic acid co-glycolic acid) combined with drug-loaded hydrogels in vitro were tested. MC3T3-E1 cells were inoculated on the surface of microspheres and hydrogel respectively. The biocompatibility was detected by cell counting kit-8 assay. The osteogenetic activity was detected by alkaline phosphatase activity. RESULTS AND CONCLUSION: (1) The burst release of isoniazid in the microspheres was about 23.3% in 1 hour, 42.6% in 2 days, and then it entered the sustained-release stage in the later 25 days. The burst release of stromal cell derived factor was about 19.8% in 1 hour, 44.7% in 2 days, and then it entered the sustained-release stage in the next 25 days. The release of isoniazid and stromal cell-derived factor in the combined drug-loaded hydrogel was 8.3% and 8.5% in the first hour, respectively. The cumulative release rates on the second day were 15.2% and 17.6%, respectively, which were much lower than that of poly(lactic acid co-glycolic acid) microspheres. (2) After 4 weeks in vitro, the antibacterial diameter of the combined drug-loaded hydrogel was much larger than that of the drug-loaded microspheres, and the antibacterial rate was higher than that of the drug-loaded microspheres (P < 0.05). (3) The combined drug-loaded hydrogel and the drug-loaded microspheres had good cytocompatibility and cell viability was about 100%. (4) After 5 and 10 days of culture, there was no significant difference in the activity of alkaline phosphatase on the surface of drug-loaded hydrogel and drug-loaded microspheres. (5) These results show that the in situ chitosan-gelatin/poly(lactic acid co-glycolic acid) combined with drug-loaded hydrogel can be used for treating tuberculosis and other bone and joint infections.
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BACKGROUND: Bone tissue engineering has provided a novel ideal for treating bone defects in clinic. This study is the first to combine traditional Chinese medicine with the nanostructures of tissue-engineered scaffolds in order to explore and construct a new bone tissue substitute material for the treatment of bone defects. OBJECTIVE: To investigate the osteogenic activity of icariin (ICA)/hydroxyapatite (HA)/poly(lactic-co-glycolic acid) (PLGA) composite scaffolds. METHODS: A HA/PLGA composite scaffold was prepared by physical blending of HA and PLGA, and was then soaked in ICA solution of different concentrations to obtain the HA/ICA/PLGA scaffold. Rabbit bone marrow mesenchymal stem cells were used to evaluate the cell adhesion, proliferation, osteogenesis and cytotoxicity of the composite scaffold. The cell adhesion, proliferation and cytotoxicity were detected by MTT method. The activities of alkaline phosphatase and osteocalcin were detected by ELISA. The expression levels of osteogenic genes and proteins were detected by fluorescence quantitative PCR and western blot assay, respectively. RESULTS AND CONCLUSION: Adding appropriate amount of HA into PLGA could improve the mechanical strength of the scaffold, and 10% HA had the best effect with tensile strength of (1.67±0.37) MPa, and compression modulus of (4.17±1.62) MPa, and nanostructure would be formed on the surface of the scaffold. The nanostructure could promote the adhesion of bone marrow mesenchymal stem cells on the surface of the scaffold. ICA did not affect the proliferation of bone marrow mesenchymal stem cells on the composite scaffold. However, the HA/PLGA composite scaffold soaked in 1.00 µmol/L ICA aqueous solution had the optimal osteogenic differentiation function, and the expression levels of alkaline phosphatase, osteocalcin, osteogenic related genes and proteins (Runx-2 and COL I) were increased. The ICA/HA/PLGA scaffold had no cytotoxicity. These results suggest that HA (10%)/ICA (1.00 µmol/L)/PLGA scaffold has good mechanical properties, osteogenesis and biocompatibility, which has the potential to be a favorable scaffold for bone tissue engineering.
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BACKGROUND: Transforming growth factor Β3/polylactic acid-glycolic acid (TGF-Β3/PLGA) sustained-release microspheres can maintain the effective drug concentration at the site of action and provide the feasibility for efficient utilization of growth factors. OBJECTIVE: To optimize the manufacturing process of TGF-Β3/PLGA sustained-release microspheres, and investigate their effects on the proliferation and migration of rabbit adipose-derived mesenchymal stem cells (ADSCs). METHODS: TGF-Β3/PLGA sustained-release microspheres were prepared by emulsification-solvent evaporation method. The morphology, particle size, drug spatial distribution, encapsulation efficiency, drug loading, and sustained release properties of the microspheres were characterized. The TGF-Β3/PLGA sustained-release microspheres were dissolved in phosphate buffered saline. The concentration of TGF-Β3 in the supernatant was detected at the corresponding time points. The microsphere morphology was observed by scanning electron microscopy at the corresponding time point. Adipose-derived mesenchymal stem cells were divided into six groups and then cultured with single culture medium (negative control) or culture medium containing TGF-Β3 or blank PLGA, or culture medium containing 10,100,1 000 g/L TGF-Β3/PLGA microspheres. Cell proliferation was detected by CCK-8 assay at the corresponding time point. Cells in each group were cultured for 24 hours with corresponding medium in a non-contact manner. The number of migratory cells was counted. RESULTS AND CONCLUSION: (1) TGF-Β3/PLGA sustained-release microspheres were spherical with smooth surface, no adhesion, and evenly distributed particle size. The microspheres had a diameter of 2-50 µm, and the protein drugs in the microspheres were evenly distributed, with high encapsulation efficacy and encapsulation dose. (2) The TGF-Β3/PLGA sustained-release microspheres had good degradation properties and were completely degraded after 6 months in vitro. At the same time, these microspheres had good sustained-release performance and released TGF-Β3 slowly for 45 days in vitro. (3) Blank microspheres and the sustained-release microspheres containing TGF-Β3 had no effect on the proliferation of adipose-derived mesenchymal stem cells. (4) Blank microspheres had no effect on the migration of adipose-derived mesenchymal stem cells, and the transforming growth factor 3 and the sustained-release microspheres containing TGF-Β3 promoted the migration of adipose-derived mesenchymal stem cells. There was no significant difference in the migration promotion between different concentrations of TGF-Β3. (5) These findings suggest that the TGF-Β3/PLGA sustained-release microspheres can promote the migration of adipose-derived mesenchymal stem cells without affecting their proliferation.
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Objective: The aim of the study to develop surface modified targeted moiety α-tocopherol (α-t) encapsulated with 5-fluorouracil (5-FU)-poly-D, L-lactic-co-glycolic acid nanoparticles (PLGA NPs) toward the anticancer activity against oral squamous cell carcinoma (OSCC). Materials and Methods: 5-FU was conjugated with the polymer, PLGA by ionic cross-linking and α-tocopherol use as a functionalized surface moiety. Characterization, drug entrapment efficiency, and in-vitro drug release system were optimized at different pH 7.4 and pH 4.5. The in-vitro cell was performed to optimize the anticancer activity through MTT assay and apoptotic staining assay was also performed by flow cytometry to evaluate the cellular apoptotic activity and cellular uptake. Results: The particle size was distributed within an average range of 145–162 nm, the polydispersity index values lie 0.16–0.30, and the surface charge was at the negative side, –17mV to –23mV. The in vitro drug release system showed more sympathetic situation at pH 7.4 as compared to pH 4.5, for targeted NPs, approximately 86% and 69%, respectively. The non-targeted 5-FU-PLGA NPs showed drug release of 83% and 64% at pH 7.4 and 4.5 subsequently. In vitro anticancer activity confirmed the intense inhibition by α-t-FU-PLGA NPs of 79.98% after 96 h treatment of SCC15 cells and confirmed the steady-state inhibition of 83.74% after 160 h incubation in comparison to 5-FU-PLGA NPs. Subsequently, the early apoptosis, 27.98%, and 16.45%, and late apoptosis, 47.29%, and 32.57%, suggested the higher apoptosis rate in targeted NPs against OSCC. Conclusions: The surface modified α-t-FU-PLGA NP was treated over SCC15 cells, and the oral cancer cells have shown the high intensity of cellular uptake, which confirmed that the target moiety has successfully invaded over the surface of cancer cells and shown advanced targeted delivery against OSCC