Predatory bacterial hydrogels for topical treatment of infected wounds

Wound infection is becoming a considerable healthcare crisis due to the abuse of antibiotics and the substantial production of multidrug-resistant bacteria. Seawater immersion wounds usually become a mortal trouble because of the infection of Vibrio vulnificus. Bdellovibrio bacteriovorus, one kind of natural predatory bacteria, is recognized as a promising biological therapy against intractable bacteria. Here, we prepared a B. bacteriovorus-loaded polyvinyl alcohol/alginate hydrogel for the topical treatment of the seawater immersion wounds infected by V. vulnificus. The B. bacteriovorus-loaded hydrogel (BG) owned highly microporous structures with the mean pore size of 90 μm, improving the rapid release of B. bacteriovorus from BG when contacting the aqueous surroundings. BG showed high biosafety with no L929 cell toxicity or hemolysis. More importantly, BG exhibited excellent in vitro anti-V. vulnificus effect. The highly effective infected wound treatment effect of BG was evaluated on mouse models, revealing significant reduction of local V. vulnificus, accelerated wound contraction, and alleviated inflammation. Besides the high bacterial inhibition of BG, BG remarkably reduced inflammatory response, promoted collagen deposition, neovascularization and re-epithelization, contributing to wound healing. BG is a promising topical biological formulation against infected wounds.

Immobilization of mutated xylanase from Neocallimastix patriciarum in E. coli and application for kraft pulp biobleaching / Imobilização de xilanase mutada de Neocallimastix patriciarum em E. coli e aplicação para polpa kraft

Abstract As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.

Resumo Como importante enzima, a xilanase é amplamente utilizada na indústria alimentícia, de celulose e têxtil. Diferentes aplicações de xilanase garantem condições específicas, incluindo temperatura e pH. Este estudo teve como objetivo realizar grânulos de alginato de sódio como carreador para imobilizar xilanase mutada relatada anteriormente de Neocallimastix patriciarum que expressa em E. coli, a atividade de imobilização da xilanase mutada foi elevada em cerca de 4% em pH 6 e 13% a 62 °C. Além disso, a xilanase mutada imobilizada reteve uma proporção maior de sua atividade do que o tipo amplo em termoestabilidade. Essas propriedades sugerem que a imobilização da xilanase mutada tem potencial para aplicação na indústria de biobranqueamento.

Preparation and preliminary evaluation of sodium alginate/agarose/carboxymethyl chitosan spray film dressing carrying platelet rich plasma for wound repair / 中国输血杂志

【Objective】 To develop a spray-on membrane dressing for wound repair containing platelet rich plasma (PRP) sodium alginate (SA)/agarose(AG)/carboxymethyl chitosan (CMCS). 【Methods】 SA/AG/ CMCS were mixed in different proportions to prepare biodegradable quick setting spray (BQSS) by blending film method, and the film-forming time, moisture retention and compression resistance of the prepared BQSS were tested. Then PRP and BQSS were mixed in the proportion of 3∶7, 4∶6, 5∶5, 6∶4 and 7∶3 to prepare PRP-BQSS spray film dressings. The film-forming time, moisture retention, compressive strength, porosity and slow-release effect of growth factors of PRP-BQSS spray film dressings were studied. 【Results】 In the preparation of BQSS compound spray film solution, when SA, AG, CMCS and sterile distilled water were 0.6∶0.6∶0.6∶98.2g, the film-forming time (7.73±0.31) s, moisture retention (75. 54±3.03) % and compression resistance (791.00±68.02) g of the spray-film dressing were the best. The basic properties of PRP-BQSS spray-on film dressings and the release of growth factors show that PRP-BQSS spray-on film dressings can exist in different forms, and with the decrease of PRP concentration percentage, its film-forming time, moisturizing performance and compressive strength showed an upward trend. When the PRP content is 30%, the porosity of the dressing is the highest, about(84.34±0.90)%. The release of platelet-derived growth factor-AA(PDGF-AA), platelet factor-4(PF-4) and transforming growth factor beta (TGF-β) was in a slow upward trend, and the release of the three growth factors was higher than that of PRP group in 48 hours. 【Conclusion】 The preparation method of PRP-BQSS spray film dressing designed in this study is simple and mild, and can form a film quickly, with good biological properties and better growth factor inhibition and sustained-release effect.

Immobilization of mutated xylanase from Neocallimastix patriciarum in E coli and application for kraft pulp biobleaching / Imobilização de xilanase mutada de Neocallimastix patriciarum em E coli e aplicação para polpa kraft

As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.

Como importante enzima, a xilanase é amplamente utilizada na indústria alimentícia, de celulose e têxtil. Diferentes aplicações de xilanase garantem condições específicas, incluindo temperatura e pH. Este estudo teve como objetivo realizar grânulos de alginato de sódio como carreador para imobilizar xilanase mutada relatada anteriormente de Neocallimastix patriciarum que expressa em E. coli, a atividade de imobilização da xilanase mutada foi elevada em cerca de 4% em pH 6 e 13% a 62 °C. Além disso, a xilanase mutada imobilizada reteve uma proporção maior de sua atividade do que o tipo amplo em termoestabilidade. Essas propriedades sugerem que a imobilização da xilanase mutada tem potencial para aplicação na indústria de biobranqueamento.

Immobilization of mutated xylanase from Neocallimastix patriciarum in E. coli and application for kraft pulp biobleaching

Abstract As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.

Resumo Como importante enzima, a xilanase é amplamente utilizada na indústria alimentícia, de celulose e têxtil. Diferentes aplicações de xilanase garantem condições específicas, incluindo temperatura e pH. Este estudo teve como objetivo realizar grânulos de alginato de sódio como carreador para imobilizar xilanase mutada relatada anteriormente de Neocallimastix patriciarum que expressa em E. coli, a atividade de imobilização da xilanase mutada foi elevada em cerca de 4% em pH 6 e 13% a 62 °C. Além disso, a xilanase mutada imobilizada reteve uma proporção maior de sua atividade do que o tipo amplo em termoestabilidade. Essas propriedades sugerem que a imobilização da xilanase mutada tem potencial para aplicação na indústria de biobranqueamento.

Sodium alginate coating simultaneously increases the biosafety and immunotherapeutic activity of the cationic mRNA nanovaccine

The extraordinary advantages associated with mRNA vaccines, including their high efficiency, relatively low severity of side effects, and ease of manufacture, have enabled them to be a promising immunotherapy approach against various infectious diseases and cancers. Nevertheless, most mRNA delivery carriers have many disadvantages, such as high toxicity, poor biocompatibility, and low efficiency in vivo, which have hindered the widespread use of mRNA vaccines. To further characterize and solve these problems and develop a new type of safe and efficient mRNA delivery carrier, a negatively charged SA@DOTAP-mRNA nanovaccine was prepared in this study by coating DOTAP-mRNA with the natural anionic polymer sodium alginate (SA). Intriguingly, the transfection efficiency of SA@DOTAP-mRNA was significantly higher than that of DOTAP-mRNA, which was not due to the increase in cellular uptake but was associated with changes in the endocytosis pathway and the strong lysosome escape ability of SA@DOTAP-mRNA. In addition, we found that SA significantly increased the expression of LUC-mRNA in mice and achieved certain spleen targeting. Finally, we confirmed that SA@DOTAP-mRNA had a stronger antigen-presenting ability in E. G7-OVA tumor-bearing mice, dramatically inducing the proliferation of OVA-specific CLTs and ameliorating the antitumor effect. Therefore, we firmly believe that the coating strategy applied to cationic liposome/mRNA complexes is of potential research value in the field of mRNA delivery and has promising clinical application prospects.

Preparation and Performance of Three-Dimensional Silk FibroinScaffolds with Different Matrix Stiffness / 医用生物力学

Objective After hydrogen bonding between collagen ( COL) and silk fibroin ( SF ) at different concentrations, a composite scaffold with adjustable stiffness was prepared by combining with gel system, and its physical and chemical properties were characterized. Methods SF with different qualities was dissolved in sodium alginate (SA) solution, then COL solution at different concentration and calcium carbonate ( CaCO3 ) powder were added. The hydrogels of SC1, SC2, and SC3 groups were obtained by taking out the mixed solution and adding some gluconic acid lactone ( GDL) powder, and different SF scaffolds were obtained after freeze drying. Results The SF scaffolds with adjustable stiffness were successfully prepared. The compression moduli of SC1, SC2, and SC3 groups were (17. 31±2. 73), (24. 12±1. 81), (32. 54±1. 81) kPa, respectively. The innerstructure of the scaffolds was observed. From SC1 group to SC3 group, pores of the scaffolds were smaller and fewer, and hydrophilicity of the materials become better and better. Conclusions Three-dimensional ( 3D) porous scaffolds with different matrix stiffness can be prepared by changing the concentration of SF and COL solution. The concentration of SF and COL is proportional to the compression modulus, water absorption, water retention and swelling rate of SF scaffolds, while inversely proportional to porosity. The findings of this study are expected to provide theoretical guidance for construction of scaffolds with appropriate matrix stiffness for inducing osteogenic differentiation of mesenchymal stem cells

Preparation and in vitro evaluation of Vancomycin loaded Montmorillonite-Sodium Alginate topical gel for wound infection

Abstract Despite decades of research, wound healing remains a significant public health problem. This study aimed to develop and evaluate a topical sodium alginate gel containing vancomycin (Van) loaded MMT NPs for wound healing applications. Van was loaded in MMT at different conditions (pHs of 6, 7 and temperatures of 40, 50 °C) (Van/MMT NPs). The optimum formulation (with the smallest particle size and a high value of zeta potential; 270.8 ± 77.35 nm and -35.96 ± 2.73, respectively) showed a high drug-loading capacity (entrapment efficacy of 96%) and a sustained release pattern of Van (95%) over 480 min. The optimum Van/MMT NPs were embedded into the sodium alginate (SA) gel (Van/MMT NPs/SA gel). The Van/ MMT NPs/SA gel showed a sustained and slow release pattern of Van (95%) over 50 h. FTIR tests revealed the electrostatic interaction between MMT and Van. The broth macrodilution tube method was used to determine the minimum inhibitory concentration (MIC) of Van, Van/ MMT NPs, and Van/MMT NPs/SA gel against Staphylococcus aureus. The results showed the promising antibacterial activity of Van/MMT NPs/SA gel, thus, this gel can be a promising formulation for the management of infected wounds

Potential Alendronate Sodium drug carrier by preparation and characterization of sodium alginate cross-linked Montmorillonite

Abstract In drug therapy, it is important to provide therapeutic levels of drug to the site of action and maintain them during the treatment. This work describes the in vitro release of alendronate from sodium alginate cross-linked Montmorillonite (MMT) composite beads. Effect of crosslinking cation, concentration of montmorillonite and media on encapsulation efficiencies, and release profiles of alendronate were studied. Beads were characterized using equilibrium swelling ability study, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Energy-dispersive x-ray spectroscopy (EDX) and scanning electron microscopy (SEM). Results indicate that addition of montmorillonite increases the encapsulation efficiencies and slows down the release rates significantly.

Curcumin encapsulated dual cross linked sodium alginate/montmorillonite polymeric composite beads for controlled drug delivery / 药物分析学报

The aim of the present work is fabrication of dual cross linked sodium alginate(SA)/montmorillonite(MMT)microbeads as a potential drug vehicle for extended release of curcumin(CUR).The microbeads were prepared using in situ ion-exchange followed by simple ionotropic gelation technique.The developed beads were characterized by Fourier transform infrared spectroscopy(FTIR),differential scanning calorimetry(DSC),thermogravimetric analysis(TGA),X-ray diffraction(X-RD)and scanning electron microscopy(SEM).The effect of MMT on encapsulation efficiency of CUR and intercalation ki-netics was investigated.Dynamic swelling study and in vitro release study were investigated in simu-lated intestinal fluid(pH 7.4)and simulated gastric fluid(pH 1.2)at 37℃.Results suggested that both the swelling and in vitro release studies were influenced by the pH of test media,which might be suitable for intestinal drug delivery.The release mechanism was analyzed by fitting the release data into Korsmeyer-Peppas equation.

Sodium alginate-guar gum and carbopol based methotrexate loaded mucoadhesive microparticles for colon delivery: An in vitro evaluation

Methotrexate (MTX) is famous for its therapeutic potential against different cancers including colorectal cancer. Goal of the present investigation was to formulate MTX loaded mucoadhesive microparticles for colon targeting. The optimized formulation (MTX-MS2) was composed of mucoadhesive polymers (sodium alginate, guar gum and carbopol 940) in an appropriate ratio. MTXMS2 was developed by ionic-gelation method. The suitable particle size and zeta potential were found to be 21.10 ± 0.18 µm and 3.01 ± 0.16 mV for MTX-MS2 respectively. The % yield (98.60 ± 2.12), % entrapment efficiency (97.98 ± 1.22) and % drug loading (1.04 ± 0.03) were estimated for MTXMS2. The swelling index (0.99 ± 0.04 θ) and mucoadhesion (97.29 ± 4.61%) were significantly (***P ˂ 0.01) achieved with MTX-MS2 as compared to other formulations. The optimum drug release (96.07 ± 4.52%) was significantly achieved with MTX-MS2 at simulated gastric fluid (pH 7.4) for 36 h in a sustained manner. This profile may be attributed towards excellent mucoadhesivness of the polymers used in the formulation. Therefore, the current investigation suggests that mucoadhesive carrier system could be promising approach for colon delivery. Thus, the proposed work would be helpful for the treatment of colorectal canc

Evaluación de la estabilidad de cápsulas de jugo de naranja obtenidas mediante gelificación iónica / Evaluation of the stability of orange juice capsules obtained by ionic gelation

Resumen El método de gelificación iónica, como técnica de encapsulación, se basa en las interacciones entre hidrocoloides, las cuales previenen la posibilidad de daño de compuestos bioactivos presentes en alimentos, tales como los jugos de cítricos. El objetivo del presente estudio fue evaluar la estabilidad de las cápsulas de jugo de naranja, obtenidas mediante gelificación iónica, utilizando pectina y alginato de sodio como agentes encapsulantes. Se determinaron la pérdida de peso, atributos de color, diámetro, morfología macroscópica y densidad en cápsulas elaboradas. Se utilizó un diseño factorial, modificando la concentración de pectina de alto metoxilo (1.5 %, 2 % y 2.5 % p/v), pH (2.5, 3.5 y 4.5) y sólidos solubles totales (SST) a 5 ºBrix y 15 ºBrix, manteniendo constante la concentración de alginato de sodio al 0.5 % (p/v), y se almacenaron a temperatura ambiente (26 ºC) y refrigeración (4 ºC) durante 12 d. Las cápsulas presentaron principalmente forma esférica (> 45 %). Los atributos de color permanecieron estables durante 12 d de almacenamiento. Los SST iniciales y el pH influyeron en la estabilidad de las cápsulas. A una concentración de 15 ºBrix y pH 2.5 no se pudieron formar de manera adecuada las cápsulas, presentando mayor sinéresis y morfologías amorfas. Las cápsulas de jugo de naranja con concentración de pectina 2 % (p/v), alginato de sodio 0.5 % (p/v), SST 5 ºBrix y pH 2.5, se mantuvieron estables con parámetros de calidad apropiados al ser almacenadas a temperatura de refrigeración (4 ºC). El método de gelificación iónica mediante encapsulación ofrece una alternativa para prolongar la vida útil del jugo, y el desarrollo de nuevos productos elaborados a partir de este cítrico.

Abstract The ionic gelation method as an encapsulation technique is based on the interactions between hydrocolloids, which prevent the possibility of damage of bioactive compounds present in foods, such as citrus juice. Therefore, the objective of the present study was to evaluate the stability of the orange juice capsules obtained by ionic gelation using pectin and sodium alginate as encapsulating agents. The effects of the gelling agents on the stability were determined by the measurement of weight loss, diameter, color attributes, diameter, macroscopic morphology, density in elaborate capsules. In addition, a factor analysis design was used by modifying the concentration of high methoxyl pectin (1.5 %, 2 % and 2.5 % w/v), pH (2.5, 3.5 and 4.5) and total soluble solids (TSS) at 5 ºBrix and 15 ºBrix, maintaining the concentration of sodium alginate constant at 0.5 % (w/v). The capsules were stored at room temperature (26 ºC) and refrigeration (4 ºC) for 12 d. They mainly presented a spherical shape (> 45 %). The color attributes remained stable even after 12 d of storage. The initial TSS and pH influenced the stability of the capsules. At a concentration of 15 ºBrix and pH 2.5, the capsules could not be adequately formed, capsules presenting greater syneresis and amorphous morphologies. However, the orange juice capsules remained stable for more than 2 weeks and with stable quality parameters when stored at refrigeration temperature (4 ºC), pectin concentration 2 % (w/v), sodium alginate 0.5 % (w/v), TTS 15 ºBrix and pH 2.5. The ionic gelation method through encapsulation offers an alternative to extend the shelf life of the juice and the development of new products made from this citrus.

Preparation and characterization of sodium methacrylate modified photocrosslinked alginate hydrogel scaffold / 中国组织工程研究

BACKGROUND: Photocrosslinked alginate hydrogel has been a popular bone tissue engineering material because of its excellent biocompatibility and minimally invasive injection, but there are still problems such as insufficient strength and poor cell adhesion. OBJECTIVE: To construct the negatively charged hydrogels by introducing sodium methacrylate into photocrosslinked alginate hydrogels, and to explore the changes in its physical performance and cell adhesion. METHODS: After preparation of methacrylated alginate by reacting sodium alginate with 2-aminoethyl methacrylate, methacrylated alginate, photoinitiator and sodium methacrylate (0, 20, 40, 60 mmol/L) were homogeneously mixed. The negatively charged photocrosslinked alginate hydrogels were prepared under ultraviolet light. The functional groups of the hydrogels were analyzed by fourier transform infrared spectroscopy. The surface morphology of the hydrogels was observed by scanning electron microscopy and the swelling ratio was measured. MC3T3-E1 cells were cultured with each group of hydrogels for 48 hours, and the cytotoxicity of the hydrogels was investigated by cell counting kit-8 assay. MC3T3-E1 cells were seeded on the surface of each group of hydrogels. The early adhesion of the cells was observed by live/dead staining at the 4th hour, and cell spreading was observed on the 3rd day. RESULTS AND CONCLUSION: (1) Fourier transform infrared spectroscopy demonstrated that the introduction of sodium methacrylate could lead to a new peak at wavenumber of about 1 600 cm-1 in the hydrogel infrared wave, which was from the sodium methacrylate. (2) Scanning electron microscope observed that the density of the negatively charged photocrosslinked alginate hydrogels increased and the pore size of the gels decreased with augment of concentrations of sodium methacrylate. (3) The swelling ratio of the hydrogel decreased with the increase of the concentration of sodium methacrylate. (4) The live/dead staining revealed that the cells grew well on the surface of each hydrogel, and the cell viability reached above 95%. The cell counting kit-8 assay results showed that the negatively charged photocrosslinked alginate hydrogels had no cytotoxicity. (5) The early cell adhesion rate increased gradually and the cell extension became better with the increase of concentration of sodium methacrylate. (6) In summary, the introduction of sodium methacryl into photocrosslinked alginate hydrogels can adjust its physical properties and significantly improve its cell adhesion.

Sodium Alginate Nanoparticles Of Isonizid: Preparation And Evaluation

Fabrication and evaluation of the Isoniazid loaded sodium alginate nanoparticles (NPs) was main objective of current investigation. These NPs were engineered using ionotropic gelation technique. The NPs fabricated, were evaluated for average particle size, encapsulation efficiency, drug loading, and FTIR spectroscopy along with in vitro drug release. The particle size, drug loading and encapsulation efficiency of fabricated nanoparticles were ranging from 230.7 to 532.1 nm, 5.88% to 11.37% and 30.29% to 59.70% respectively. Amongst all batches studied formulation F-8 showed the best sustained release of drug at the end of 24 hours.

Nanocomposite hydrogel-based biopolymer modified with silver nanoparticles as an antibacterial material for wound treatment

Authors report the synthesis of sodium alginate-polyvinyl alcohol-g-acrylamide (NaAlg-PVA-g-AAm) nanocompositehydrogels modified with silver nanoparticles (AgNPs) as an antibacterial agent. In this work, we used NaAlg isolateddirectly from brown algae and studied the effects of the NaAlg weight ratio and silver-ion concentration on the networkmatrix in the hydrogels via in situ polymerization. Successfully synthesized nanocomposites were characterized usingFourier transform infrared, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, andatomic absorption spectrometry. The best results were achieved with an average AgNPs size of approximately 20 nmallowing the AgNPs to be absorbed in the nanocomposite hydrogel matrix. Nanocomposite hydrogels displayed goodantibacterial activity against Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentrations(MICs) of silver nitrate (AgNO3) for E. coli and S. aureus were 46.251 and 75.220 ppm, respectively. Conversely,the minimum bactericidal concentrations (MBCs) of AgNO3 for these bacteria were 185.004 and 300.880 ppm,respectively. The MBC/MIC ratio of the AgNO3 modified nanocomposite hydrogels was four for both bacteria. Theresults illustrated that the nanocomposite hydrogels had good antibacterial activity against Gram-positive and Gramnegative bacteria and can be suitable for applications in wound treatments.

Development and evaluation of liquid oral controlled release systems for Losartan potassium

Losartan potassium is a water soluble antihypertensive agent with short half-life. Controlling its release will improvepatient compliance. The benefit will be extended for geriatric patients if the developed system was liquid. The objectiveof this work was to develop controlled release oral liquid losartan potassium. This employed a combination of in situgelation and coating drug particles with pH-dependent polymer (Eudragit® L100). Solid dispersion (SD) prepared at1:1, 1:1.5, and 1:2 drug : polymer ratios, respectively. Sodium alginate solution was loaded with either pure drug orSD, in presence and absence of 1% w/v chitosan. These systems were evaluated for the drug release using continuouspH variation study. Alginate formulation with pure drug underwent in situ gelation in the gastric conditions but lost thegelling strength in the intestinal phase with burst drug release. Loading the formulation with SD resulted in controlleddrug release both in the gastric and intestinal phases. Increasing eudragit concentration in SD decreased the drugreleased with total release efficiency of 62.1%, 53.0%, and 41.7%. Incorporation of chitosan at reduced further drugrelease rate reaching 21% at the higher eudragit concentration. The study provided the formulator with a range of oralliquid formulations for controlled release of losartan potassium.

Drumstick Mucilage Microspheres For Controlled Release Of Lamivudine: Design, Optimization And In Vitro Evaluation

Objective: The objective of this study was to design and evaluate controlled release mucoadhesive microspheres of lamivudine using mucoadhesive polymers and mucilage. Methods: Mucoadhesive microspheres of lamivudine were formulated by ionic gelation method. The response surface methodology was adapted for optimization of formulation using central composite design (CCD) for two factors at three levels each was employed to study the effect of independent variables, Sodium alginate-drumstick mucilage (X1) and calcium chloride (CaCl2) concentration (X2) on dependent variables, namely drug encapsulation efficiency (DEE) and particle size (PS). Optimized drumstick mucilage mucoadhesive microspheres of lamivudine were obtained by using numerical optimization of desirability approach. The observed microspheres were coincided well with the predicted values by the experimental design. Results: The microspheres formed were spherical in shape, and Particle size (PS) ranged between 681.63-941.57μm. Drug encapsulation efficiency (DEE) was ranged between 69.63-94.56 %. The drug release for an optimized formulation was 96.58 %. The mechanism of drug release from microspheres followed Korsemeyer’s-Peppas and exponential ‘n’ value was greater than 0.45, indicating the drug release was non-fickian i.e., swelling followed by erosion mechanism. Conclusion: This work suggests that mucoadhesive microspheres, an effective drug delivery system for lamivudine, can be prepared using drumstick mucilage in improving the bioavailability of the drug.

Encapsulation of flaxseed oil extract in alginate-salep system by ionic gelation

The objective of the current study was to encapsulate flaxseed oil extracted from finely grounded flaxseed powder and determined for its fatty acids content by GC/FID. Ionotropic gelation method was used to form beads containing 40% flaxseed oil with vitamin E being used as an antioxidant agent. The study employed calcium chloride solution as crosslinking agent with a combination of sodium alginate and salep. The effect of polymer concentrations and calcium chloride concentration on the morphology, entrapment efficiency and oil release was studied. The encapsulation efficiency reached 93.46 ± 0.064% using 0.6% of salep and 2% sodium alginate with 0.3M calcium chloride gelling solution. In SGF medium, the matrix released only about 28.56% of the entrapped flaxseed oil after 2 hours. The rest of the oil then released in the SIF medium, continuing for up to 5 h to release 99.32% of the oil.

Preparation and evaluation of carboxymethyl chitosan/sodium alginate hydrogel for cartilage tissue engineering / 华西口腔医学杂志

OBJECTIVE@#This study aimed to optimize the preparation of carboxymethyl chitosan/sodium alginate (CMCS/OSA) compound hydrogels. This study also aimed to investigate the applicability of the hydrogels in cartilage tissue engi-neering.@*METHODS@#Three groups of CMCS/OSA composite hydrogels with amino-to-aldehyde ratios of 2∶1, 1∶1 and 1∶2 were prepared. The microstructure, physical properties, and cell biocompatibility of the three groups of CMCS/OSA com-posite hydrogels were evaluated. Samples were subjected to scanning electron microscopy, rheological test, adhesion tension test, swelling rate test, and cell experiments to identify the CMCS/OSA composite hydrogel with the cross-linking degree that can meet the requirements for scaffolds in cartilage tissue engineering.@*RESULTS@#The experimental results showed that the CMCS/OSA hydrogel with a amine-to-aldhyde ratio of 1∶1 had good porosity, suitable gelling time, strong adhesive force, stable swelling rate, and good cellular biocompatibility.@*CONCLUSIONS@#The CMCS/OSA compound hydrogel prepared with a 1∶1 ratio of amino and aldehyde groups has potential applications in cartilage tissue engineering.

Edible active coatings incorporated with Cinnamomum cassia and Myristica fragrans essential oils to improve shelf-life of minimally processed apples / Revestimentos comestíveis ativos contendo óleos essenciais de Cinnamomum cassia e Myristica fragrans para aumentar a vida útil de maçãs minimamente processadas

ABSTRACT: The effect of the incorporation of cinnamon (Cinnamomum cassia) and nut meg (Myristicafragrans) essential oils in alginate-based edible coatings that were applied on minimally processed apples, is reported. The minimum inhibitory concentrations were 1.25mg.mL-1 (cinnamon) and 2.50mg.mL-1 (nutmeg), against both Escherichia coli and Penicillium commune. Over storage periods there was a significant reduction in the E. coli and P. commune counts compared to the control. The extent of enzymatic browning was also significantly reduced in the coated samples. In the coated minimally processed apples sensory tests, the flavor had the lowest rating of the properties analyzed, for both treatments, followed by aroma and firmness.

RESUMO: O efeito da incorporação dos óleos essenciais de canela (Cinnamomum cassia) e noz-moscada (Myristicafragrans) em revestimentos comestíveis à base de alginato, aplicados em maçãs minimamente processadas é apresentado. As concentrações inibitórias mínimas foram de 1,25mg.mL-1 (canela) e 2,50mg.mL-1 (noz-moscada), contra Escherichia colie Penicillium commune. Durante o armazenamento, houve redução significativa nas contagens de E.coli e P. Commune em comparação com o controle. A extensão do escurecimento enzimático também foi significativamente reduzida nas amostras revestidas. Nas análises sensoriais, o sabor dos óleos essenciais apresentou a menor classificação das propriedades analisadas, tanto para os óleos essenciais, quanto para aroma e firmeza.