Assessment of apoptosis and oxidative stress in cryopreserved ovary after grafting in fibrin-alginate scaffold with endothelial cells and melatonin in wistar rats.

OBJECTIVE: Infertility is a significant public health concern affecting 10-15% of couples. Young women undergoing gonadotoxic treatment are at higher risk of ovarian dysfunction and infertility. To mitigate this risk, ovarian tissue freezing and transplantation have been developed as a novel strategy. However, challenges such as follicular loss and dysfunction during the freezing process, and ovarian damage during transplantation, persist. This study aimed to investigate the potential of using appropriate antifreeze, antioxidant, wound healing, and biological hydrogels to reduce these injuries. Specifically, the effect of fibrin scaffold with endothelial cells and melatonin on apoptotic gene expression and antioxidants in cryopreserved ovaries after transplantation was examined. METHODS: A total of 36 adult female wistar rats) 6-8-week-old and weighing from 200 to 220 g) were divided equally into six groups (n = 6): 1) control group (C), 2) transplanted ovarian tissue after vitrification and thawing process (Group 1), 3) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel (Group 2), 4) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel in addition with melatonin (Group 3), 5) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel in addition with endothelial cells (Group 4) and 6) transplanted vitrified/thawed ovarian tissue while encapsulated in Fib/Alg hydrogel in addition with melatonin endothelial cells (Group 5). The ovaries were auto-transplanted in the rats' lumbar region. After 14 days, the ovaries were removed. Antioxidant levels (SOD, GPx, MDA, and TAC) were evaluated using ELISA, and apoptotic gene expressions (Bax/Bcl2 and caspase 3) were analyzed by real-time RT-PCR to determine apoptosis. RESULTS: In the transplanted frozen ovary group, Bax/Bcl2 and caspase 3 gene expression increased significantly (P<0.05), while antioxidant levels (SOD, GPx, MDA, and TAC) decreased. The encapsulated frozen ovary group showed decreased gene expression and increased antioxidant levels. The ovary group encapsulated with fibrin scaffold, endothelial cells, and melatonin had the most significant decrease in gene expression and increase in antioxidant levels (P<0.05). CONCLUSION: Coordinated action of Fibrin-based scaffold with endothelial cells and melatonin could decrease apoptosis gene expression and increase antioxidant levels in cryopreserved ovaries after transplantation, providing valuable insights into preserving fertility in young women undergoing gonadotoxic treatment.

Alginate composite films incorporated with Zn-based inorganic antimicrobials for food packaging: Effects of morphology.

Biopolymers-based food packaging materials have drawn attention as potential candidates for substitution of petroleum-based materials. In this study, composite alginate films were developed by incorporating Zn-based antimicrobials to overcome the intrinsic disadvantages of alginates that hinder their wide applications. Antimicrobials with different morphologies (nanoplatelets, nanorods, and nanospheres) were employed to investigate the effects of antimicrobials' morphology on antibacterial, thermal, mechanical, and barrier performance of composite alginate films. Meanwhile, morphological and structural characterizations were carried out to explore the interactions between antimicrobials and alginate matrix. Results indicated that films with nanospheres exhibited superior antibacterial property, while those with one-dimensional nanorods possessed better mechanical and barrier performance. Besides, preliminary test on fresh-cut potatoes and chicken breasts indicated that the composite films showed potential in extending shelf life of foods. By incorporating antimicrobials with three different morphologies, this study provides particular insights into improving properties of composite packaging materials.

Carbon dots-facilitated on-demand dissolution of Ca-alginate hydrogel via site-specific mineralization for wound healing.

On-demand dissolution of hydrogels has shown much potential in easy and pain-free removal of wound dressings. This work firstly describes a type of carbon dots (CDs) for dissolving Ca-alginate hydrogel via site-specific mineralization method. The CDs were characterized by two features, which included presence of primary/secondary amine groups and generation of calcium crystals with Ca2+. Especially, the amount of primary/secondary amine groups on CDs played key role in determining whether hydrogel could be dissolved. When there were sufficient primary/secondary amine groups, the mineralization occurred on CDs rather than alginates due to the hydrogen bond between primary/secondary amine and carboxyl of alginates. Thereby, this promoted the gel-sol transition through Ca2+ capture from the hydrogels. Moreover, antibacterial test revealed Ca2+ capture from cell walls, while in vivo test revealed hypoxia relief due to porous structures of the renewed hydrogels. Overall, CDs with sufficient primary/secondary amine groups could dissolve Ca-alginate hydrogel through site-specific mineralization method, accompanying by additional functions of antibacterial and hypoxia relief.

Evaluation of Surface Roughness of Acrylic Denture Bases Polished Using Algishine, a Novel Polishing Material: An In Vitro Study.

Introduction Surface roughness (Ra) significantly impacts the aesthetic and functional qualities of dental prosthetics. Traditional polishing involves pumice, a material routinely used in dental practice. This study introduces Algishine as a potential cost-effective eco-friendly alternative. Materials and methods A 3D design software (Geomagic) created a Standard Tesselation Language (STL) file of 10 mm x 10 mm x 2 mm. 30 STL file outputs were generated. The output was milled in wax. This was then flasked and processed. 30 acrylic resin specimens were fabricated and divided into two groups. Group A was polished using traditional pumice, and Group B was polished using Algishine. The Ra of each sample was measured using surface profilometry, with three readings per sample averaged for each group. Results Kruskal-Wallis test was performed to compare the two groups with the pre-testing samples, which showed p<0.05; indicating that there was a significant difference between the two groups. The average Ra value for unpolished acrylic was 7.105, while the specimens polished with pumice showed an Ra value of 2.218; specimens polished with novel material Algishine showed an Ra value of 1.743. This illustrates that Algishine achieves surface smoothness significantly superior to commonly used polishing agent and pumice. Discussion The results of our study demonstrate that Algishine, a novel polishing material derived from recycled alginate, effectively reduces the Ra of acrylic resin. This finding has significant implications, both clinically and environmentally. The primary clinical benefit of a smoother acrylic resin surface is the enhanced aesthetic appearance and increased patient comfort. A polished surface reduces plaque accumulation, thereby decreasing the risk of oral infections and improving the longevity of the dental prosthesis. The results show that Algishine achieves surface smoothness comparable to or better than pumice indicating that it can maintain, if not enhance, these clinical outcomes. Dental professionals can confidently use Algishine, knowing it meets the high standards required for patient care. Conclusion Algishine effectively reduces the Ra of acrylic resin, suggesting it is a viable, eco-friendly alternative to traditional pumice for dental polishing procedures. This indicates potential benefits in maintaining clinical outcomes while promoting environmental sustainability.

Rhodamine 6G in Oxidized Sodium Alginate Polymeric Hydrogel for Photodynamically Inactivating Cancer Cells.

INTRODUCTION: As cancer therapy progresses, challenges remain due to the inherent drawbacks of conventional treatments such as chemotherapy, gene therapy, radiation therapy, and surgical removal. Moreover, due to their associated side effects, conventional treatments affect both cancerous and normal cells, making photodynamic therapy (PDT) an attractive alternative. METHODS: As a result of its minimal toxicity, exceptional specificity, and non-invasive characteristics, PDT represents an innovative and highly promising cancer treatment strategy using photosensitizers (PSs) and precise wavelength excitation light to introduce reactive oxygen species (ROS) in the vicinity of cancer cells. RESULTS: Poor aqueous solubility and decreased sensitivity of Rhodamine 6G (R6G) prevent its use as a photosensitizer in PDT, necessitating the development of oxidized sodium alginate (OSA) hydrogelated nanocarriers to enhance its bioavailability, targeted distribution, and ROS-quantum yield. The ROS quantum yield increased from 0.30 in an aqueous environment to 0.51 when using alginate-based formulations, and it was further enhanced to 0.81 in the case of OSA. CONCLUSION: Furthermore, the nanoformulations produced fluorescent signals suitable for use as cellular imaging agents, demonstrating contrast-enhancing capabilities in medical imaging and showing minimal toxicity.

Homogeneously complexed alginate-chitosan hydrogel microspheres for the viability enhancement of entrapped hepatocytes.

The future deployment of biomedicine fields will require a new generation of biodegradable, biocompatible, and non-toxic hydrogels. Alginate and chitosan, naturally occurring polymers, have gained significant interest for hydrogel applications. However, integrating chitosan within alginate-based hydrogels to form microspheres with homogeneous distribution and a tailored surface charge remains challenging. Herein, we report the design and fabrication of homogeneously complexed alginate-chitosan hydrogel microspheres, demonstrating their ability to enhance the viability and liver-specific functionalities of entrapped hepatocytes. By exploring and optimizing the pH and ratio of alginate and chitosan solutions, we achieved well-controlled physicochemical properties, including the degree of sphericity, hydrophilicity, charge property, and surface roughness. Unlike traditional alginate-based hydrogel microspheres, hepatocytes entrapped in homogeneous alginate-chitosan microspheres displayed enhanced viability and liver-specific functions, including albumin secretion, urea synthesis, and cytochrome P-450 enzymatic activity. This work illustrates a potential pathway for manufacturing functionalized microspheres with tunable mechanical properties and functionalities based on biocompatible alginate and chitosan for hepatocyte applications.

Alginate binding enhances the structural stability and potentiates the lytic activity of bacteriophage endolysin's partially folded conformation.

Polysaccharide polymers are increasingly being used as chaperon-like macromolecules in assisting protein folding of unfolded protein molecules. They interact with unfolded or partially folded proteins in a charge and conformation specific manner that results in the formation of stable protein-polysaccharide complexes. In most of the cases, the complex formation of protein-polysaccharide is driven via non-covalent interactions that have found to endorse the activity of proteins. T4L (18.7 kDa) and T7L (17 kDa) endolysins belong to the hydrolase and amidase class of peptidoglycan degrading enzymes. Both T4L and T7L exist in partially folded forms and are devoid of lytic activity at low pH conditions. In the current study, we assessed the binding of alginate with T4L and T7L at pH 7 and 3 using variety of biophysical and biochemical techniques. Spectroscopic studies revealed differential structural modulations of partially folded T4L and T7L upon their interaction with alginate. Further, the complex formation of alginate with partially folded T4L/T7L was confirmed by ITC and STEM. Additionally, the formed complexes of alginate with both T4L/T7L PF endolysins were found to be chemically and enzymatically stable. Moreover, such complexes were also marked with differential enhancement in their lytic activities at acidic pH conditions. This implied the potency of alginate as an excellent choice of matrix to preserve the structural and functional integrity of partially folded forms of T4L and T7L at highly acidic conditions.

Full maturation of in vitro Plasmodium falciparum oocysts using the AlgiMatrix 3D culture system.

BACKGROUND: Plasmodium falciparum oocysts undergo growth and maturation in a unique setting within the mosquito midgut, firmly situated between the epithelium and the basal lamina. This location exposes them to specific nutrient exchange and metabolic processes while in direct contact with the mosquito haemolymph. The limited availability of in vitro culture systems for growth of the various P. falciparum mosquito stages hampers study of their biology and impedes progress in combatting malaria. METHODS: An artificial in vitro environment was established to mimic this distinctive setting, transitioning from a 2D culture system to a 3D model capable of generating fully mature oocysts that give rise to in vitro sporozoites. RESULTS: A two-dimensional (2D) chamber slide was employed along with an extracellular matrix composed of type IV collagen, entactin, and gamma laminin. This matrix facilitated development of the optimal medium composition for cultivating mature P. falciparum oocysts in vitro. However, the limitations of this 2D culture system in replicating the in vivo oocyst environment prompted a refinement of the approach by optimizing a three-dimensional (3D) alginate matrix culture system. This new system offered improved attachment, structural support, and nutrient exchange for the developing oocysts, leading to their maturation and the generation of sporozoites. CONCLUSIONS: This technique enables the in vitro growth of P. falciparum oocysts and sporozoites.

Construction of immobilized laccase hydrogels via sodium alginate-dopamine/polyethylene glycol and its efficient degradation of dyeing wastewater.

Laccases with highly catalytic properties have been widely used in developing green applications for water remediation. However, the poor stability and low reutilization rate of free laccase make it difficult to be applied practically. Hence, in this study, an immobilized laccase was prepared using dopamine (DA) functionalized sodium alginate (SA)/polyethylene glycol (PEG) composite hydrogels to realize the recyclability of the laccase. The SA/PEG composite hydrogels, as the protective carrier for laccase, exhibited excellent catalytic stability in various interfering environments. After 30 days, Lac@SA-PDA/PEG beads could remain 70.23 % of the initial activity, as the residual activity of free laccase was only 12.35 %. When free laccase and Lac@SA-PDA/PEG beads were used for decolorization of Reactive Blue 19 (RB-19,100 mg/L), the degradation rate of Lac@SA-PDA/PEG is 6.88 times higher than free laccase. More importantly, the SA-PDA/PEG composite hydrogel exhibited a high reutilization rate, which after six cycles, Lac@SA-PDA/PEG beads retained 90.23 % of its initial activity. Besides, the degradation effect of Lac@SA-PDA/PEG on different dyes was analyzed. In addition, the conjectured degradation pathways of RB-19 by laccase were analyzed. The work showed that immobilized laccase has tremendous potential for the treatment of dyestuff wastewater.

Propylene glycol alginate sodium sulfate suppressed lung metastasis by blocking P-selectin to recruit CD4 regulatory T cells.

P-selectin has been shown to enhance growth and metastasis of mouse tumors by promoting regulatory T cell (Treg) infiltration into the tumors. Theoretically, a P-selectin antagonist could suppress the process. Popylene glycol alginate sodium sulfate (PSS) is a heparin-like marine drug, which was originally approved to treat cardiovascular disease in China. Previously, we reported that PSS was an effective P-selectin antagonist in vitro. However, it is unknown whether PSS can regulate Treg infiltration and its effect on lung metastasis in vivo. Our results showed that PSS at 30 mg/kg significantly suppressed lung metastasis and improved overall survival, with potency comparable to the positive control LMWH. Mechanistic study indicated that PSS blocked tumor cells adhesion and activated platelets by directly binding with activated platelet's P-selectin. Compared to the model group, PSS decreased the percent of Tregs by 63 % in lungs after treating for 21 days while increasing CD8+ T cells (1.59-fold) and Granzyme B+ CD8 T cells (2.08-fold)' percentage for generating an adaptive response for systemic tumor suppression. The study indicated that the P-selectin antagonist, PSS, suppressed lung metastasis by inhibiting the infiltration of regulatory T cells (Treg) into the tumors.

Absorbable and biodegradable enzyme-crosslinked gelatin/alginate semi-IPN hydrogel wound dressings containing curcumin.

Effective wound management presents a substantial financial and time-related obstacle for healthcare institutions. Enhancing healthcare involves implementing innovative wound treatment methods to minimize healing time and expenses. This study is centered on the development of a non-toxic wound dressing using only two natural polymers and an enzyme. By adding 10 % wt microbial transglutaminase, the mechanical properties of the dressing were improved. This formulation increased the swelling rate by 70 %, deswelling rate by 15 %, conversion rate by 9 %, and networking rate by 20 %. Additionally, the non-toxic dressing showed a cell viability rate of 106 %. In drug delivery tests, explosive release behavior was observed, which is advantageous for open wounds. Cell staining experiments were also carried out to evaluate wound behavior in terms of collagen formation, granulation, and inflammation. The results suggest that the optimized hydrogel has great potential as a wound dressing. Its excellent absorption, antioxidant, and biocompatibility characteristics enhance tissue granulation rate and reduce wound treatment time by half compared to conventional methods, while also minimizing scarring risk. This innovative treatment, which eliminates the need for frequent changes, is beneficial for both secondary intentions and severe open wounds requiring bottom-up healing.

Formation of ovarian organoid by co-culture of human endometrial mesenchymal stem cells and mouse oocyte in 3-dimensional culture system.

The purpose of this study was to compare the formation of organoid structures by co-culturing of human endometrial mesenchymal stem cells (hEnMSCs) and mouse germinal vesicle (GV) oocytes in hanging drop and sodium alginate hydrogel co-culture methods. Following the preparation of hEnMSCs and partially denuded mouse germinal vesicle oocytes, they were co-cultured in hanging drop and sodium alginate hydrogel systems as two experimental groups. In respected control groups the hEnMSCs were cultured without oocytes. The organoid formation was evaluated under the inverted microscope in all studied groups during the culture period. The hematoxylin and eosin, alcian blue, periodic acid Schiff, and Masson's trichrome methods, were applied for morphological evaluation and extracellular matrix components staining such as glycosaminoglycan, carbohydrate, and collagen fibers. In addition, the germ cell-like characteristics within the organoid structures were investigated via alkaline phosphatase activity immunocytochemistry for DEAD-box polypeptide 4 (DDX4), and the expression of octamer-binding transcription factor 4 (OCT4), DDX4, and synaptonemal complex protein 3 (SYCP3) genes by real-time RT-PCR. The culturing of hEnMSCs in the hanging drop method led to the formation of organoid structures while this structure was not seen in sodium alginate hydrogel culture. The mean diameter of organoid structures was increased during 4 days of culture in both the experimental and control groups in the hanging drop method, reaching 675.50 ± 18.55 µm and 670.25 ± 21.40 µm, respectively (P < 0.05). Morphological staining indicated some large ovoid cells with euchromatin nuclei in the experimental group, whereas, in the control group cells showed dark and dense nuclei. The extracellular matrix components were deposited in organoid structures in both control and experimental groups. The positive alkaline phosphatase activity and immunocytochemistry for DDX4 confirmed the presence of germ cell-like in the experimental group. Real-time RT-PCR showed a significant increase in the expression of DDX4 and SYCP3 genes and a decrease in the level of OCT4 expression in the experimental group compared with its controls. This study successfully generated organoid structures by co-culture of hEnMSCs and oocytes in the hanging drop method and the hEnMSCs could be differentiated into germ cell-like. This organoid structure has potential applications in regenerative medicine and reproductive biology. Supplementary Information: The online version contains supplementary material available at 10.1007/s10616-024-00639-w.

Unveiling the potential of alginate-based nanomaterials in sensing technology and smart delivery applications.

Sensors are applied to many fields nowadays because of their high sensitivity, low cost, time-saving, user-friendly, and excellent selectivity. Current biomedical and pharmaceutical science has one focus on developing nanoparticle-based sensors, especially biopolymeric nanoparticles. Alginate is a widely used biopolymer in a variety of applications. The hydrogel-forming characteristic, the chemical structure with hydroxy and carboxylate moieties, biocompatibility, biodegradability, and water solubility of alginate have expanded opportunities in material and biomedical sciences. Recently, research on alginate-based nanoparticles and their applications has begun. These materials are gaining popularity because of their wide usage potential in the biomedical and pharmaceutical fields. Many review papers describe applications of alginate in the drug delivery field. The current study covers the structural and physicochemical properties of alginate-based nanoparticles. The prospective applications of alginate-based nanomaterials in various domains are discussed, including drug delivery and environmental sensing applications for humidity, heavy metals, and hydrogen peroxide. Moreover, biomedical sensing applications of alginate-based nanoparticles regarding various analytes such as glucose, cancer cells, pharmaceutical drugs, and human motion will also be reviewed in this paper. Future research scopes highlight existing challenges and solutions.

Alginate oligosaccharides exert protective effects on hydrogen peroxide-induced senescence in H9C2 cardiomyocytes by regulating the redox state of cells.

Aging is a known independent risk factor for several cardiovascular diseases. Here, we evaluated potential effects and possible mechanisms through which alginate oligosaccharides (AOS) affect hydrogen peroxide (H2O2)-induced senescence in H9C2 cardiomyocytes. A series of AOS molecules, including oligoM, oligoG, M-5, and G-5, were investigated. AOS significantly decreased SA-ß-gal and DAPI-stained positive cells, downregulated p53 and p21 (aging-related markers) expression, and eventually protected H9C2 cells from H2O2-induced senescence. AOS decreased reactive oxygen species and malondialdehyde production, recovered mitochondrial function, and alleviated the oxidative stress state by regulating PGC-1α and NADPH oxidase subunit expression. Furthermore, AOS treatment restored the expression of antioxidant enzymes in senescent H9C2 cells. Thus, our results show in vitro evidence that AOS alleviate senescence in H9C2 cells by regulating the redox state; thus, AOS may be an effective therapeutic agent that could protect against cardiomyocyte senescence.

Alginate-based hydrogels mediated biomedical applications: A review.

With the development in the field of biomaterials, research on alternative biocompatible materials has been initiated, and alginate in polysaccharides has become one of the research hotspots due to its advantages of biocompatibility, biodegradability and low cost. In recent years, with the further understanding of microscopic molecular structure and properties of alginate, various physicochemical methods of cross-linking strategies, as well as organic and inorganic materials, have led to the development of different properties of alginate hydrogels for greatly expanded applications. In view of the potential application prospects of alginate-based hydrogels, this paper reviews the properties and preparation of alginate-based hydrogels and their major achievements in delivery carrier, dressings, tissue engineering and other applications are also summarized. In addition, the combination of alginate-based hydrogel and new technology such as 3D printing are also involved, which will contribute to further research and exploration.

Synergistic enhancement of chlorophenols removal using eco-friendly alginate@montmorillonite hybrid bio-capsules: insights from encapsulation and kinetic release studies.

This study investigates the synergistic effects of alginate@montmorillonite (Alg@Mt) hybrid microcapsules for enhancing water purification, focusing on improving the encapsulation of hydrophobic contaminants. Alg@Mt microcapsules were prepared through ionotropic gelation. Characterisation was performed using SEM-EDX, FTIR, XRD, and TGA. Encapsulation efficiency (EE), loading capacity (LC), and release behaviour were also examined. Alg@Mt microcapsules effectively removed phenol and its chlorinated derivatives from water. Incorporating Na-Mt improved structural and thermal properties, EE, and LC. Increasing the clay content to 60% (w/w) raised the EE of phenol and its more hydrophobic derivative, 2,4,6-trichlorophenol, from 39.74 ± 3.1% (w/w) and 63.91 ± 2% (w/w) to 60.56 ± 1.6% (w/w) and 82.28 ± 2.3% (w/w), respectively, with more controlled release rates, following Fickian diffusion mechanism. EE increased with phenolic substances hydrophobicity, while LC and release rates were inversely related. This approach is promising for removing hydrophobic contaminants from water.

Exploring the cationic surfactant adsorption efficiency at concentrations relative to the critical micelle concentration by SA/SiO2 microspheres.

Studying the adsorption behavior of cationic surfactants can help to develop more effective strategies to limit their dispersion in the environment. However, there have few studies on the adsorption of cationic surfactants from the perspective of critical micelle concentration (CMC). In this study, with cetyltrimethylammonium bromide (CTAB) and octadecyl trimethylammonium bromide (OTAB) serving as the model cationic surfactants, the effect of CMC on the adsorption behavior of cationic surfactant onto the surface of sodium alginate/silica (SA/SiO2) microspheres was systematically revealed. The adsorption mechanism relative to CMC was investigated under different conditions, including surfactant concentration, pH, temperature, and adsorption time. The results suggest that at identical concentrations, the smaller the CMC value of the cationic surfactants, the greater the adsorption amount (qt). qt for CTAB and OTAB were 583.2 and 678.0 mg/g respectively, with the concentration higher than their CMC value. When the concentration was lower than the CMC value of the cationic surfactants, qt for CTAB and OTAB were 123.2 and 138.7 mg/g, respectively. The CMC value of CTAB was lower than that of OTAB under identical conditions, suggesting that the adsorption of cationic surfactants is related to their CMC. These results are beneficial for the removal of cationic surfactants by adsorption methods.

Gingerol containing polymeric nanofibers: a healing touch for accelerated wound recovery.

OBJECTIVE: In the current research, 6-gingerol (GA)-loaded nanofiber drug delivery system were developed, and their potential usage in wound healing was evaluated. SIGNIFICANCE: This study investigates the effectiveness of nanofibrous membranes composed of sodium alginate (SA), poly(vinyl alcohol) (PVA), and 6-gingerol (GA) as delivery systems for anti-inflammatory agents in the context of wound dressings. METHODS: GA-loaded SA/PVA nanofiber was prepared using electrospinning. In vitro characterization of this nanofiber included the examination of comprehensive in vitro characterization, anti-inflammatory and antioxidant activities, cytotoxicity, a scratch tes and in vivo skin test. RESULTS: GA was extracted from Zingiber officinale, and its successful isolation was confirmed through analyses such as H-NMR, C-NMR. Then GA was electrospuned into the SA/PVA nanofibers, and scanning electron microscopy (SEM) imaging revealed that the fiber diameters of the formulations ranged between 148 nm and 176 nm. Anti-inflammatory and antioxidant studies demonstrated that the effectiveness of GA increased with higher doses; however, this increase was accompanied by decreased cell viability. In vitro release studies revealed that GA exhibited a burst release within the first 8 h, followed by a controlled release, reaching completion within 24 h. Within the scope of in vitro release kinetics, release data are mathematically compatible with the Weibull model with high correlation. The scratch test results indicated that TB2 (%1 GA) promoted epithelialization. Furthermore, it was determined that TB2 (%1 GA) did not cause any irritation. CONCLUSIONS: As a result, TB2 shows promise as a formulation for wound dressings, offering potential benefits in the field of wound care.

Interfacial engineering of Pickering emulsions stabilized by pea protein-alginate microgels for encapsulation of hydrophobic bioactives.

This study aims to investigate the effects of interfacial layer composition and structure on the formation, physicochemical properties and stability of Pickering emulsions. Interfacial layers were formed using pea protein isolate (PPI), PPI microgel particles (PPIMP), a mixture of PPIMP and sodium alginate (PPIMP-SA), or PPIMP-SA conjugate. The encapsulation and protective effects on different hydrophobic bioactives were then evaluated within these Pickering emulsions. The results demonstrated that the PPIMP-SA conjugate formed thick and robust interfacial layers around the oil droplet surfaces, which increased the resistance of the emulsion to coalescence, creaming, and environmental stresses, including heating, light exposure, and freezing-thawing cycle. Additionally, the emulsion stabilized by the PPIMP-SA conjugate significantly improved the photothermal stability of hydrophobic bioactives, retaining a higher percentage of their original content compared to those in non-encapsulated forms. Overall, the novel protein microgels and the conjugate developed in this study have great potential for improving the physicochemical stability of emulsified foods.

Vascular tissues bioprinted with smooth muscle cell-only bioinks in support baths mimic features of native coronary arteries.

This study explores the bioprinting of a smooth muscle cell-only bioink into ionically crosslinked oxidized methacrylated alginate (OMA) microgel baths to create self-supporting vascular tissues. The impact of OMA microgel support bath methacrylation degree and cell-only bioink dispensing parameters on tissue formation, remodeling, structure and strength was investigated. We hypothesized that reducing dispensing tip diameter from 27G (210 µm) to 30G (159 µm) for cell-only bioink dispensing would reduce tissue wall thickness and improve the consistency of tissue dimensions while maintaining cell viability. Printing with 30G tips resulted in decreased mean wall thickness (318.6 µm) without compromising mean cell viability (94.8%). Histological analysis of cell-only smooth muscle tissues cultured for 14 days in OMA support baths exhibited decreased wall thickness using 30G dispensing tips, which correlated with increased collagen deposition and alignment. In addition, a TUNEL assay indicated a decrease in cell death in tissues printed with thinner (30G) dispensing tips. Mechanical testing demonstrated that tissues printed with a 30G dispensing tip exhibit an increase in ultimate tensile strength compared to those printed with a 27G dispensing tip. Overall, these findings highlight the importance of precise control over bioprinting parameters to generate mechanically robust tissues when using cell-only bioinks dispensed and cultured within hydrogel support baths. The ability to control print dimensions using cell-only bioinks may enable bioprinting of more complex soft tissue geometries to generate in vitro tissue models.