Introduction of a model of skin lesions on rats and testing of dissolving microneedles containing 5-aminolevulinic acid

Advances in Intelligent Stimuli-Responsive Microneedle for Biomedical Applications

Microneedles (MNs) are a new type of drug delivery method that can be regarded as an alternative to traditional transdermal drug delivery systems. Recently, MNs have attracted widespread attention for their advantages of effectiveness, safety, and painlessness. However, the functionality of traditional MNs is too monotonous and limits their application. To improve the efficiency of disease treatment and diagnosis by combining the advantages of MNs, the concept of intelligent stimulus-responsive MNs is proposed. Intelligent stimuli-responsive MNs can exhibit unique biomedical functions according to the internal and external environment changes. This review discusses the classification and principles of intelligent stimuli-responsive MNs, such as magnet, temperature, light, electricity, reactive oxygen species, pH, glucose, and protein. This review also highlights examples of intelligent stimuli-responsive MNs for biomedical applications, such as on-demand drug delivery, tissue repair, bioimaging, detection and monitoring, and photothermal therapy. These intelligent stimuli-responsive MNs offer the advantages of high biocompatibility, targeted therapy, selective detection, and precision treatment. Finally, the prospects and challenges for the application of intelligent stimuli-responsive MNs are discussed.

Microneedle-mediated treatment for superficial tumors by combining multiple strategies

Superficial tumors are still challenging to overcome due to the high risk and toxicity of surgery and conventional chemotherapy. Microneedles (MNs) are widely used in the treatment of superficial skin tumors (SST) due to the high penetration rate of the stratum corneum (SC), excellent biocompatibility, simple preparation process, high patient compliance, and minimal invasion. Most importantly, MNs can provide not only efficient and rarely painful delivery carriers, but also combine multi-model strategies with photothermal therapy (PTT), immunotherapy, and gene therapy for synergistic efficacy. To promote an in-depth understanding of their superiorities, this paper systematically summarized the latest application progress of MNs in the treatment of SST by delivering various types of photosensitizers, immune signal molecules, genes, and chemotherapy drugs. Just as important, the advantages, limitations, and drug release mechanisms of MNs based on different materials are introduced in the paper. In addition, the application of MN technology to clinical practice is the ultimate goal of all the work. The obstacles and possible difficulties in expanding the production of MNs and achieving clinical transformation are briefly discussed in this paper. To be anticipated, our work will provide new insights into the precise and rarely painful treatment of SST in the future.

Enhanced skin drug delivery using dissolving microneedles: a potential approach for the management of skin disorders

INTRODUCTION

For decades, finding effective long-term or disease-modifying treatments for skin disorders has been a major focus of scientists. The conventional drug delivery systems showed poor efficacy with high doses and are associated with side effects, which lead to challenges in adherence to therapy. Therefore, to overcome the limitations of conventional drug delivery systems, drug delivery research has focused on topical, transdermal, and intradermal drug delivery systems. Among all, the dissolving microneedles have gained attention with a new range of advantages of drug delivery in skin disorders such as breaching skin barriers with minimal discomfort and its simplicity of application to the skin, which allows patients to administer it themselves.

AREAS COVERED

This review highlighted the insights into dissolving microneedles for different skin disorders in detail. Additionally, it also provides evidence for its effective utilization in the treatment of various skin disorders. The clinical trial status and patents for dissolving microneedles for the management of skin disorders are also covered.

EXPERT OPINION

The current review on dissolving microneedles for skin drug delivery is accentuating the breakthroughs achieved so far in the management of skin disorders. The output of the discussed case studies anticipated that dissolving microneedles can be a novel drug delivery strategy for the long-term treatment of skin disorders.

Anti-inflammatory action of geniposide promotes wound healing in diabetic rats

CONTEXT

As a major active iridoid glycoside from Gardenia jasminoides J. Ellis (Rubiaceae), geniposide possesses various pharmacological activities, including anti-platelet aggregation and anti-inflammatory action.

OBJECTIVES

This study explores the effect of geniposide in diabetic wound model by anti-inflammatory action.

MATERIALS AND METHODS

Diabetic rodent model in Wistar rats was induced by streptozotocin combined with high-fat feed. The selected rats were divided into control group, the diabetic model group and geniposide subgroups (200, 400 and 500 mg/kg), and orally administrated once daily with saline or geniposide. Wound area and histochemical indicators were measured on day 7 after continuous administration, to assess lesion retraction, inflammatory cells and fibroblasts.

RESULTS

Geniposide notably enhanced lesion retraction by 1.06-1.84 times on day 7 after surgical onset in diabetic rats (p < 0.05). In the pathological experiment by HE staining, geniposide significantly reduced inflammatory cell infiltration and proliferation of fibroblasts in the central lesion regions. In diabetic rats treated with geniposide, the levels of pro-inflammatory factors (tumour necrosis factor-α (TNF-α), interleukin-1β (IL-1β)) and IL-6 were significantly reduced (p < 0.05), followed with the increment of IL-10 in a dose-dependent manner. The IC₅₀ of geniposide on TNF-α, IL-1β and IL-6 could be calculated as 1.36, 1.02 and 1.23 g/kg, respectively. It assumed that geniposide-induced IL-10 expression contributed to inhibiting the expression of pro-inflammatory factors.

DISCUSSION AND CONCLUSIONS

Geniposide promoted diabetic wound healing by anti-inflammation and adjusting blood glucose. Further topical studies are required to evaluate effects on antibacterial activity and skin regeneration.