Poly-ε-caprolactone based nanoparticles for delivery of genistein in melanoma treatment

Abstract We developed poly-ε-caprolactone (PCL)-based nanoparticles containing D-α-tocopherol polyethylene glycol-1000 succinate (TPGS) or Poloxamer 407 as stabilizers to efficiently encapsulate genistein (GN). Two formulations, referred to as PNTPGS and PNPol, were prepared using nanoprecipitation. They were characterized by size and PDI distribution, zeta potential, nanoparticle tracking analysis (NTA), GN association (AE%), infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). PNTPGS-GN exhibited a particle size of 141.2 nm, a PDI of 0.189, a zeta potential of -32.9 mV, and an AE% of 77.95%. PNPol-GN had a size of 146.3 nm, a better PDI than PNTPGS-GN (0.150), a less negative zeta potential (-21.0 mV), and an AE% of 68.73%. Thermal and spectrometric analyses indicated that no new compounds were formed, and there was no incompatibility detected in the formulations. Cellular studies revealed that Poloxamer 407 conferred less toxicity to PCL nanoparticles. However, the percentage of uptake decreased compared to the use of TPGS, which exhibited almost 80% cellular uptake. This study contributes to the investigation of stabilizers capable of conferring stability to PCL nanoparticles efficiently encapsulating GN. Thus, the PCL nanoparticle proposed here is an innovative nanomedicine for melanoma therapy and represents a strong candidate for specific pre-clinical and in vivo studies.

pH-Responsive polymer boosts cytosolic siRNA release for retinal neovascularization therapy

Small interfering RNA (siRNA) has a promising future in the treatment of ocular diseases due to its high efficiency, specificity, and low toxicity in inhibiting the expression of target genes and proteins. However, due to the unique anatomical structure of the eye and various barriers, delivering nucleic acids to the retina remains a significant challenge. In this study, we rationally design PACD, an A-B-C type non-viral vector copolymer composed of a hydrophilic PEG block (A), a siRNA binding block (B) and a pH-responsive block (C). PACDs can self-assemble into nanosized polymeric micelles that compact siRNAs into polyplexes through simple mixing. By evaluating its pH-responsive activity, gene silencing efficiency in retinal cells, intraocular distribution, and anti-angiogenesis therapy in a mouse model of hypoxia-induced angiogenesis, we demonstrate the efficiency and safety of PACD in delivering siRNA in the retina. We are surprised to discover that, the PACD/siRNA polyplexes exhibit remarkable intracellular endosomal escape efficiency, excellent gene silencing, and inhibit retinal angiogenesis. Our study provides design guidance for developing efficient nonviral ocular nucleic acid delivery systems.

Lipid-polymer hybrid nanoparticle with cell-distinct drug release for treatment of stemness-derived resistant tumor

Drug resistance presents one of the major causes for the failure of cancer chemotherapy. Cancer stem-like cells (CSCs), a population of self-renewal cells with high tumorigenicity and innate chemoresistance, can survive conventional chemotherapy and generate increased resistance. Here, we develop a lipid-polymer hybrid nanoparticle for co-delivery and cell-distinct release of the differentiation-inducing agent, all-trans retinoic acid and the chemotherapeutic drug, doxorubicin to overcome the CSC-associated chemoresistance. The hybrid nanoparticles achieve differential release of the combined drugs in the CSCs and bulk tumor cells by responding to their specific intracellular signal variation. In the hypoxic CSCs, ATRA is released to induce differentiation of the CSCs, and in the differentiating CSCs with decreased chemoresistance, DOX is released upon elevation of reactive oxygen species to cause subsequent cell death. In the bulk tumor cells, the drugs are released synchronously upon the hypoxic and oxidative conditions to exert potent anticancer effect. This cell-distinct drug release enhances the synergistic therapeutic efficacy of ATRA and DOX with different anticancer mechanism. We show that treatment with the hybrid nanoparticle efficiently inhibit the tumor growth and metastasis of the CSC-enriched triple negative breast cancer in the mouse models.

Effects of Platycodonis Radix-Curcumae Rhizoma on oral nanoparticle uptake and in vitro inhibition against breast cancer metastasis / 中国中药杂志

This study combined the herbal pair Platycodonis Radix-Curcumae Rhizoma(PR-CR) possessing an inhibitory effect on tumor cell proliferation and metastasis with the active component of traditional Chinese medicine(TCM) silibinin-loaded nanoparticles(NPs) with a regulatory effect on tumor microenvironment based on the joint effect on tumor cells and tumor microenvironment to inhi-bit cell metastasis. The effects of PR-CR on the cellular uptake of NPs and in vitro inhibition against breast cancer proliferation and metastasis were investigated to provide an experimental basis for improving nanoparticle absorption and enhancing therapeutic effects. Silibinin-loaded lipid-polymer nanoparticles(LPNs) were prepared by the nanoprecipitation method and characterized by transmission electron microscopy. The NPs were spherical or quasi-spherical in shape with obvious core-shell structure. The mean particle size was 107.4 nm, Zeta potential was-27.53 mV. The cellular uptake assay was performed by in vitro Caco-2/E12 coculture cell model and confocal laser scanning microscopy(CLSM), and the results indicated that PR-CR could promote the uptake of NPs. Further, in situ intestinal absorption assay by the CLSM vertical scanning approach showed that PR-CR could promote the absorption of NPs in the enterocytes of mice. The inhibitory effect of NPs on the proliferation and migration of 4T1 cells was analyzed using 4T1 breast cancer cells and co-cultured 4T1/WML2 cells, respectively. The results of the CCK8 assay showed that PR-CR-containing NPs could enhance the inhibition against the proliferation of 4T1 breast cancer cells. The wound healing assay indicated that PR-CR-containing NPs enhanced the inhibition against the migration of 4T1 breast cancer cells. This study enriches the research on oral absorption of TCM NPs and also provides a new idea for utilizing the advantages of TCM to inhibit breast cancer metastasis.

Commentary: polymer binding modules accelerate enzymatic degradation of poly(ethylene terephthalate) / 生物工程学报

The large scale production and indiscriminate use of plastics led to serious environmental pollution. To reduce the negative effects of plastics waste on the environment, an approach of enzymatic degradation was put forward to catalyze plastics degradation. Protein engineering strategies have been applied to improve the plastics degrading enzyme properties such as activity and thermal stability. In addition, polymer binding modules were found to accelerate the enzymatic degradation of plastics. In this article, we introduced a recent work published in Chem Catalysis, which studied the role of binding modules in enzymatic hydrolysis of poly(ethylene terephthalate) (PET) at high-solids loadings. Graham et al. found that binding modules accelerated PET enzymatic degradation at low PET loading (< 10 wt%) and the enhanced degradation cannot be observed at high PET loading (10 wt%-20 wt%). This work is beneficial for the industrial application of polymer binding modules in plastics degradation.

Effect of polymer nanoparticles on atherosclerotic lesions and the associated mechanisms: a review / 生物工程学报

Polymer nanoparticles generally refer to hydrophobic polymers-based nanoparticles, which have been extensively studied in the nanomedicine field due to their good biocompatibility, efficient long-circulation characteristics, and superior metabolic discharge patterns over other nanoparticles. Existing studies have proved that polymer nanoparticles possess unique advantages in the diagnosis and treatment of cardiovascular diseases, and have been transformed from basic researches to clinical applications, especially in the diagnosis and treatment of atherosclerosis (AS). However, the inflammatory reaction induced by polymer nanoparticles would induce the formation of foam cells and autophagy of macrophages. In addition, the variations in the mechanical microenvironment of cardiovascular diseases may cause the enrichment of polymer nanoparticles. These could possibly promote the occurrence and development of AS. Herein, this review summarized the recent application of polymer nanoparticles in the diagnosis and treatment of AS, as well as the relationship between polymer nanoparticles and AS and the associated mechanism, with the aim to facilitate the development of novel nanodrugs for the treatment of AS.

Advances in bioanalysis methods and pharmacokinetics of polymer nanopharmaceuticals / 药学学报

Polymer nanomaterials have been attracted more and more attention because of their advantages such as long circulation, reduced immunogenicity and less side effects, and have become a hot research topic in nanomaterials. However, the number of polymer nanomedicines successfully applied in clinical application is very limited, and the unsatisfactory pharmacokinetic behavior is one of the main reasons for thisresult. After polymer nanoparticles enter the body, they will release free drugs and polymer excipients. Polymer nanoparticles are the loaded drugs and free drugs are the active chemicals for efficacy, while polymer excipients may cause excipient drug interactions. Therefore, the focus of the pharmacokinetics study of polymer nanoparticles should not be only limited to the free drugs themselves, but should also focus on the loaded drugs, free drugs and polymer excipients. The dynamic changes of polymer excipients and their metabolites pose new requirements and challenges for the bioanalysis of polymer nanomedicines. The characteristics and application scope of common analytical methods for detection polymer nanomedicines including chromatographic assay will be discussed in this paper. Moreover, this review will also summarize the absorption, distribution, metabolism and excretion of polymer nanomedicines. We hope this review will provide reference for the pharmacokinetics study, safety and effectiveness evaluation of polymer nanomedicines.

Pharmacokinetics, pharmacodynamics, and tissue distribution of oral co-loaded puerarin/daidzein mixed micelles in rats / 中国中药杂志

This study investigated the drug delivery performance of oral co-loaded puerarin(PUE) and daidzein(DAZ) mixed micelles(PUE/DAZ-FS/PMMs) from the perspectives of pharmacokinetics, pharmacodynamics, and tissue distribution. The changes in PUE plasma concentration in rats were evaluated based on PUE suspension, single drug-loaded micelles(PUE-FS/PMMs), and co-loaded micelles(PUE/DAZ-FS/PMMs). Spontaneously hypertensive rats(SHR) were used to monitor systolic blood pressure, diastolic blood pressure, and mean arterial pressure for 10 weeks after administration by tail volume manometry. The content of PUE in the heart, liver, spleen, lung, kidney, brain, and testes was determined using LC-MS/MS. The results showed that compared with PUE suspension and PUE-FS/PMMs, PUE/DAZ-FS/PMMs significantly increased C_(max) in rats(P<0.01) and had a relative bioavailability of 122%. The C_(max), AUC_(0-t), AUC_(0-∞), t_(1/2), and MRT of PUE/DAZ-FS/PMMs were 1.77, 1.22, 1.22, 1.17, and 1.13 times higher than those of PUE suspension, and 1.76, 1.16, 1.08, 0.84, and 0.78 times higher than those of PUE-FS/PMMs, respectively. Compared with the model control group, PUE/DAZ-FS/PMMs significantly reduced systolic blood pressure, diastolic blood pressure, and mean arterial pressure in SHR rats(P<0.05). The antihypertensive effect of PUE/DAZ-FS/PMMs was greater than that of PUE suspension, and even greater than that of PUE-FS/PMMs at high doses. Additionally, the distribution of PMMs in various tissues showed dose dependency. The distribution of PMMs in the kidney and liver, which are metabolically related tissues, was lower than that in the suspension group, while the distribution in the brain was higher than that in the conventional dose group. In conclusion, PUE/DAZ-FS/PMMs not only improved the bioavailability of PUE and synergistically enhanced its therapeutic effect but also prolonged the elimination of the drug to some extent. Furthermore, the micelles facilitated drug penetration through the blood-brain barrier. This study provides a foundation for the development of co-loaded mixed micelles containing homologous components.

mRNA delivery in cancer immunotherapy

Messenger RNA (mRNA) has drawn much attention in the medical field. Through various treatment approaches including protein replacement therapies, gene editing, and cell engineering, mRNA is becoming a potential therapeutic strategy for cancers. However, delivery of mRNA into targeted organs and cells can be challenging due to the unstable nature of its naked form and the low cellular uptake. Therefore, in addition to mRNA modification, efforts have been devoted to developing nanoparticles for mRNA delivery. In this review, we introduce four categories of nanoparticle platform systems: lipid, polymer, lipid-polymer hybrid, and protein/peptide-mediated nanoparticles, together with their roles in facilitating mRNA-based cancer immunotherapies. We also highlight promising treatment regimens and their clinical translation.

Orally Disintegrating Film: A Review of Its Formulation and Manufacturing Method

@#Oral route drug delivery system is still considered as the most convenient and patient friendly drug delivery route. Over the decades, many research has been performed to improve the functionality oral dosage form. Orally disintegrating film (ODF) is a newer oral drug delivery system, which is in the form of a thin film that will disintegrate in the oral cavity within a matter of seconds. The aim of this review paper is to recap ODF, its benefits, formulation contents and manufacturing method. With more research and development work has been conducted on ODF, the dosage form is expected to be manufactured and scaled up to be commercializable products to be sold in the market.

Optimization and verification of size exclusion chromatography-high performance liquid chromatography for determination of recombinant human growth hormone-Fc immunofusion protein polymer / 中国生物制品学杂志

@#Objective To optimize and verify the size exclusion chromatography-high performance liquid chromatography(SEC-HPLC) method for the determination of recombinant human growth hormone(rhGH)-Fc immunofusion protein polymer.Methods The multimer content of rhGH-Fc immunofusion protein was detected by SEC-HPLC.The detection conditions(salt concentration,mobile phase pH,flow rate,column temperature and column model) were optimized to observe the separation effect of the target proteins and polymers.The system suitability,specificity,linearity and range,precision,accuracy and limit of quantification of the method were verified.Results The optimized method was to use TSK-gel G2000SW_(x1)column(5 μm,7.8 mm × 300 mm),mobile phase of 50 mmol/L phosphate buffer(pH 6.80),detection wavelength of280 nm,injection volume of 100 μL,flow rate of 0.6 mL/min and column temperature of 45 ℃.The resolution of rhGHFc immunofusion protein and polymer,the theoretical plate number and the tailing factor all met the requirements;the peak time of rhGH-Fc immunofusion protein was the same as that of the control,while the peak time of GH national standard was different from that of the control,and the protein buffer showed no peak;the concentration of rhGH-Fc immunofusion protein was in the range of 0.307～1.842 mg/mL with good linear correlation between the peak area integral value and the injection volume(R~2=0.999 4);the RSD of peak area and purity in repeatability verification were 0.7% and 0.1%,respectively;the RSD of intermediate precision verification was 0.8%;the average recovery rate of accuracy verification was 99.1% with the RSD of 1.9%;the limit of quantification was 6 μg/mL.Conclusion The optimized SEC-HPLC method was used to detect the content of polymer in rhGH-Fc immunofusion protein with improved accuracy,and the column efficiency and separation were in accordance with the relevant requirements of Chinese Pharmacopoeia(Volume Ⅳ,2020edition),which could be used for the detection of polymer content in samples.

Application status and prospect of biodegradable polymer stents in pancreatobiliary disease / 中华肝胆外科杂志

Endoscopic stent implantation is one of the main methods for the treatment of biliary and pancreatic diseases. At present, the commonly used biliary and pancreatic stents are mainly plastic and metal stents which are still have some deficiencies in clinical applications, and the emergence of the new type of biodegradable polymer materials is expected to achieve the purpose of treatment to overcome these shortcomings. It is a potential hope to break through the bottleneck of endoscopic treatment of choleopancreatic diseases. Previous animal experiments and human clinical studies have preliminarily shown its safety and effectiveness, which can effectively solve some problems of bile and pancreatic duct stenosis and so on. Biodegradable polymer stents have been widely studied, but their clinical application progress is slow and not yet popular, and it has gradually become a research hotspot in recent years . This article discusses the research status and development direction of biodegradable polymer stents in biliary and pancreatic diseases.

Influential factors of hypoalbuminemia in patients with preeclampsia and observation of pregnancy outcomes / 中国基层医药

Objective:To analyze the influential factors of hypoalbuminemia in patients with preeclampsia and observe the pregnancy outcomes.Methods:The clinical data of 237 pregnant women with preeclampsia who received treatment in The Sixth Affiliated Hospital of Guangzhou Medical University (Qingyuan People's Hospital) from July 2018 to December 2020 were retrospectively collected and analyzed. These patients were divided into hypoproteinemia (observation group) and no hypoproteinemia (control group) groups according to whether they had hypoproteinemia. The general situation, clinical data, and adverse maternal and infant outcomes were statistically analyzed. Risk factors of hypoalbuminemia were analyzed using a logistic regression model. The predictive efficacy was evaluated using the receiver operating characteristic curve.Results:There were no significant differences in general data between the two groups (all P > 0.05). Multivariate analysis showed that D-dimer ( OR = 1.25, P = 0.004), 24-hour urinary protein ( OR = 1.29, P < 0.001), and total bile acid ( OR = 1.08, P = 0.010) were the independent risk factors for hypoproteinemia in preeclampsia. The predictive efficacy of these three indicators (area under the receiver operating characteristic curve = 0.855, P < 0.001) was greater than that of a single indicator. The incidences of adverse maternal and infant outcomes including placental abruption (9.4%, P = 0.019), liver and kidney dysfunction (34.4%, P < 0.001), pleural and ascitic fluid (28.1%, P = 0.001), fetal intrauterine growth restriction (50.0%, P = 0.001), fundus lesions (6.2%, P = 0.018), HELLP syndrome (9.4%, P = 0.019), mild neonatal asphyxia (15.6%, P = 0.022), severe asphyxia (6.2%, P = 0.049), metabolic acidosis (12.5%, P = 0.001), intrauterine infection (12.5%, P = 0.004), and neonatal hospitalization for more than 20 days (37.5%, P < 0.001) were greater in the observation group compared with the control group. There were no significant differences in postpartum hemorrhage, eclampsia, respiratory distress syndrome, fetal loss, and neonatal death between the two groups (all P > 0.05). Conclusion:D-dimer, 24-hour urinary protein, and total bile acid are independent risk factors for hypoproteinemia in preeclampsia. Patients with preeclampsia complicated by hypoproteinemia have a high risk of adverse maternal and infant outcomes.

Application value of the aortic dissection detection risk score plus D-dimer for the early diagnosis of acute aortic dissection / 中国基层医药

Objective:To investigate the application value of aortic dissection detection risk score (ADD-RS) combined with D-dimer (DD) in the early diagnosis of acute aortic dissection (AAD).Methods:The clinical data of 70 patients with suspected aortic dissection detection admitted to The Second Hospital of Jiaxing from August 2019 to April 2020 were collected. All patients were scored using the ADD-RS, and grouped according to the scoring results. The sensitivity and specificity of ADD-RS plus DD in the early diagnosis of AAD were calculated. The areas under the receiver operating characteristic (ROC) curves that were plotted for drADD-RS plus DD versus DD alone to screen AAD were compared to evaluate efficacy. Results:CT angiography results showed that among 70 patients with suspected AAD, 29 patients had AAD and 41 patients had no AAD. A total of 21 patients were scored 0, 41 patients were scored > 1, and 8 patients were scored > 0. ADD-RS > 0 had an overall sensitivity of 79.31% and a specificity of 36.59% for AAD diagnosis. DD test results had an overall sensitivity of 86.20% and a specificity of 36.50% for AAD diagnosis. The area under the ROC curve of ADD-RS = 0 plus DD-negative result and the area under the ROC curve of DD-negative result alone in ruling out AAD were 0.885 with 95% CI (0.786-0.949) and 0.787 with 95% CI (0.673-0.876), respectively. The difference between the two groups was statistically significant ( P = 0.024). Conclusion:Compared with DD-negative result alone, the ADD-RS = 0 plus DD-negative result strategy offers greater specificity to rule out AAD. The combined strategy has a greater efficacy in ruling out AAD. However, a multi-center study involving a large sample is required for in-depth evaluation.

Application progress in synthetic and natural polymer materials for dural membrane repair / 国际生物医学工程杂志

The dura mater is a double-layer tough membrane tissue located between the surface of the brain and the inner surface of the skull that supports and protects the brain tissue. The phenomenon of dural defects caused by tumor resection, inflammation destruction, and craniotomies is becoming more common clinically. Therefore, the development of effective dural repair materials can not only reduce the leakage of cerebrospinal fluid and the occurrence of epilepsy complications but also promote the recovery of the dural defect to its normal physiological structure. With the continuous development of modern medicine, many biomaterials have been developed for dural defect repair. At present, the most promising and most researched biomaterials are synthetic polymer materials and natural polymer materials. Synthetic polymer materials have been extensively studied by domestic and foreign scholars due to their stable performance, low foreign body infection, and easy mass production advantages. Natural polymer materials are the most promising biomaterials because of their extensive sources, excellent biocompatibility, and biodegradability advantages. This article summarizes the research progress based on synthetic polymer materials and natural polymer materials in dural repair materials. In this review paper, the application progress of synthetic polymer materials and natural polymer materials in dural membrane repair was reviewed.

A novel biodegradable polymer scaffold for in vitro growth of corneal epithelial cells

The shortage of donor corneal tissue worldwide has led to extensive research for alternate corneal equivalents utilizing tissue engineering methods. We conducted experiments using Poly D, L lactic acid polymer along with a copolymer (Eudragit) in varying concentrations to create a biodegradable scaffold suitable for in vitro growth of corneal epithelial stem cells. It was found that stable, spherical, and porous microparticles can be prepared by combining PDLLA and Eudragit RL100 polymers in the ratio of 90:10 and 70:30. The microparticles can then be fused to form scaffold membranes with porous architecture and good water retention capacity at room temperature using methanol, which can withstand handling during transplantation procedures. The scaffolds made using a 70:30 ratio were found to be suitable for the promotion of growth of laboratory corneal epithelial stem cell lines (SIRC cell lines). This innovation can pave way for further developments in corneal stem cell research and growth, thus providing for viable laboratory-derived corneal substitutes.

In Vitro effect of denture cleansers on the color stability of polyetheretherketone and other denture base polymers / Efecto in vitro de los limpiadores de prótesis en la estabilidad del color de la polieteretercetona y otros polímeros base de prótesis

Abstract The aim of this in vitro study was to compare the long-term effect of overnight use of denture cleansers with different chemical compositions on the color stability of denture base polymers (DBPs). The four DBPs evaluated were PEEK (PK group), thermoinjection-molded polyamide (PA group), auto-polymerized polymethylmethacrylate (PMMA) (AP group), and heat-polymerized resin PMMA (HP group). The cleaning agents used were Corega tablet (CT), Protefix tablet (PT), and 0.5% sodium hypochlorite (NaOCl) solution (SH). Distilled water (DW) served as a control. Forty-eight disc-shaped specimens (10mm × 2mm) were prepared from each DBP and randomly immersed in the different storage media (n=12 in each group). Color measurements of the specimens before and after immersion in the denture cleansers were made using a spectrophotometer (VITA Easyshade V). The color changes were measured and recorded in L* a* b*. After 120 d, the CIEDE2000 formula was used to calculate color changes (ΔE00). For analysis of the data, a multivariate analysis of variance was used (p<0.05). The results of the statistical analysis revealed significant color change differences in the DBPs immersed in the various denture cleansers (p<0.05). Groups PA and PK showed the highest values for all solutions. AP-SH showed the highest ΔE00 value in group AP, no significant difference was found between other solutions. In group HP, there was no statistically significant difference between the average ΔE00 values of all solutions. Long-term daily use of the denture cleansers affected the color stability of all the DBPs, although the level of color change was acceptable. Laboratory and clinical studies on the color stability of PEEK are needed to confirm the results of this study.

Resumen El objetivo de este estudio in vitro fue comparar el efecto a largo plazo del uso nocturno de limpiadores de prótesis con diferentes composiciones químicas sobre la estabilidad del color de los polímeros base de prótesis (DBP). Los cuatro DBP evaluados fueron PEEK (grupo PK), poliamida moldeada por termoinyección (grupo PA), polimetilmetacrilato (PMMA) autopolimerizado (grupo AP) y resina PMMA termopolimerizada (grupo HP). Los agentes de limpieza utilizados fueron Corega (CT), Protefix (PT) y la solución de hipoclorito de sodio (NaOCl) al 0,5% (SH). El agua destilada (DW) sirvió de control. Se prepararon 48 especímenes en forma de disco (10mm × 2mm) de cada DBP y se sumergieron al azar en los diferentes medios de almacenamiento (n=12 en cada grupo). Las mediciones del color de las muestras antes y después de la inmersión en los limpiadores de dentaduras se realizaron con un espectrofotómetro (VITA Easyshade V). Los cambios de color se midieron y registraron en L* a* b*. Después de 120 d, se utilizó la fórmula CIEDE2000 para calcular los cambios de color (ΔE00). Para el análisis de los datos, se utilizó un análisis multivariante de la varianza (p<0,05). Los resultados del análisis estadístico revelaron diferencias significativas en el cambio de color de los DBP sumergidos en los distintos limpiadores de dentaduras (p<0,05). Los grupos PA y PK mostraron los valores más altos para todas las soluciones. AP-SH mostró el valor ΔE00 más alto en el grupo AP, no se encontraron diferencias significativas entre las demás soluciones. En el grupo HP, no hubo diferencias estadísticamente significativas entre los valores medios de ΔE00 de todas las soluciones. El uso diario a largo plazo de los limpiadores de dentaduras afectó a la estabilidad del color de todos los DBP, aunque el nivel de cambio de color fue aceptable. Se necesitan estudios de laboratorio y clínicos sobre la estabilidad del color del PEEK para confirmar los resultados de este estudio.

Curcumin solid dispersion based on three model acrylic polymers: formulation and release properties

Abstract To investigate structure-property relationship of polymer-based curcumin solid dispersion (SD), three acrylic polymers were used to formulate curcumin SD by solvent evaporation method. Curcumin Eudragit EPO SD (cur@EPO), curcumin Eudragit RS PO SD (cur@RSPO) and curcumin Eudragit RL PO SD (cur@RLPO) showed deep red, golden orange and reddish orange color, respectively. Cur@RSPO entrapped 15.42 wt% of curcumin followed by cur@RL PO and cur@EPO. FTIR spectra indicated that in cur@EPO, curcumin may transfer hydrogen to the dimethylaminoethyl methacrylate group and thus change its color to red. In contrast, curcumin may form hydrogen bonding with Eudragit RS PO and Eudragit RL. Curcumin exists in amorphous state in three SDs as proved by differential scanning calorimetry and X-Ray diffraction measurement. In vitro digestion presented that lower pH value in simulated gastric fluid (SGF) stimulates the curcumin release from cur@EPO while permeability influences the release profile in other two SDs. When in simulated intestinal fluid (SIF), first order release model governs the release behaviors of all three SDs which showed sustained release pattern. Our results are helpful to elucidate how structure of polymer may impact on the major properties of curcumin contained SD and will be promising to broaden its therapeutic applications.

Giomer technology for preventive and restorative clinical management of erosive tooth wear: a case report / Tecnologia Giomer para manejo clínico preventivo e restaurador de desgaste dentário erosive: relato de caso

Increasing prevalence of erosive tooth wear (ETW) is notable mainly due to current knowledge and its early diagnosis. Once teeth are functionally and/or esthetically affected, dental restorations may become necessary. Materials capable of interacting with the eroded dental tissue allied to their resistance to subsequent continuous erosive challenges are desirable. Giomer technology based on S-PRG (surface pre-reactive glass) filler has been launching to provide benefits for the dental treatment due to its innovative multi-ionic release system, which involves fluoride. This case report describes the employment of preventive and restorative materials based on this technology for a patient under frequent erosive challenges and complaining about dental sensitivity. Patient reported immediate reduction on this sensitivity and the restorations has been followed up for 2 years, presenting satisfactory performance. S-PRG-based systems seem to be promissory for preventive and therapeutic management of ETW used simultaneously with the patient compliance. (AU)

O aumento da prevalência do desgaste dentário erosivo (DDE) é notável especialmente devido ao conhecimento atual e seu diagnóstico precoce. Uma vez que os dentes são afetados funcional e/ou esteticamente, restaurações dentárias se tornam necessárias. Materiais focados na habilidade de interagir com o tecido dentário erodido associados com sua resistência aos desafios erosivos contínuos subsequentes são desejáveis. A tecnologia Giomer baseada em partículas S-PRG (superfície de vidro pré-reativo) foi lançada no mercado para oferecer benefícios para o tratamento odontológico devido ao seu sistema inovador de liberação multi-iônica, que envolve o flúor. Esse caso clínico descreve o uso de materiais preventivo e restaurador baseados nessa tecnologia em um paciente em desafio erosivo e com queixa de sensibilidade. O paciente relatou redução imediata da sensibilidade e as restaurações foram acompanhadas por 2 anos apresentando desempenho satisfatório. Sistemas baseados em S-PRG se mostram promissores para manejo preventivo e terapêutico do DDE empregados simultaneamente à colaboração do paciente.(AU)

Effects of polyvinylpyrrolidone and poly (ethylene glycol) on preparation of ibuprofen pharmaceutical cocrystal

Abstract In this study, we investigated the effects of polymers on the pharmaceutical cocrystal formation process. Ibuprofen (IBU) was selected as the active pharmaceutical ingredient (API), nicotinamide (NIC) and saccharin (SAC) as the cocrystal coformer (CCF), ethanol/water as the solvent, polyvinylpyrrolidone (PVP) and poly (ethylene glycol) (PEG) as the representative polymers. We prepared IBU-NIC and IBU-SAC cocrystals in ethanol-water cosolvent in the absence or presence of polymers. Cocrystal screening products were characterized by FTIR, DSC, PXRD, and HPLC. The results showed that the mixture of IBU and IBU-NIC cocrystal can be prepared in ethanol-water cosolvent without polymers. The addition of PVP facilitates the formation of pure IBU-NIC cocrystal; however, no cocrystal was formed in PEG solutions. SAC could not cocrystallize with IBU in the ethanol-water solvent in the absence of polymers. Neither PVP nor PEG could facilitate the formation of the IBU-SAC cocrystal.