Microneedle (MNs) technology is a recent advancement in biomedical science across the globe. The current limitations of drug delivery, like poor absorption, low bioavailability, inadequate skin permeation, and poor biodistribution, can be overcome by MN-based drug delivery. Nanotechnology made significant changes in fabrication techniques for microneedles (MNs) and design shifted from conventional to novel, using various types of natural and synthetic materials and their combinations. Nowadays, MNs technology has gained popularity worldwide in biomedical research and drug delivery technology due to its multifaceted and broad-spectrum applications. This review broadly discusses MN’s types, fabrication methods, composition, characterization, applications, recent advancements, and global intellectual scenarios.

Temperature-induced, rapid changes in the viscosity and reproducible 3-D structure formation makes thermos-sensitive hydrogels an ideal delivery system to act as a cell scaffold or a drug reservoir. Moreover, the hydrogels’ minimum invasiveness, high biocompatibility, and facile elimination from the body have gathered a lot of attention from researchers. This review article attempts to present a complete picture of the exhaustive arena, including the synthesis, mechanism, and biomedical applications of thermosensitive hydrogels. A special section on intellectual property and marketed products tries to shed some light on the commercial potential of thermosensitive hydrogels.

Polymeric nanocomposites have been outstanding functional materials and have garnered immense attention as sustainable materials to address multi-disciplinary problems. MXenes have emerged as a newer class of 2D materials that produce metallic conductivity upon interaction with hydrophilic species, and their delamination affords monolayer nanoplatelets of a thickness of about one nm and a side size in the micrometer range. Delaminated MXene has a high aspect ratio, making it an alluring nanofiller for multifunctional polymer nanocomposites. Herein, we have classified and discussed the structure, properties and application of major polysaccharide-based electroactive hydrogels (hyaluronic acid (HA), alginate sodium (SA), chitosan (CS) and cellulose) in biomedical applications, starting with the brief historical account of MXene’s development followed by successive discussions on the synthesis methods, structures and properties of nanocomposites encompassing polysaccharides and MXenes, including their biomedical applications, cytotoxicity and biocompatibility aspects. Finally, the MXenes and their utility in the biomedical arena is deliberated with an eye on potential opportunities and challenges anticipated for them in the future, thus promoting their multifaceted applications.

A key challenge of HIV treatment with multiple antiretroviral drugs is patient adherence. Thus, there is an urgent need for long-acting depot systems for delivering drugs over an extended duration. Although the parenteral route is preferred for depot systems, it is associated with obvious drawbacks, such as painful injections, potentially-contaminated sharps waste, and the necessity of trained healthcare personnel for administration. Amongst a small number of alternatives in development microneedles are versatile delivery systems enabling systemic drug delivery and potentially improving patient adherence due to their capacity for self-administration. We have developed dissolving microneedle (DMNs) embedded with etravirine nanosuspension (ETR NS) as a long-acting HIV therapy to improve patient adherence. The ETR NS prepared by sonoprecipitation yielded particle sizes of 764 ± 96.2 nm, polydispersity indices of of 0.23 ± 0.02, and zeta potentials of -19.75 ± 0.55 mV. The DMNs loaded with ETR NS demonstrated 12.84 ± 1.33% ETR deposition in ex-vivo neonatal porcine skin after 6 h application. In in vivo rat pharmacokinetic studies, the Cmax exhibited by DMNs loaded with ETR powder and ETR NS were 158 ± 10 ng/mL and 177 ± 30 ng/mL, respectively. DMN groups revealed a higher t1/2, Tmax, and mean residence time compared to intravenous ETR solutions, suggesting the long-acting potential of etravirine delivered intradermally using DMNs.