Nanogels are polymer-based, crosslinked hydrogel particles on the nanometer scale. Nanogels developed from synthetic and natural polymers have gathered a great deal of attention in industry and scientific society due to having an increased surface area, softness, flexibility, absorption, and drug loading ability, as well as their mimicking the environment of a tissue. Nanogels having biocompatibility, nontoxic and biodegradable properties with exceptional design, fabrication, and coating facilities may be used for a variety of different biomedical applications, such as drug delivery and therapy, tissue engineering, and bioimaging. Nanogels fabricated by chemical crosslinking and physical self-assembly displayed the ability to encapsulate therapeutics, including hydrophobic, hydrophilic, and small molecules, proteins, peptides, RNA and DNA sequences, and even ultrasmall nanoparticles within their three-dimensional polymer networks. One of the many drug delivery methods being investigated as a practical option for targeted delivery of drugs for cancer treatment is nanogels. The delivery of DNA and anticancer drugs like doxorubicin, epirubicin, and paclitaxel has been eased by polymeric nanogels. Stimuli-responsive PEGylated nanogels have been reported as smart nanomedicines for cancer diagnostics and therapy. Another promising biomedical application of nanogels is wound healing. Wounds are injuries to living tissue caused by a cut, blow, or other impact. There are numerous nanogels having different polymer compositions that have been reported to enhance the wound healing process, such as hyaluronan, poly-L-lysine, and berberine. When antimicrobial resistance is present, wound healing becomes a complicated process. Researchers are looking for novel alternative approaches, as foreign microorganisms in wounds are becoming resistant to antibiotics. Silver nanogels have been reported as a popular antimicrobial choice, as silver has been used as an antimicrobial throughout a prolonged period. Lignin-incorporated nanogels and lidocaine nanogels have also been reported as an antioxidant wound-dressing material that can aid in wound healing. In this review, we will summarize recent progress in biomedical applications for various nanogels, with a prime focus on cancer and wound healing.

Cell culture in two dimensions has been the main instrument in cellular and molecular biology. But there are limitations to two-dimensional culture when it comes to tissue engineering and in vivo reproduction. Tissue engineering technology enabled the creation of biomedical scaffolds, which are mostly utilized to biofabricate different artificial human organs. Tissue architecture that encourage cell proliferation can be produced using direct bioprinting technology. The development of bioinks for 3D bioprinting is consistently seen as a problem in the domains of biofabrication and tissue engineering. This study aimed to determine if Fibroblasts and Keratinocytes could grow on hydrogel scaffolds as efficiently as they can in the culture plates. Melanocytes were co-cultured, and the production of melanin was assessed in a two- and three-dimensional culture system. Scaffolds were fabricated using 8% alginate and 6% gelatin and 3D-printed using a cell link printer. FTIR was used to determine the precise composition of the gels. SEM analysis was performed for the cells present in gel and the topology of the cells. In addition, 8% alginate and 6% alginate gel scaffolds were analyzed for swelling and degradation over time in the cell growth medium and PBS. Furthermore, a gene expression study of cell cultures on scaffolds was performed through qPCR. A live/dead assay was performed to determine cell viability for cells grown on scaffolds for 7, 14, and 21 days. Most of the cells were shown to be viable, similar to the control cells grown on a plate. The findings from the SEM showed that cells were grown on the gel surface, remained viable even after 21 days, and displayed circular cells stacked three-dimensionally on the gel surface in the 3D scaffold. The MTT assay was performed to check the viability of cells cultured on a 3D-printed scaffold for 1, 5, and 15 days. We observed about 40% viable cells after 15 days, as shown by the MTT assay. Furthermore, a co-culture study with Melanocyte showed an increased production of melanin in a 3D culture as compared to a 2D culture. Our findings suggest that an alginate and gelatin polymer can be used as a cellular matrix for epithelial cell culture. Further, in vivo and ex vivo experiments are needed to validate the results for future applications in tissue engineering for wound healing and other tissue engineering domains.