Effect Of Alginate Concentration Research Articles

Effect of alginate concentration on the physicochemical characteristics and entrapment efficiency of bioactive compounds in microencapsulated bekasam extract

Bekasam extract functions as an effective agent for reducing cholesterol and hypertension levels. One of the practical methods to utilize this extract is through microencapsulation. During the manufacturing of consumables, microcapsules can be incorporated into foods and beverages as functional additives. Therefore, this study aimed to investigate microencapsulation methods of bekasam extract, specifically by using ionic gelation with sodium alginate as a coating at varying concentrations of 0.50%, 0.75%, 1.00%, and 1.25%. The results showed that the diameter of the microcapsules produced ranged from 3.71-3.92 mm, and the yield was 21.83-40.47%. The microcapsules contained 6.3-10.08% peptides and 37.89-46.39 ppm of Lovastatin with an entrapment efficiency of 17.31- 27.69% and 59.08-72.76%, respectively. The microcapsules made with alginate (1.25%) had higher levels of Lovastatin and peptides.

Alendronate releasing silk fibroin 3D bioprinted scaffolds for application in bone tissue engineering: Effects of alginate concentration on printability, mechanical properties and stability

3D bioprinting uses biomaterials combined with cells to develop living constructs. This study explores the optimization of natural polymers, including silk fibroin, gelatin, and alginate, as bioink for 3D bioprinting in bone tissue engineering. The physicochemical properties of the bioink were thoroughly examined, revealing high water uptake and reduced degradation rate due to the addition of silk fibroin. The compressive modulus increased with higher alginate concentration. Rheological analysis confirmed shear-thinning properties and viscoelasticity of the ink. Through meticulous parameter optimization, the ink achieved the highest print accuracy with 4 % w/v alginate content. The printed scaffolds exhibited both macro and micro porosity, making them suitable for bone tissue regeneration. Furthermore, the scaffolds remained stable in culture medium for 36 days. The optimal composition for the hydrogel was determined to be a blend of 5 % fibroin, 7 % gelatin, and 4 % alginate in equal ratios. The bioink demonstrated excellent biocompatibility and, when supplemented with alendronate, enhanced alkaline phosphatase activity in MG-63 osteoblast-like cells. This finding indicates the commitment of cells toward the osteoblastic phenotype. Overall, this study successfully optimized the bioink and bioprinting process for bone tissue engineering applications, highlighting its promising potential for future advancements in the field.

Aplikasi Edible Coating Berbasis Tepung Biji Nangka dan Alginat Terhadap Kualitas Buah Tomat

<em>Enhancing post-harvest handling is crucial to boost productivity, preserve product quality, and enhance the competitiveness of food commodities. One effective approach to maintain product quality is by using edible coating, and in this case, alginate-based edible coating has been employed. The alginate-based edible coating exhibits a deficiency in terms of its inadequate mechanical properties. The addition of starch could improve the mechanical properties of alginate-based edible coating. Jackfruit seed starch has the potential to valorize as a cost-effective source of starch. Jackfruit seed flour has unique starch characteristics related to acid resistance, thermal properties, and mechanical properties when compared with starch from other sources. This study aims to optimize the concentration of alginate and jackfruit seed flour in the preparation of tomato edible coating using Response Surface Methodology (RSM). The effect of alginate concentration (1-2% b/v) and jackfruit seed flour concentration (1-2% b/v) on mass loss (%) and color difference (ΔE) were investigated. The optimum condition was obtained at an alginate concentration of 1.5% b/v and jackfruit seed flour concentration of 1.0% b/v with the resulting tomato quality value of mass loss of 5.43% and color difference (ΔE) of 0.70.</em>

Survivability of probiotics in Pickering emulsion gels stabilized by salmon by-product protein / sodium alginate soluble complexes at neutral pH

Adequate amounts of live probiotics reaching the gut are necessary to maintain host health. However, the harsh environment during processing, the low pH of human gastric acid, and the high concentration of bile salts in the gut can significantly reduce survivability of probiotics. In this work, we propose a simple Pickering emulsion gels strategy to encapsulate Lactobacillus plantarum Lp90 into oil droplets filled in calcium alginate gels to improve its viability under pasteurization and gastrointestinal conditions. The emulsion gels were stabilized by the soluble complexes of salmon by-product protein (SP) and sodium alginate (ALG), and the aqueous phase was solidified by the addition of calcium. The interaction between SP and ALG and the effect of ALG concentration on emulsifying ability and emulsion stability were studied. The results from optical imaging, nuclear magnetic resonance, and rheological properties showed that the stability and viscosity of the emulsions gradually increased with the increased ALG concentration, while the droplet size of the emulsions and the content of free water in the system decreased significantly. Especially when the concentration of ALG was 1 %, the emulsion system was stable under the environment of high temperature and high ionic strength, and the water holding capacity was the highest. Through pasteurization and gastrointestinal digestion experiments, it was found that the survival rate of probiotics encapsulated in emulsion gels was significantly higher than that encapsulated in emulsions or hydrogels, which benefited from the dual action of oil droplets and calcium alginate gels network. These results provide a new strategy for the processing of probiotics and the high-value utilization of marine fish by-products.

Synthesis and characterization of natural fibers reinforced alginate hydrogel fibers loaded with diclofenac sodium for wound dressings

Hydrogels which become increasingly important in the biomedical field are composed of a three-dimensional hydrophilic network. Pure hydrogels are usually weak and brittle; therefore, reinforcements are assimilated into the hydrogel structure to improve the mechanical strength of the hydrogels. However, even if mechanical properties are enhanced, drapability remains an issue. In that regard, natural fiber-reinforced composite hydrogel fibers for wound dressing application are investigated in this study. Kapok and hemp fibers were used as reinforcement to improve the strength of hydrogel fibers. The properties of the prepared composite hydrogel fibers were studied with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimeter (DSC). The effect of alginate concentration and fiber weight percent on the mechanical characteristics and water absorbency was studied. Diclofenac sodium drug was loaded in the hydrogel fibers and investigated the drug release as well as antibacterial characteristics. Both fibers' reinforcement enhanced the strength of the alginate hydrogel fiber, but hemp reinforcement showed better mechanical properties. Kapok reinforcement resulted in a maximum tensile strength of 174 cN (1.24 % elongation) and 432 % exudate absorbency, while hemp reinforcement resulted in 185 cN (1.48 % elongation) and 435 % exudate absorbency. Statistical analysis revealed significant effects of sodium alginate concentration on tensile strength (p-value 0.042) and exudate absorbency (p-value 0.020) and of reinforcement (wt%) on exudate absorbency (p-value 0.043). Therefore, these composite hydrogel fibers with improved mechanical properties are capable of drug release and exhibit antibacterial effectiveness, making them a promising option for use as wound dressings.

The Effect of Alginate Concentration on Crystallinity, Morphology, and Thermal Stability Properties of Hydroxyapatite/Alginate Composite.

Hydroxyapatite (HAp) has been used for various applications such as orthopedics, drug delivery material, and bone tissue engineering. It is well known that HAp has a good biocompatibility and osteoconductivity, so HAp can be used in biomedical applications. Hydroxyapatite can be combined with other materials, in particular polymer, to expand its range of applications. In this study, the polymer that will be used as a support for the HAp composite is alginate (Alg). The HAp/Alg composite has been synthesized by the precipitation method. The XRD results show that the crystal system of HAp was hexagonal. The spheric-like shaped particles can be observed from SEM images, and particle size distribution spread from 400 to 1100 nm. The EDS spectrum exhibited the peak of Ca, C, P, and O elements, indicating that alginate had interacted with hydroxyapatite in the synthesized composite. The as-fabricated composite showed not only good crystallinity but also high thermal resistance. Thermogravimetric-differential thermal analysis (TGA-DTA) revealed that the HAp/Alg composites have a constant weight at 750 °C, so it might be applied in advanced applications such as bioimaging, drug carrier, and other cancer treatments.

The effect of alginate concentration on the viability of probiotics (Bacillus subtilis) in synbiotic microcapsule beads after incubation at 70°C

High temperatures in feed molding machines can cause a decline in probiotic populations in fish feed. Adding alginate in probiotic preparations is expected to wrap probiotics so that when added to the feed before pelleting, it does not experience a drastic decrease. This study investigated the decline in probiotic populations in fish feed caused by high temperatures in feed molding machines and evaluated the use of alginate in probiotic preparations to prevent drastic decreases in viability. The study aimed to determine the viability of Bacillus sp. in synbiotic microcapsule beads with varying levels of alginate concentration after exposure to 70°C. The research used four treatments and three replicates with a randomized complete design. The results showed that the alginate concentration affected the diameter of the beads of synbiotic microcapsules, but it did not significantly affect the viability of Bacillus sp. The viability of probiotics in alginate beads after exposure to 70°C was 5.182±0.527 - 5.720±0.072 log cfu/ml. Therefore, using alginate in probiotic preparations can be considered as a reference for adding probiotics to fish feed before pelleting to maintain the viability of the probiotics in high-temperature conditions.

Development of Antimicrobial Paper Coatings Containing Bacteriophages and Silver Nanoparticles for Control of Foodborne Pathogens.

In this study, a novel antimicrobial formula that incorporates Listeria bacteriophage P100 and silver nanoparticles into an alginate matrix was successfully developed. Paper coated with the antimicrobial formula inhibited the growth of Listeria monocytogenes. The effects of alginate concentration on the formation of silver nanoparticles, silver concentration on the infectivity of phages, and of low alginate concentrations on the sustained release of silver and phages were explored. The highest antimicrobial activity of the alginate-silver coating was achieved with an alginate concentration of 1%. Adding phage P100 (109 PFU/mL) into the alginate-silver coating led to a synergic effect that resulted in a 5-log reduction in L. monocytogenes. A bioactive paper was then developed by coating a base paper with the antimicrobial formula at different coating weights, followed by infrared drying. The higher coating weight was a crucial factor for the maintenance of phage infectivity throughout the coating and drying processes. Phages incorporated into the alginate matrix remained functional even after high-temperature infrared drying. Taken together, an optimized coating matrix is critical in improving the antimicrobial performance of bioactive paper as well as maintaining phage infectivity during the paper manufacturing process.

Millifluidic-assisted ionic gelation technique for encapsulation of probiotics in double-layered polysaccharide structure

A unique double-layered vehicle was fabricated for the first time based on a millifluidic/direct gelation to encapsulate probiotics. Free probiotic bacteria are usually very sensitive to severe gastrointestinal conditions and maintaining their survival when passing through the digestive tract is essential. The effects of alginate concentration (20–30 g/L), flow rates of alginate (0.8–1.2 mL/min), and W/O emulsion (0.5–0.7 mL/min) on encapsulation efficiency (EE), size, and sphericity of core–shell millicapsules were optimized for encapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus plantarum. The optimized calcium-alginate millicapsule was spherical (0.97 ± 0.01 SF), with an average diameter of 4.49 ± 0.19 mm, and encapsulation efficiency of 98.17 ± 0.5 %. Two strains were encapsulated separately in W/O emulsion as a core of the millicapsule. After coating with chitosan, the encapsulation yield of the bacteria, survival rates under simulated gastrointestinal (GI) conditions, and viability during storage were determined. Survival efficiency of B. animalis subsp. lactis and L. plantarum after millifluidic encapsulation were found to be 92.33 and 90.81 %, respectively. Cell viability of encapsulated probiotics after passing through the GI system was improved (7.5 log CFU mL−1 for both strains). Although the viability of the encapsulated probiotics stored at −18 °C for five months significantly decreased (p<0.05), the number of live cells was approximately in accordance with the standard definition of long-term probiotic survival (6 log CFU/g). This work provides a pathway for the construction of an innovative delivery system with high efficiency and protective effects for probiotics.

Cu2+/alginate nanofiltration membranes fabricated at the aqueous contra-diffusion “interface” for salt/dye rejection

Thin-film composite (TFC) membranes can find broad uses in desalination and wastewater treatment. However, industrialized interfacial polymerization involves many organic solvents and toxic monomers. An aqueous fabrication process can meet the standards of green and sustainable production, but fabricating defect-free thin films in a homogenous phase remains challenging. Herein, we fabricate a series of TFC nanofiltration membranes through a contra-diffusion process based on the cross-linking of metal ions and alginate. The film formation is confined at the ultrafiltration substrate surface due to the competition between reaction and restricted diffusion. Among a series of metal ion/alginate composites, the Cu2+/alginate composite membrane displays superior nanofiltration performance because of the strong affinity between Cu2+ and alginate. The highly negatively charged membrane performs a high rejection to divalent anions and anionic dyes based on the Donnan effect. The effects of alginate concentration and diffusion time on membrane performance were investigated to achieve optimal fabrication conditions. The as-prepared membrane shows a rejection of 96.2% to Na2SO4 with permeation flux around 50.2 L·m−2·h−1 under 0.6 MPa, and 99.5% to several dye molecules. Moreover, the membrane performs outstanding anti-fouling and anti-bacterial properties because of its excellent hydrophilicity and the existence of Cu2+.

Investigating the effects of precursor concentration and gelling parameters on droplet-based generation of Ca-Alginate microgels: identifying new stable modes of droplet formation

Droplet-based microfluidics is an attractive approach for producing microgels due to its high potential to control the size and shape of the particles and precisely entrap the substances within the hydrogel matrix. However, the microfluidic generation of monodisperse microgels with desired structures is still challenging. Indeed, the rheological and interfacial properties of the immiscible fluids, as well as the adopted gelling strategy, play important roles in microfluidic methods. Herein, sodium alginate droplets with different concentrations are generated via a microfluidic device with a flow-focusing unit. Besides, a combined in situ and ex situ strategy is optimized to crosslink sodium alginate droplets in the presence of calcium ions. The effects of alginate concentration and junction width in the flow focusing unit are investigated on droplet size and droplet formation regimes. It is observed that by increasing the alginate concentration, the dripping regime of droplet formation may be transformed to one of the binary dripping or quasijetting regimes. In the binary dripping regime, two successive different-sized droplets are generated in each period of droplet formation, which leads to low monodispersity in the collected droplets. However, the droplets produced in the quasijetting regime are interestingly monodisperse and also smaller than those of the dripping and binary dripping regimes. The breakup dynamics of the alginate thread is also analyzed with a computational fluid dynamics (CFD) code. This analysis discloses that the viscous stresses, as well as the viscous dissipation, have important roles in controlling the stable modes of droplet formation.

Droplet-based millifluidic technique for encapsulation of cinnamon essential oil: Optimization of the process and physicochemical characterization

The “millifluidic” technique could be considered as a novel approach for encapsulation of bioactive compounds and has a promising perspective in the field of food engineering or pharmaceutical science. In this study, we aim to optimize the encapsulation of cinnamon essential oil (CEO) by droplet-based millifluidic technique with four responses: encapsulation efficiency (EE), loading capacity (LC), sphericity factor (SF) and size of calcium-alginate millicapsules. The effects of alginate concentration (20–30 g/L), flow rate of alginate (1–1.6 mL/min), and flow rate of CEO (0.6–0.8 mL/min) were considered by a Box-Behnken design. The best concentration of chitosan as a coating layer on the optimized samples was selected based on the Young modulus of millicapsules. The regression models showed the significant effect (p < 0.05) of the three variables on the characteristics of millicapsules. The optimal millicapsules with 3.58 ± 0.23 mm diameter and 0.96 ± 0.01 S F showed 98.96 ± 1.2% and 70.14 ± 1.8% EE and LC, respectively. SEM images exhibited a rough external surface which changed to a rigid and smooth surface through the chitosan coating. The results of DSC and FTIR tests demonstrated the CEO entrapment in the millicapsules without any chemical interaction with the encapsulant materials. The disarray of crystallinity structure in XRD patterns revealed the successful encapsulation of CEO in the millicapsules. The non-Fickian case II in the mouth and small intestine and anomalous transport in the stomach were the main release mechanisms in the coated millicapsules. The release profile of CEO also fitted well with Ritger-Peppas model.

Optimization of microspheres containing virgin coconut oil and hydrolyzed virgin coconut oil as antimicrobial.

ABSTRACTVirgin Coconut Oil (VCO) with potential fatty acid content has a strong antibacterial effect for drug and cosmetics. VCO was hydrolyzed as hydrolyzed VCO (HVCO) to increase its activity. This study aims to optimize VCO and HVCO microspheres. Examination was included fatty acid content, density, and organoleptic. VCO and HVCO microspheres were characterized by yield, moisture content (MC), morphology, and size. Fatty acid content was done through gas chromatography mass spectrometry whereas for microspheres, effect of alginate concentration (1%–2%), and addition of poly ethylene glycol (PEG) were studied. VCO and HVCO microspheres formulas showed that an increase in polymer concentration, increasing yield, and improving MC. The most optimal 2% alginate with the addition of PEG increased yield up to 59% and reduced size. F4 microspheres resulted the highest yield, low MC, and high fatty acids. Morphology was spherical and smooth with small size. Optimization of HVCO microspheres showed its potential which recommend for antibacterial and antifungal activity.

Effects of Alginate Concentration and Ovarian Cells on In Vitro Development of Mouse Preantral Follicles: A Factorial Study.

BackgroundIn the present study, the effects of alginate (ALG) concentration and ovarian cells (OCs) on the devel- opment and function of follicles were simultaneously evaluated.Materials and MethodsIn the first step of this experimental study, preantral follicles were isolated from the ovaries of 2-week-old mice, encapsulated in the absence or presence of OCs in 0.5, 0.75 and 1% ALG hydrogels, and cultured for 14 days. The morphology, diameter, survival and antrum formation rates of the follicles and the maturation of the oocytes were evaluated during culture. In the second step, preantral follicles were cultured in the best chosen ALG concentration, in both the absence and presence of OCs. Following these steps, the amount of DNA fragmentation, the expression levels of connexin 37 and connexin 43 proteins, the secretion levels of estradiol, progesterone and andros- tenedione by the follicles and the quality of mature (MII) oocytes were assessed.ResultsOur data revealed that in the absence of OCs, follicles of 0.5% group showed a higher survival rate than the 0.75 and 1% groups (71.87 vs. 52.52 and 40%, respectively, P<0.05). Nonetheless, the antrum formation rate of the 1% group was higher and its oocyte degeneration rate was lower than that in the other groups. Furthermore, it was observed that co-culture of follicles with OCs relatively increased the follicle diameter, survival, antrum formation, and germinal vesicle (GV) to GV break down (GVBD)/MII transition rates. At last, the comparison of 0.5%-OCs and 0.5%+OCs groups indicated that the co-culture condition resulted in more progesterone production (1.8 ± 0.2 vs. 3.2 ± 0.4 ng/ml, respectively, P<0.05) and also decreased oocytes’ cortical granule abnormalities (100 vs. 40% for 0.5%- OCs and 0.5%+OCs groups, respectively).ConclusionThe present study revealed that 0.5% ALG hydrogel is relatively suitable for preantral follicle culture, and in the presence of OCs, it mimics the natural ovarian condition better than the higher concentrations of ALG hydrogel.

Three-Dimensional Bioprinting of Functional Skeletal Muscle Tissue Using GelatinMethacryloyl-Alginate Bioinks.

Skeletal muscle tissue engineering aims to fabricate tissue constructs to replace or restore diseased or injured skeletal muscle tissues in the body. Several biomaterials and microscale technologies have been used in muscle tissue engineering. However, it is still challenging to mimic the function and structure of the native muscle tissues. Three-dimensional (3D) bioprinting is a powerful tool to mimic the hierarchical structure of native tissues. Here, 3D bioprinting was used to fabricate tissue constructs using gelatin methacryloyl (GelMA)-alginate bioinks. Mechanical and rheological properties of GelMA-alginate hydrogels were characterized. C2C12 myoblasts at the density 8 × 106 cells/mL were used as the cell model. The effects of alginate concentration (0, 6, and 8% (w/v)) and crosslinking mechanism (UV crosslinking or ionic crosslinking with UV crosslinking) on printability, cell viability, proliferation, and differentiation of bioinks were studied. The results showed that 10% (w/v) GelMA-8% (w/v) alginate crosslinked using UV light and 0.1 M CaCl2 provided the optimum niche to induce muscle tissue formation compared to other hydrogel compositions. Furthermore, metabolic activity of cells in GelMA bioinks was improved by addition of oxygen-generating particles to the bioinks. It is hoped that such bioprinted muscle tissues may find wide applications in drug screening and tissue regeneration.

Effect of alginate concentration in wastewater nutrient removal using alginate-immobilized microalgae beads: Uptake kinetics and adsorption studies

Effect of alginate concentration on wastewater nutrient removal by alginate-immobilized microalgae bead systems (AIMS) of Chlorella vulgaris was investigated to delineate the underlying role of alginate matrix in the removal process. The study includes kinetic evaluation of nutrient removal in AIMS of different alginate concentration (1.5–4.5% w/v%) followed by an assessment of abiotic adsorption characteristics of blank alginate beads systems (BABS) of same alginate concentrations. Results establish 3% alginate concentration as optimal both for nutrient removal in AIMS and adsorption in BABS. The adsorption data in the latter fitted well with Langmuir isotherms, suggesting monolayer physisorption, which was later corroborated through Fourier-Transform Infrared Spectroscopy (FTIR) and Energy Dispersive X-ray (EDX) analysis. A scheme for adsorption of NH4+ - N and PO43−- P on alginate matrix through hydrogen bonding was illustrated. The optimal trends were explained based on pore morphology and bead structural integrity.

EVALUATION OF BACTERIAL CELLULOSE-SODIUM ALGINATE FORWARD OSMOSIS MEMBRANE FOR WATER RECOVERY

Water resources are very important to sustain life. However, these resources have been subjected to stress due to population growth, economic and industrial growth, pollution and climate change. With these, the recovery of water from sources such as wastewater, dirty water, floodwater and seawater is a sustainable alternative. The potential of recovering water from these sources could be done by utilizing forward osmosis, a membrane process that exploits the natural osmotic pressure gradient between solutions which requires low energy operation. This study evaluated the potential of forward osmosis (FO) composite membranes fabricated from bacterial cellulose (BC) and modified with sodium alginate. The membranes were evaluated for water flux and salt rejection. The effect of alginate concentrations and impregnation temperatures were evaluated using 0.6 M sodium chloride solution as feed and 2 M glucose solution as the draw solution. The membranes were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Contact Angle Meter (CAM). The use of sodium alginate in BC membrane showed a thicker membrane (38.3 μm to 67.6 μm), denser structure (shown in the SEM images), and more hydrophilic (contact angle ranges from 28.39° to 32.97°) compared to the pristine BC membrane (thickness = 12.8 μm and contact angle = 66.13°). Furthermore, the alginate modification lowered the water flux of the BC membrane from 9.283 L/m2-h (LMH) to value ranging from 2.314 to 4.797 LMH but the improvement in salt rejection was prominent (up to 98.57%).

Effect of Alginate Concentrations on Characteristics of Lactobacillus acidophilus and Their Viability

Lactobacillus acidophilus, a probiotic bacterium, is important bacteria for establishing a balanced intestinal microflora. The number of probiotic bacteria that must be consumed to get the benefits is about ≥107 CFU/g. Viability of L. acidophilus is generally low due to environmental conditions, storage and processing. Therefore, it is essential to maintain the number of bacteria, including the use of coating material followed by freeze drying. This microencapsulation method study aimed to determine the exact concentration of alginate in order to improve viability and attain best microcapsule characteristics by freeze drying method. A completely randomized design with 4 treatments and 4 replications was used. Alginate concentrations used were 1%, 2%, 3%, and 4% (w/v). They showed that no significantly difference on cell viability but a significant by different moisture content and yield of microcapsules. Treatment with 4% concentration was the best on generating microcapsules L. acidophilus with viability of 97.89%, water content of 3.43%, yield of 16.32%. It could also reduce resistance to pH 2.0 and bile salt 0.5% respectively 4.90 log cfu/g and 4.38%log cfu/g of total initial bacteria 4.99 log cfu/g. Keywords: alginate, microencapsulation, Lactobacillus acidophilus, viability and characteristics.

Effect of alginate concentration on chondrogenesis of co-cultured human adipose-derived stem cells and nasal chondrocytes: a biological study

BackgroundThe three-dimensional (3D) system is one of the important factors to engineer a biocompatible and functional scaffold for the applications of cell-based therapies for cartilage repair. The 3D alginate hydrogels system has previously been shown to potentially promote chondrogenesis. The chondrocytic differentiation of co-cultured adipose-derived stem cells (ADSCs) and nasal chondrocytes (NCs) within alginate constructs are hypothesized to be influenced by concentration of alginate hydrogel. In this study, we evaluated the effects of alginate concentration on chondrogenic differentiation of ADSCs and NCs co-cultured in a biological approach.MethodThe co-cultured cells of 2:1 ADSCs-to-NCs ratio were encapsulated in alginate constructs in one of three concentrations (1.0%, 1.2% and 1.5%) and cultured under serum free conditions for 7 days. Cell viability, cell proliferation, immunohistochemical, gycosaminogylycans (GAG) synthesis, and gene expression were examined.ResultsOverall, the 1.2% alginate concentration group was relatively effective in chondrocytic differentiation in comparable to other groups. The cell morphology, cell viability, and cell proliferation revealed initial chondrogenic differentiation by the formation of cell clusters as well as the high permeability for exchange of solutes. The formation of newly synthesis cartilage-specific extracellular matrix in 1.2% group was demonstrated by positive immunohistochemical staining of collagen type II. The co-cultured cells in 1.2% group highly expressed COL II, ACP and SOX-9, compared to 1.0% and 1.5% groups, denote the retention of cartilaginous-specific phenotype by suppressing the undifferentiation stem cell markers of SOX-2 and OCT-4. The study showed 1.2% group was less likely to differentiate towards osteogenesis by downregulating hyperthrophy chondrocytic gene of COL X and osseous marker genes of OSC and OSP.ConclusionThis study suggests that variations in the alginate concentration of co-cultured ADSCs and NCs influenced the chondrogenesis. The remarkable biological performance on chondrogenic differentiation in regulating the concentration of alginate 3D culture provides new insights into the cell cross-talk and demonstrates the effectiveness in regenerative therapies of cartilage defects in tissue engineering.

Prolonged injectable formulation of Nafarelin using in situ gel combination delivery system

The principal purpose of the present study was to prepare and characterize a complex drug delivery system consisting of Nafarelin-poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanoparticles (NPs) in combination with sodium alginate/poloxamer 407 in situ gel. Nafarelin-loaded PHBV NPs were prepared via double emulsion solvent evaporation technique. Box–Behnken Response Surface Methodology was utilized to optimize NPs. Mean particle size, polydispersity index (PDI), entrapment efficiency (EE), and drug loading (DL) of the optimized NPs were measured. Incorporation of Nafarelin within NPs was proven by differential scanning calorimetry (DSC). The combination delivery system (CDS) was prepared by adding Nafarelin-loaded PHBV NPs to sodium alginate/poloxamer 407 solution followed by physical mixing. Morphological properties of Nafarelin-loaded PHBV NPs and CDS were evaluated by SEM. Rheological properties were employed to investigate the effects of alginate concentration on sol–gel transition temperature. The release profile of Nafarelin from both PHBV NPs and CDS were individually assessed. The cumulative release percentage from CDS was significantly lower than Nafarelin released from PHBV NPs. Based on the favorable results in this study, the CDS consisting of sodium alginate/poloxamer 407 loaded with PHBV NPs could be a promising candidate for designing a long-lasting formulation of Nafarelin.