Recent progress of polymeric microneedle-assisted long-acting transdermal drug delivery

Transdermal Semaglutide Administration in Mice: Reduces Body Weight by Suppressing Appetite and Enhancing Metabolic Rate

BACKGROUND

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that shows significant efficacy in treating obesity. However, its associated side effects, including poor patient compliance and gastrointestinal inflammation, are concerning and may be largely attributed to its administration methods (e.g., injection vs. oral) and the pronounced fluctuations in systemic drug concentrations. To address these challenges, we investigated an innovative drug delivery system (Transdermal Drug Delivery System, TDDS) designed to maintain therapeutic efficacy while improving patient adherence.

RESULTS

Both transdermal and injection treatments of semaglutide decreased body weight, carcass weight, blood glucose, and triglyceride levels in male mice compared with the vehicle-treated control group. In addition, transdermal semaglutide in mice reduced the expression of feeding neuropeptides and the mass of the digestive tract, but increased brown adipose tissue (BAT) mass, metabolic rate, and physical activity, compared with the semaglutide injection group. Additionally, transdermal semaglutide had anxiolytic effects on behavior and did not alter tissue pathology in mice.

CONCLUSION

Compared with the injection paradigm, transdermal semaglutide treatment achieved superior weight loss results in two possible ways: It may reduce energy intake by decreasing the expression of feeding neuropeptides and reducing the weight of the digestive tract. It may also facilitate energy expenditure by enhancing physical activity and increasing BAT mass to boost the metabolic rate. Transdermal semaglutide treatment also has an anxiolytic effect on behavior. Together, our data suggest that TDDS treatment of GLP-1RA may have superior clinical safety and sustainability, providing a novel, efficient, and low-risk obesity treatment.

A review on microneedle patch as a delivery system for proteins/peptides and their applications in transdermal inflammation suppression

Transdermal delivery is one of the most recent modes of administration studied due to several shortfalls observed for intra-venous, and oral drug administrations. Among, microneedle-based transdermal delivery is the popular choice due to non-invasive procedure and minimal toxicological effects. Microneedle devices consist of micron scaled needle patch entrapped with the target specific drug molecules. Due to body's immune response and occasional pathogen attack, various inflammatory diseases are developed such as psoriasis, dermatitis, rashes, rheumatoid arthritis, gouty arthritis, and fibrosis. These inflammatory conditions can be treated by microneedle assisted transdermal delivery. Moreover, for localized suppression of pain and inflammation, various therapeutic peptides and proteins have been investigated. Although, these therapeutic agents can show reduced activity and undergo enzymatic degradation when administered orally or intra-venously. Hence, a microneedle-based delivery system can be used as an effective way to localize these peptides/proteins and reduce the inflammation. Herein, this review includes various microneedle fabrication methods for enhancing drug delivery for suppression of inflammation. Moreover, recent development in microneedle devices of peptide and protein delivery applications are discoursed. At last, future scope and challenges endured for preparing an efficient microneedle patch for peptide and protein delivery are also elaborated.

Polymeric microneedle advancements in macromolecule drug delivery: current trends, challenges, and future perspectives

Microneedles (MNs) offer a transformative solution for delivering macromolecules, including proteins, RNA, and peptides. These are critical in treating complex diseases but face significant challenges such as immunogenicity, poor stability, high molecular weight, and delivery efficiency. Unlike conventional methods, MNs efficiently bypass biological barriers like the stratum corneum, enabling precise and minimally invasive transdermal drug delivery. This review explores various MN types such as solid, coated, hollow, hydrogel-forming, and dissolving and their therapeutic applications in cancer immunotherapy, diabetes management, and osteoporosis treatment. For instance, dissolving MNs have been employed for transdermal insulin delivery, enhancing patient compliance and therapeutic outcomes. Similarly, hydrogel MNs have shown promise in sustained drug release for immunotherapy applications. By addressing cost and scalability issues, polymeric MNs demonstrate significant potential for clinical translation, paving the way for innovations in macromolecule delivery, diagnostics, and personalised medicine. This review underscores the pivotal role of MNs in redefining drug delivery systems, offering improved efficacy, patient comfort, and accessibility.

Microneedle-Assisted Delivery of Curcumin: Evaluating the Effects of Needle Length and Formulation

Dermal drug delivery presents a significant challenge for poorly soluble active compounds like curcumin, which often struggle to penetrate the skin barrier effectively. In this study, the dermal penetration efficacy of curcumin nanocrystals and bulk suspensions when applied to skin using microneedles of varying lengths-0.25 mm, 0.5 mm, and 1.0 mm-was investigated in an ex vivo porcine ear model. The findings revealed that all formulations, in conjunction with microneedle application, facilitated transepidermal penetration; however, the combination of microneedles and curcumin nanocrystals demonstrated the highest efficacy. Notably, the 1.0 mm microneedle length provided optimal penetration, significantly enhancing curcumin delivery compared with bulk suspensions alone. Additionally, even the use of 0.25 mm microneedles resulted in a high level of efficiency, indicating that shorter microneedles can still effectively facilitate drug delivery. Overall, this study underscores the potential of microneedle technology in improving the transepidermal absorption of poorly soluble actives like curcumin, suggesting that the integration of nanocrystals with microneedles could enhance the therapeutic effects of topical curcumin applications.

Cellular Interactions and Biological Effects of Silk Fibroin: Implications for Tissue Engineering and Regenerative Medicine

Silk fibroin (SF), the core structural protein derived from Bombyx mori silk, is extensively employed in tissue engineering and regenerative medicine due to its exceptional mechanical properties, favorable biocompatibility, tunable biodegradability, and versatile processing capabilities. Despite these advantages, current research predominantly focuses on SF biomaterials as structural scaffolds or drug carriers, often overlooking their potential role in modulating cellular behavior and tissue regeneration. This review aims to present a comprehensive overview of the inherent biological effects of SF biomaterials, independent of any exogenous biomolecules, and their implications for various tissue regeneration. It will cover in vitro cellular interactions of SF with various cell types, including stem cells and functional tissue cells such as osteoblasts, chondrocytes, keratinocytes, endothelial cells, fibroblasts, and epithelial cells. Moreover, it will summarize in vivo immune responses, cellular responses, and tissue regeneration following SF implantation, specifically focusing on vascular, bone, skin, cartilage, ocular, and tendon/ligament regeneration. Furthermore, it will address current limitations and future perspectives in the design of bioactive SF biomaterials. A comprehensive understanding of these cellular interactions and the biological effects of SF is crucial for predicting regenerative outcomes with precision and for designing SF-based biomaterials tailored to specific properties, enabling broader applications in regenerative medicine.

Current multi-scale biomaterials for tissue regeneration following spinal cord injury

Spinal cord injury (SCI) may cause loss of motor and sensory function, autonomic dysfunction, and thus disrupt the quality of life of patients, leading to severe disability and significant psychological, social, and economic burden. At present, existing therapy for SCI have limited ability to promote neural function recovery, and there is an urgent need to develop innovative regenerative approaches to repair SCI. Biomaterials have become a promising strategy to promote the regeneration and repair of damaged nerve tissue after SCI. Biomaterials can provide support for nerve tissue by filling cavities, and improve local inflammatory responses and reshape extracellular matrix structures through unique biochemical properties to create the optimal microenvironment at the SCI site, thereby promoting neurogenesis and reconnecting damaged spinal cord tissue. Considering the importance of biomaterials in repairing SCI, this article reviews the latest progress of multi-scale biomaterials in SCI treatment and tissue regeneration, and evaluates the relevant technologies for manufacturing biomaterials.