Poly(lactic acid)-hyperbranched polyglycerol nanoparticles enhance bioadhesive treatment of esophageal disease and reduce systemic drug exposure

Novel approach for enhancing skin allograft survival by bioadhesive nanoparticles loaded with rapamycin

Skin graft rejection is a significant challenge in skin allografts for skin defects, particularly in extensive burn injury patients when autografts are insufficient. Enhancing the survival duration of allogeneic skin grafts can improve the success rate of subsequent autologous skin grafting, thereby promoting the therapeutic efficacy for wound healing. Rapamycin (Rapa), a potent immunosuppressant with favorable efficacy in organ transplantation, is limited by its systemic administration-associated toxicity and side effects. Therefore, addressing the short survival time of allogeneic skin grafts and minimizing the toxicity related to systemic application of immunosuppressive agents is an urgent requirement. Here, we present a topical formulation based on bioadhesive poly (lactic acid)-hyperbranched polyglycerol nanoparticles (BNPs) with surface-modified encapsulation of Rapamycin (Rapa/BNPs), applied for local immunosuppression in a murine model of allogeneic skin grafts. Our Rapa/BNPs significantly prolong nanoparticle retention, reduce infiltration of T lymphocytes and macrophages, decrease the level of pro-inflammatory cytokines and ultimately extend skin allograft survival with little systemic toxicity compared to free Rapa or Rapamycin-loaded non-bioadhesive nanoparticles (Rapa/NNPs) administration. In conclusion, Rapa/BNPs effectively deliver local immunosuppression and demonstrate potential for enhancing skin allograft survival while minimizing localized inflammation, thus potentially increasing patient survival rates for various types of skin defects.

PLA-HPG based coating enhanced anti-biofilm and wound healing of Shikonin in MRSA-infected burn wound

Burn wounds are susceptible to bacterial infections, including Methicillin-resistant Staphylococcus aureus (MRSA), which typically form biofilms and exhibit drug resistance. They also have specific feature of abundant exudate, necessitating frequent drug administration. Shikonin (SKN) has been reported to reverse MRSA drug resistance and possesses anti-biofilm and wound healing properties, however, it suffers from drawbacks of low solubility and instability. In this study, we developed PLA-HPG based bioadhesive nanoparticles SKN/BNP, which demonstrated a drug loading capacity of about 3.6%, and exhibited sustained-release behavior of SKN. The aldehyde groups present on the surface of BNP improved the local adhesion of SKN/BNP both in vitro and in vivo, thereby reducing the frequency of drug dosing in exudate-rich burn wounds. BNP alone enhanced proliferation and migration of the fibroblast, while SKN/BNP promoted fibroblast proliferation and migration as well as angiogenesis. Due to its bioadhesive property, BNP directly interacted with biofilm and enhanced the efficacy of SKN against MRSA biofilm in vitro. In a mouse model of MRSA-infected burn wounds, SKN/BNP demonstrated improved anti-biofilm and wound healing efficiency. Overall, our findings suggest that SKN/BNP holds great promise as a novel and effective treatment option for clinical applications in MRSA-infected burn wounds.

Nanoparticles as a Therapeutic Delivery System for Skin Cancer Prevention and Treatment

The use of nanoparticles (NPs) as a therapeutic delivery system has expanded markedly over the past decade, particularly regarding applications targeting the skin. The delivery of NP-based therapeutics to the skin requires special consideration owing to its role as both a physical and immunologic barrier, and specific technologies must not only take into consideration the target but also the pathway of delivery. The unique challenge this poses has been met with the development of a wide panel of NP-based technologies meant to precisely address these considerations. In this review article, we describe the application of NP-based technologies for drug delivery targeting the skin, summarize the types of NPs, and discuss the current landscape of NPs for skin cancer prevention and skin cancer treatment as well as future directions within these applications.

Microneedle-Assisted Topical Delivery of Idebenone-Loaded Bioadhesive Nanoparticles Protect against UV-Induced Skin Damage

Ultraviolet (UV) radiation can penetrate the basal layer of the skin and induce profound alterations in the underlying dermal tissues, including skin pigmentation, oxidative stress, photoaging, glycation, and skin cancer. Idebenone (IDB), an effective antioxidant that suppresses melanin biosynthesis and glycation, can protect the skin from UV-induced damage, accounting for its use in commercial anti-aging formulations. Ideally, IDB formulations should retain IDB inside the skin for a sufficient period, despite disturbances such as sweating or swimming. Herein, we present an IDB topical formulation based on Tris (tris(hydroxymethyl)-aminomethane)-modified bioadhesive nanoparticles (Tris-BNPs) and microneedle-assisted delivery. We found that Tris-BNPs loaded with IDB (IDB/Tris-BNPs) effectively reached the basal layer of the skin and were retained for at least 4 days with a slow and continuous drug release profile, unlike non-bioadhesive nanoparticles (NNPs) and bioadhesive nanoparticles (BNPs) of similar sizes (ranging from 120-142 nm) and zeta-potentials (above -20 mV), which experienced a significant reduction in concentration within 24 h. Notably, IDB/Tris-BNPs showed superior performance against UV-induced damage relative to IDB/NNPs and IDB/BNPs. This effect was demonstrated by lower levels of reactive oxygen species and advanced glycation end-products in skin tissues, as well as suppressed melanogenesis. Therefore, the proposed IDB delivery strategy provided long-term protective effects against UV-induced skin damage.