There is ongoing research for biomedical applications of polyvinyl alcohol (PVA)-based hydrogels; however, the execution of this has not yet been achieved at an appropriate level for commercialization. Advanced perception is necessary for the design and synthesis of suitable materials, such as PVA-based hydrogel for biomedical applications. Among polymers, PVA-based hydrogel has drawn great interest in biomedical applications owing to their attractive potential with characteristics such as good biocompatibility, great mechanical strength, and apposite water content. By designing the suitable synthesis approach and investigating the hydrogel structure, PVA-based hydrogels can attain superb cytocompatibility, flexibility, and antimicrobial activities, signifying that it is a good candidate for tissue engineering and regenerative medicine, drug delivery, wound dressing, contact lenses, and other fields. In this review, we highlight the current progresses on the synthesis of PVA-based hydrogels for biomedical applications explaining their diverse usage across a variety of areas. We explain numerous synthesis techniques and related phenomena for biomedical applications based on these materials. This review may stipulate a wide reference for future acumens of PVA-based hydrogel materials for their extensive applications in biomedical fields.

Poly(vinyl alcohol) (PVA)–ZnS composite films were prepared by varying the composition of PVA ranging from 1–5 wt % through a simple solvent casting method. The photocatalytic enactment of the composites was evaluated along with the investigations of their photoluminescence (PL), optical transparency, morphology, and thermal properties. The firm interaction between the ZnS and PVA was confirmed by Fourier transform infrared, UV–vis, and PL spectroscopies. PVA–ZnS composites showed enhanced luminescence property than PVA. The composites exhibited very good optical transparency regardless of the amount of PVA addition. The thermogravimetric analysis data indeed exhibited better thermal stability of the composites. The glass transition temperature (T_g), melting temperature (T_m), enthalpy of melting (ΔH_m), and crystallinity were evaluated for such composites. The composites demonstrated morphological variations depending on the amount of PVA addition, although the particle size of ZnS remained similar in the nanometer range (50–120 nm) for all composite samples. The prepared composite films exhibited superior photocatalytic performance in the degradation of methylene blue compared with the bare ZnS and PVA. This study may give a new insight into the fabrication of PVA–ZnS photocatalysts for the treatment of organic pollutants.

Achieving the ideal replacement for robust biological tissues requires biocompatible materials with a nuanced blend of characteristics, including organ specific toughness, durability, self-repairing capability, and a well-defined structure. Hydrogels, structured with high water containing 3D-crosslinked polymeric networks, present a promising avenue in biomedical applications due to their close resemblance to natural tissues. However, their mechanical performance often falls short, limiting their clinical applications. Recent research has been focused on developing biocompatible hydrogel materials for therapeutic applications. Recent advancements have spurred researchers to develop biocompatible hydrogels having acceptable mechanical toughness. While it is now possible to tailor the mechanical properties of synthetic gels to mimic those of natural tissues, critical aspects such as biocompatibility and crosslinking strategies are frequently neglected. This review scrutinizes the structural and crosslinking techniques designed to improve the toughness of hydrogels, focusing especially on innovative efforts to integrate these enhancements into natural-based hydrogels. By thoroughly examining these methodologies, the review sheds light on the complexities of strengthening hydrogels for biomedical applications and will propose valuable insights for the development of next-generation tissue substitutes.

A Simple UV-spectrophotometric Method for the Determination of Vitamin C Content in Various Fruits and Vegetables at Sylhet Area in Bangladesh

Several kinds of acrylic-acid-grafted-starch (starch/AAc) hydrogels were prepared at room temperature (27°C) by applying 5, 10, 15, 20, and 25 kGy of gamma radiation to 15% AAc aqueous solutions containing 5, 7.5, and 15% of starch. With increment of the radiation dose, gel fraction became higher and attained the maximum (96.5%) at 15 kGy, above which the fraction got lowered. On the other hand, the gel fraction monotonically increased with the starch content. Swelling ratios were lower for the starch/AAc hydrogels prepared with higher gamma-ray doses and so with larger starch contents. Significant promotions of the swelling ratios were demonstrated by hydrolysis with NaOH:13632±10%for 15 kGy radiation-dosed [5% starch/15% AAc] hydrogel, while the maximum swelling ratio was ~200% for those without the treatment. The authors further investigated the availability of the starch/AAc hydrogel as an adsorbent recovering dye waste from the industrial effluents by adopting methylene blue as a model material; the hydrogels showed high dye-capturing coefficients which increase with the starch ratio. The optimum dye adsorption was found to be 576 mg per g of the hydrogel having 7.5 starch and 15% AAc composition. Two kinetic models, (i) pseudo-first-order and (ii) pseudo-second-order kinetic models, were applied to test the experimental data. The latter provided the best correlation of the experimental data compared to the pseudo-first-order model.