Reverse circumcision foreskin advancement flap for reconstructing penile shaft skin defects in adults with burn injuries in the perineal region.

AIM: Genital burns are rare injuries. Reconstruction of penile skin defects should consider cosmetic and functional outcomes. Skin grafts can develop scar contractures and carry hair follicles, causing unwanted results. These downsides remain unsolved issues. This work aimed to describe a new foreskin advancement flap method for completely reconstructing penile shaft skin defects in severely burned patients. MATERIALS AND METHODS: From 2021 to 2023, four patients with third-degree burns in the genital area were enrolled in this investigation. We describe a series of cases with deep burns to the penile shaft and surrounding area that needed debridement and reconstruction using a novel technique called "reverse circumcision," which consists of tangential excision of the penis and a foreskin advancement flap without longitudinal cuts with less morbidity, preservation of function, and a better aesthetic appearance. The patients had an average follow-up of nine months. RESULTS: The reverse circumcision technique was established for patients with severe burns in the genital area. The four patients were satisfied with the postoperative results and the aesthetic results of the procedure without reporting any complications. No scarring or contractures were observed on the glans or penile shaft after surgery. CONCLUSIONS: Compared with other flap methods, the use of a reverse circumcision foreskin advancement flap was more straightforward, feasible, and effective. In adults, the foreskin tissue completely covers the penile shaft skin defect. It is a viable reconstructive surgical technique that is easily reproducible and has excellent aesthetic and functional results. For this surgical technique, tissue transfers, bulky regional flaps, or skin grafts were not needed.

A randomized intraindividual comparative study evaluating the effects of two ultrasound-assisted liposuction devices on the abdomen.

BACKGROUND: Ultrasound-assisted liposuction (UAL) has become popular because of its favorable outcomes in fat emulsification, blood loss reduction, and skin tightening. This study aimed to compare the effects of two UAL devices on the abdomen by assessing postsurgery skin biomechanical properties. METHODS: This single-blind, prospective study (2020-2022) involved 13 liposuction procedures performed on patients without chronic diseases. Each patient's abdomen was divided vertically from the xiphoid to the perineum. Vibration amplification of sound energy at resonance (VASER)-assisted liposuction (Solta Medical, Inc., Hayward, CA) was performed on one half, while the other half underwent liposuction with high-frequency ultrasound energy (HEUS)-assisted technology. Skin biomechanical measurements, including distensibility, net elasticity, biological elasticity, hydration, erythema, melanin, and skin firmness, were taken at 12 and 24 months postsurgery, focusing on the anterior abdomen, 8 cm to the right and left of the umbilicus. RESULTS: Analysis of the above skin biomechanical measurements revealed no significant differences between the HEUS and VASER devices, except for skin firmness, which showed a notable increase following HEUS surgery. Patient-perceived clinical differences were assessed via nonvalidated questionnaires, revealing no distinctions between devices. CONCLUSION: Biomechanical skin results post-UAL surgery with these devices on the abdomen were not significantly different, although HEUS revealed increased skin firmness. This suggests that HEUS-assisted technology, akin to other devices, is a viable option for UAL procedures.

Preparation of xyloglucan-grafted poly(N-hydroxyethyl acrylamide) copolymer by free-radical polymerization for in vitro evaluation of human dermal fibroblasts.

Xyloglucan is a rigid polysaccharide that belongs to the carbohydrate family. This hemicellulose compound has been widely used in biomedical research because of its pseudoplastic, mucoadhesive, mucomimetic, and biocompatibility properties. Xyloglucan is a polyose with no amino groups in its structure, which also limits its range of applications. It is still unknown whether grafting hydrophilic monomers onto xyloglucan can produce derivatives that overcome these shortcomings. This work aimed to prepare the first copolymers in which N-hydroxyethyl acrylamide is grafted onto tamarind xyloglucan by free-radical polymerization. The biocompatibility of these structures in vitro was evaluated using human dermal fibroblasts. Gamma radiation-induced graft polymerization was employed as an initiator by varying the radiation dose from 5-25 kGy. The structure of the graft copolymer, Xy-g-poly(N-hydroxyethyl acrylamide), was verified by thermal analysis, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy. The findings indicate that the degree of grafting and the cytotoxicity/viability of the xyloglucan-based copolymer were independent of dose. Notably, the grafted galactoxyloglucan exhibited efficient support for human dermal fibroblasts, showing heightened proliferative capacity and superior migration capabilities compared to the unmodified polymer. This copolymer might have the potential to be used in skin tissue engineering.

Advances in chitosan and chitosan derivatives for biomedical applications in tissue engineering: An updated review.

In recent years, chitosan (CS) has received much attention as a functional biopolymer for various applications, especially in the biomedical field. It is a natural polysaccharide created by the chemical deacetylation of chitin (CT) that is nontoxic, biocompatible, and biodegradable. This natural polymer is difficult to process; however, chemical modification of the CS backbone allows improved use of functional derivatives. CS and its derivatives are used to prepare hydrogels, membranes, scaffolds, fibers, foams, and sponges, primarily for regenerative medicine. Tissue engineering (TE), currently one of the fastest-growing fields in the life sciences, primarily aims to restore or replace lost or damaged organs and tissues using supports that, combined with cells and biomolecules, generate new tissue. In this sense, the growing interest in the application of biomaterials based on CS and some of its derivatives is justifiable. This review aims to summarize the most important recent advances in developing biomaterials based on CS and its derivatives and to study their synthesis, characterization, and applications in the biomedical field, especially in the TE area.

Optimize the parameters for the synthesis by the ionic gelation technique, purification, and freeze-drying of chitosan-sodium tripolyphosphate nanoparticles for biomedical purposes.

BACKGROUND: Polymeric nanoparticles can be used for wound closure and therapeutic compound delivery, among other biomedical applications. Although there are several nanoparticle obtention methods, it is crucial to know the adequate parameters to achieve better results. Therefore, the objective of this study was to optimize the parameters for the synthesis, purification, and freeze-drying of chitosan nanoparticles. We evaluated the conditions of agitation speed, anion addition time, solution pH, and chitosan and sodium tripolyphosphate concentration. RESULTS: Chitosan nanoparticles presented an average particle size of 172.8 ± 3.937 nm, PDI of 0.166 ± 0.008, and zeta potential of 25.00 ± 0.79 mV, at the concentration of 0.1% sodium tripolyphosphate and chitosan (pH 5.5), with a dripping time of 2 min at 500 rpm. The most representative factor during nanoparticle fabrication was the pH of the chitosan solution, generating significant changes in particle size and polydispersity index. The observed behavior is attributed to the possible excess of sodium tripolyphosphate during synthesis. We added the surfactants poloxamer 188 and polysorbate 80 to evaluate the stability improvement during purification (centrifugation or dialysis). These surfactants decreased coalescence between nanoparticles, especially during purification. The centrifugation increased the zeta potential to 40.8-56.2 mV values, while the dialyzed samples led to smaller particle sizes (152-184 nm). Finally, freeze-drying of the chitosan nanoparticles proceeded using two cryoprotectants, trehalose and sucrose. Both adequately protected the system during the process, and the sugar concentration depended on the purification process. CONCLUSIONS: In Conclusion, we must consider each surfactant's benefits in formulations for selecting the most suitable. Also, it is necessary to do more studies with the molecule to load. At the same time, the use of sucrose and trehalose generates adequate protection against the freeze-drying process, even at a 5% w/v concentration. However, adjusting the percentage concentration by weight must be made to work with the CS-TPP NPs purified by dialysis.

Remaining microtia tissue as a source for 3D bioprinted elastic cartilage tissue constructs, potential use for surgical microtia reconstruction.

The absence of ears in children is a global problem. An implant made of costal cartilage is the standard procedure for ear reconstruction; however, side effects such as pneumothorax, loss of thoracic cage shape, and respiratory complications have been documented. Three-dimensional (3D) printing allows the generation of biocompatible scaffolds that mimic the shape, mechanical strength, and architecture of the native extracellular matrix necessary to promote new elastic cartilage formation. We report the potential use of a 3D-bioprinted poly-ε-caprolactone (3D-PCL) auricle-shaped framework seeded with remaining human microtia chondrocytes for the development of elastic cartilage for autologous microtia ear reconstruction. An in vivo assay of the neo-tissue formed revealed the generation of a 3D pinna-shaped neo-tissue, and confirmed the formation of elastic cartilage by the presence of type II collagen and elastin with histological features and a protein composition consistent with normal elastic cartilage. According to our results, a combination of 3D-PCL auricle frameworks and autologous microtia remnant tissue generates a suitable pinna structure for autologous ear reconstruction.

Chondrogenic Potential of Human Adipose-Derived Mesenchymal Stromal Cells in Steam Sterilized Gelatin/Chitosan/Polyvinyl Alcohol Hydrogels.

Cross-linked polymer blends from natural compounds, namely gelatin (Gel), chitosan (CS), and synthetic poly (vinyl alcohol) (PVA), have received increasing scrutiny because of their versatility, biocompatibility, and ease of use for tissue engineering. Previously, Gel/CS/PVA [1:1:1] hydrogel produced via the freeze-drying process presented enhanced mechanical properties. This study aimed to investigate the biocompatibility and chondrogenic potential of a steam-sterilized Gel/CS/PVA hydrogel using differentiation of human adipose-derived mesenchymal stromal cells (AD-hMSC) and cartilage marker expression. AD-hMSC displayed fibroblast-like morphology, 90% viability, and 69% proliferative potential. Mesenchymal profiles CD73 (98.3%), CD90 (98.6%), CD105 (97.0%), CD34 (1.11%), CD45 (0.27%), HLA-DR (0.24%); as well as multilineage potential, were confirmed. Chondrogenic differentiation of AD-hMSC in monolayer revealed the formation of cartilaginous nodules composed of glycosaminoglycans after 21 days. Compared to nonstimulated cells, hMSC-derived chondrocytes shifted the expression of CD49a from 2.82% to 40.6%, CD49e from 51.4% to 92.2%, CD54 from 9.66 to 37.2%, and CD151 from 45.1% to 75.8%. When cultured onto Gel/CS/PVA hydrogel during chondrogenic stimulation, AD-hMSC changed to polygonal morphology, and chondrogenic nodules increased by day 15, six days earlier than monolayer-differentiated cells. SEM analysis showed that hMSC-derived chondrocytes adhered to the surface with extended filopodia and abundant ECM formation. Chondrogenic nodules were positive for aggrecan and type II collagen, two of the most abundant components in cartilage. This study supports the biocompatibility of AD-hMSC onto steam-sterilized GE/CS/PVA hydrogels and its improved potential for chondrocyte differentiation. Hydrogel properties were not altered after steam sterilization, which is relevant for biosafety and biomedical purposes.

Recombinant Antibodies to Face SARS-CoV-2 Syndemic.

In recent years, increasing interest has been paid to using antibody-based therapies for clinical applications. However, it is unclear whether recombinant antibodies can be combined with other scientific approaches to generate innovative solutions for mitigating severe acute respiratory syndrome coronavirus 2. In this context, the increase in this virus transmission, the number of infected people, and the interaction between social and biological processes have led to a syndemic, exacerbating the public health problem. Here, we argue about recent advances in recombinant antibody strategies and the perspective of using them to face this syndemic. Thus, the most promising methods in sample readiness, potency, and reduction of manufacturing time frame have been highlighted.

Current Status of the Therapeutic Approach for Dysmenorrhea.

Dysmenorrhea is the combination of cramps and pain associated with the menstrual period, and the symptoms affect at least 30% of women worldwide. Tolerance to symptoms depends on each person's pain threshold; however, dysmenorrhea seriously affects daily activities and chronically reduces the quality of life. Some dysmenorrhea cases even require hospitalization due to unbearable symptoms of severe pain. Dysmenorrhea is an underestimated affectation and remains even in different first-world countries as a taboo subject, promoted by the establishment of an apparent policy of gender equality. A person with primary or secondary dysmenorrhea requires medical assistance in choosing the best treatment and an integral approach. This review intends to demonstrate the impact of dysmenorrhea on quality of life. We describe the pathophysiology of this disorder from a molecular point of view and perform a comprehensive compilation and analysis of the most critical findings in the therapeutic management of dysmenorrhea. Likewise, we propose an interdisciplinary approach to the phenomenon of dysmenorrhea at the cellular level in a concise way and the botanical, pharmacological, and medical applications for its management. Since dysmenorrhea symptoms can vary between individuals, medical treatment cannot be generalized and depends on each patient. Therefore, we hypothesized that a suitable strategy could result from the combination of pharmacological therapy aided by a non-pharmacological approach.

Inhibition of proliferation, migration, and adhesion of skin fibroblasts by enzymatic poly(gallic acid) grafted with L-Arginine, migration, and adhesion of skin fibroblasts by enzymatic poly(gallic acid) grafted with L-Arginine.

Psoriasis and atopic dermatitis (AD) are characterized by enhanced skin inflammation, which results in hyperproliferation and the recruitment of immune cells into the skin. For that reason, it is needed a chemical capable to reduce cell proliferation and the recruitment of cells. The search for new molecules for therapeutic skin treatment mainly focuses on the antioxidant and anti-inflammatory properties, highlighting the rheological properties of polymeric polypeptides. We studied L-arginine (L-Arg) grafted (-g-) to enzymatic poly(gallic acid) (PGAL). The latter is a multiradical antioxidant with greater properties and thermal stability. The derivative was enzymatically polymerized in an innocuous procedure. The poly(gallic acid)-g-L-Arg molecule (PGAL-g-L-Arg) inhibits bacterial strains which also have been involved in the progression of psoriasis and AD. However, it is important to analyze their biological effect on skin cells. The cell viability was analyzed by calcein/ethidium homodimer assays and crystal violet. The proliferation and cell attachment were determined by a curve of time and quantitation of the optical density of crystal violet. To analyze the cell migration a wound-healing assay was performed. This synthesis demonstrates that it is not cytotoxic at high concentrations (250 µg/mL). We observed a decrease in the proliferation, migration, and adhesion of dermal fibroblasts in vitro but the compound could not avoid the increase of reactive oxygen species in the cell. Based on our findings, PGAL-g-L-Arg is a promising candidate for treating skin diseases such as psoriasis and AD where decreasing the proliferation and cell migration could help to avoid inflammation.

Recent advances in modified poly (lactic acid) as tissue engineering materials.

As an emerging science, tissue engineering and regenerative medicine focus on developing materials to replace, restore or improve organs or tissues and enhancing the cellular capacity to proliferate, migrate and differentiate into different cell types and specific tissues. Renewable resources have been used to develop new materials, resulting in attempts to produce various environmentally friendly biomaterials. Poly (lactic acid) (PLA) is a biopolymer known to be biodegradable and it is produced from the fermentation of carbohydrates. PLA can be combined with other polymers to produce new biomaterials with suitable physicochemical properties for tissue engineering applications. Here, the advances in modified PLA as tissue engineering materials are discussed in light of its drawbacks, such as biological inertness, low cell adhesion, and low degradation rate, and the efforts conducted to address these challenges toward the design of new enhanced alternative biomaterials.

Alteration of the blood-brain barrier by COVID-19 and its implication in the permeation of drugs into the brain.

Diverse neurological symptoms have been reported in patients with SARS-CoV-2 disease (COVID-19), including stroke, ataxia, meningitis, encephalitis, and cognitive impairment. These alterations can cause serious sequelae or death and are associated with the entry of SARS-CoV-2 into the Central Nervous System (CNS). This mini-review discusses the main proposed mechanisms by which SARS-CoV-2 interacts with the blood-brain barrier (BBB) and its involvement in the passage of drugs into the CNS. We performed a search in PubMed with the terms "COVID-19" or "SARS-CoV-2" and "blood-brain barrier injury" or "brain injury" from the year 2019 to 2022. We found proposed evidence that SARS-CoV-2 infects neurovascular cells and increases BBB permeability by increasing the expression of matrix metalloproteinase-9 that degrades type IV collagen in the basement membrane and through activating RhoA, which induces restructuring of the cytoskeleton and alters the integrity of the barrier. The breakdown of the BBB triggers a severe inflammatory response, causing the cytokine storm (release of IL-1ß, IL-6, TNF-α, etc.) characteristic of the severe phase of COVID-19, which includes the recruitment of macrophages and lymphocytes and the activation of astrocytes and microglia. We conclude that the increased permeability of the BBB would allow the passage of drugs that would not reach the brain in a normal physiological state, thus enhancing certain drugs' beneficial or adverse effects. We hope this article will encourage research on the impact of drugs on patients with COVID-19 and recovered patients with sequelae, focusing mainly on possible dose adjustments and changes in pharmacokinetic parameters.

Combined use of novel chitosan-grafted N-hydroxyethyl acrylamide polyurethane and human dermal fibroblasts as a construct for in vitro-engineered skin.

A rich plethora of information about grafted chitosan (CS) for medical use has been reported. The capability of CS-grafted poly(N-hydroxyethyl acrylamide) (CS-g-PHEAA) to support human dermal fibroblasts (HDFs) in vitro has been proven. However, CS-grafted copolymers lack good stiffness and the characteristic microstructure of a cellular matrix. In addition, whether CS-g-PHEAA can be used to prepare a scaffold with a suitable morphology and mechanical properties for skin tissue engineering (STE) is unclear. This study aimed to show for the first time that step-growth polymerizations can be used to obtain polyurethane (PU) platforms of CS-g-PHEAA, which can also have enhanced microhardness and be suitable for in vitro cell culture. The PU prepolymers were prepared from grafted CS, polyethylene glycol, and 1,6-hexamethylene diisocyanate. The results proved that a poly(saccharide-urethane) [(CS-g-PHEAA)-PU] could be successfully synthesized with a more suitable microarchitecture, thermal properties, and topology than CS-PU for the dynamic culturing of fibroblasts. Cytotoxicity, proliferation, histological and immunophenotype assessments revealed significantly higher biocompatibility and cell proliferation of the derivative concerning the controls. Cells cultured on (CS-g-PHEAA)-PU displayed a quiescent state compared to those cultured on CS-PU, which showed an activated phenotype. These findings may be critical factors in future studies establishing wound dressing models.

Discovering the effect of solvents on poly(2-aminoethyl methacrylate) grafting onto chitosan for an in vitro skin model.

The design of controlled grafting copolymers is critical in synthesizing effective artificial cellular matrices because of their regulatory role in cellular behavior. However, it is unclear whether poly(2-aminoethyl methacrylate) grafted onto chitosan generated by gamma-radiation-induced graft polymerization in different solvents can influence the physicochemical properties and biotech applicability of the copolymer. This work aims to demonstrate for the first time the effect of various solvents on the synthesis, properties, and biological performance of grafted chitosan using the simultaneous irradiation method. The results proved that the solvent is one of the critical factors affecting the properties of the modified polysaccharide. The degree of grafting showed a solvent-dependent profile. Hexane presented utmost importance concerning the degree of grafting. Ethyl acetate showed the best results in grafting extent and human dermal fibroblast growth. These findings indicate that proper solvent selection determines the possible copolymer use for in vitro engineered skin substitute models.

A poly (saccharide-ester-urethane) scaffold for mammalian cell growth.

Chitosan and poly(3-hydroxybutyrate) are non-toxic, biodegradable, and biocompatible polymers extensively used in regenerative medicine. However, it is unknown whether the chemical combination of these polymers can produce a biomaterial that induces an appropriate cellular response in vitro in mammalian cells. This study aimed to test the ability of a novel salt-leached polyurethane scaffold of chitosan grafted with poly(3-hydroxybutyrate) to support the growth of three mammalian cell lines of different origin: a) HEK-293 cells, b) i28 mouse myoblasts, and c) human dermal fibroblasts. The viability of the cells was assessed by either evaluation of their capacity to maintain the expression of the green fluorescent protein by adenoviral transduction or by esterase activity and plasma membrane integrity. The results indicated that the three cell lines attached well to the scaffold; however, when i28 cells were induced to differentiate, they did not produce morphologically distinct myofibers, and cell growth ceased. In conclusion, the findings reveal that, altogether, these observations suggest that this foam scaffold supports cell growth and proliferation but may not apply to all cell types. Hence, one crucial question yet to be resolved is a poly (saccharide-ester-urethane) derivative with a nano-topography that elicits a similar cellular response for different biological environments.

Curcumin for parkinson´s disease: potential therapeutic effects, molecular mechanisms, and nanoformulations to enhance its efficacy.

Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders worldwide. It is caused by the degeneration of dopaminergic neurons from the substantia nigra pars compacta. This neuronal loss causes the dopamine deficiency that leads to a series of functional changes within the basal ganglia, producing motor control abnormalities. L-DOPA is considered the gold standard for PD treatment, and it may alleviate its clinical manifestations for some time. However, its prolonged administration produces tolerance and several severe side effects, including dyskinesias and gastrointestinal disorders. Thus, there is an urgent need to find effective medications, and current trends have proposed some natural products as emerging options for this purpose. Concerning this, curcumin represents a promising bioactive compound with high therapeutic potential. Diverse studies in cellular and animal models have suggested that curcumin could be employed for the treatment of PD. Therefore, the objective of this narrative mini-review is to present an overview of the possible therapeutic effects of curcumin and the subjacent molecular mechanisms. Moreover, we describe several possible nanocarrier-based approaches to improve the bioavailability of curcumin and enhance its biological activity.

Development of films from natural sources for infections during wound healing.

The skin is the largest organ in the human body, and due to its barrier function, it is susceptible to multiple injuries. The appearance of infections during the wound healing process is a complication that represents a formidable hospital challenge. The presence of opportunistic bacteria with sophisticated resistance mechanisms is difficult to eradicate and compromises patients' lives. Therefore, the search for new efficacious treatments from natural sources that prevent and counteract infections, in addition to promoting the healing process, has increased in recent years. In this respect, films with the capability to protect wounds and release drugs are the presentation that predominates commercially in the hospital environment. Those films can offer several mechanical advantages such as physical protection to prevent opportunistic bacteria's entry, regulation of gas exchange, and capture of exudate through a swelling process. Wound dressings are generally curative materials easily adaptable to different anatomical regions, with high strength and elasticity, and some are even bioabsorbable. Additionally, the components of the films can actively participate in promoting the healing process. Even more, the film can be made up of carriers with other active participants to prevent and eradicate infections. Therefore, the extensive versatility, practicality, and usefulness of films from natural sources to address infectious processes during wound healing are relevant and recurrent themes. This work presents an analysis of the state-of-the-art of films with natural products focused on preventing and eradicating infections in wound healing.

Development of a guar gum film with lysine clonixinate for periodontal treatments.

Periodontal pain is a public health problem derived from different conditions, including periodontal diseases, prosthetic complications, and even extractions performed by dentist. There are various treatments to control acute dental pain, being the administration of analgesics, such as Lysine Clonixinate (LC), a common practice. Unfortunately, higher and repeated dosages are usually required. The purpose of this work was to develop a prolonged release pharmaceutical form as an alternative treatment for dental pain. Hence, we conceived a film based on guar gum and loaded different concentrations of LC. We evaluated the film's appearance, brittleness, strength, and flexibility, and then chose one formulation for adequate characteristics. Subsequently, we assessed the morphology, thermal behavior, and swelling properties of the films (LC-free and -loaded). Finally, we performed the release studies of LC from the films in vitro using a simulated saliva medium and employed several mathematical models to evaluate the release kinetics. Guar gum is a natural polymer obtained from the endosperm of Cyamopsis tetragonolobus that presents properties such as biosafety, biocompatibility, and biodegradability. Thus, it represents a potential excipient for use in pharmaceutical formulations. Moreover, our results revealed that the LC-loaded film presented a high adherence, suitable swelling behavior, high LC content, and a prolonged drug release. Therefore, the LC-loaded film may be considered a potential option to be applied as an alternative to treat dental pain.

Development of a xanthan gum film for the possible treatment of vaginal infections.

Bacterial vaginosis is a vaginal infection that affects 60% of women of reproductive age worldwide. It is mainly caused by the bacterium Gardnerella vaginalis and is a factor that increases the probability of getting sexually transmitted diseases. We aimed to develop a new pharmaceutical form for the treatment of vaginal infections. We employed the solving-casting method to fabricate a polymeric film with Xanthan gum, a natural polymer produced by the bacterium Xanthomonas campestris, and metronidazole, one of the most commonly used drugs for vaginal infections. In order to characterize the film, we measured pH, dose uniformity, dissolution profile, and the percentage of swelling. Moreover, we performed a thermogravimetric analysis and scanning electron microscopy. The results demonstrated a pH suitable for vaginal application and uniform distribution of the drug in the film. Also, the formulation exhibited a high percentage of swelling and a slow release of the drug in a simulated vaginal fluid medium. All these attributes indicated that the manufactured film has ideal characteristics to be used and administered vaginally. It could be an excellent alternative to treat bacterial vaginosis and also improve user adherence.

Physicochemical and biological characterization of a xanthan gum-polyvinylpyrrolidone hydrogel obtained by gamma irradiation.

Xanthan gum (XG) and polyvinylpyrrolidone (PVP) are two polymers with low toxicity, high biocompatibility, biodegradability, and high hydrophilicity, making them promising candidates for multiple medical aspects. The present work aimed to synthesize a hydrogel from a mixture of XG and PVP and crosslinked by gamma irradiation. We assessed the hydrogel through a series of physicochemical (FT-IR, TGA, SEM, and percentage of swelling) and biological (stability of the hydrogel in cell culture medium) methods that allowed to determine its applicability. The structural evaluation by infrared spectrum demonstrated that a crosslinked hydrogel was obtained from the combination of polymers. The calorimetric test and swelling percentage confirmed the formation of the bonds responsible for the crosslinked structure. The calorimetric test evidenced that the hydrogel was resistant to decomposition in contrast to non- irradiated material. The determination of the swelling degree showed constant behavior over time, indicating a structure resistant to hydrolysis. This phenomenon also occurred during the test of stability in a cell culture medium. Additionally, microscopic analysis of the sample revealed an amorphous matrix with the presence of porosity. Thus, the findings reveal the synthesis of a novel material that has desirable attributes for its potential application in pharmaceutical and biomedical areas.