Multifunctional Covalent Organic Framework-Based Microneedle Patch for Melanoma Treatment.

Melanoma is resistant to conventional chemotherapy and radiotherapy. Therefore, it is essential to develop a targeted, low-toxic, and minimally invasive treatment. Here, DTIC/ICG-Fe3O4@TpBD BSP/HA microneedles (MNs) were designed and fabricated, which can enhance targeting to melanoma and perform photothermal therapy (PTT) and chemotherapy simultaneously to synergistically exert anticancer effects. The system consisted of magnetic nanoparticles (DTIC/ICG-Fe3O4@TpBD), dissoluble matrix (Bletilla polysaccharide (BSP)/hyaluronic acid (HA)), and a polyvinyl alcohol backing layer. Due to the good magnetic responsiveness of Fe3O4@TpBD, dacarbazine (DTIC) and indocyanine green (ICG) can be better targeted to the tumor tissue and improve the therapeutic effect. BSP and HA have good biocompatibility and transdermal ability, so that the MNs can completely penetrate the tumor tissue, be dissolved by the interstitial fluid, and release DTIC and ICG. Under near-infrared (NIR) light irradiation, ICG converts light energy into thermal energy and induces ablation of B16-OVA melanoma cells. In vivo results showed that DTIC/ICG-Fe3O4@TpBD BSP/HA MNs combined with chemotherapy and PTT could effectively inhibit the growth of melanoma without tumor recurrence or significant weight loss in mice. Therefore, DTIC/ICG-Fe3O4@TpBD BSP/HA MNs are expected to provide new ideas and therapeutic approaches for the clinical treatment of melanoma.

Self-implanted tiny needles as alternative to traditional parenteral administrations for controlled transdermal drug delivery.

Controlled drug-delivery systems have potential as substitutes for traditional medication systems due to the advantages in safety, efficacy, and patient compliance that these long-acting dosage forms provide. In this context, the present study focus on the development of self-implanted hyaluronic acid (HA) tiny needles that encapsulate ivermectin (IVM)-poly (lactic-co-glycolic acid) (PLGA) microparticles for controlled transdermal IVM release to treat parasitic diseases. The fabricated tiny needles involved matching portable applicator have potentially able for self-administration by patients without intense pain or complexity of current controlled-release devices. The biodegradable IVM-loaded PLGA microparticles were prepared and encapsulated within the tip of dissolving HA tiny needles to achieve high delivery efficiency. The drug loading of tiny needles might be controlled by varying the repeat time of filling or pressing processes. In-vitro tests showed that the tiny needles have sufficient mechanical strength to be inserted into skin within seconds and, next rapidly dissolved to release the loaded drug carriers into subcutaneous tissues for intradermal sustained IVM release. With the in-vivo test in rats, the insertion site recovered barrier property within 3 h. In comparison to traditional hypodermic injection or implantation of controlled-release systems, the proposed polymer tiny needles can be considered as a promising device for controlled transdermal drug delivery.

In vitro and in vivo assessment of polymer microneedles for controlled transdermal drug delivery.

Microneedles (MNs) system for transdermal drug delivery has the potential to improve therapeutic efficacy, proving an approach that is more convenient and acceptable than traditional medication systems. This study systematically researched dissolving polymer MNs fabricated from various common FDA-approved biocompatible materials, including gelatine, chitosan, hyaluronic acid (HA) and polyvinyl alcohol (PVA). Upon application of MN patches to the porcine cadaver skin, the MNs effectively perforated the skin and delivered drugs to subcutaneous tissue on contact with the interstitial fluid. Both the in vitro and in vivo drug release tests showed the similar trends but different release rates among the prepared MNs. Interestingly, the drug-release kinetics of PVA MNs were able to be altered by changing the molecular weight. To evaluate the feasibility using the proposed MNs for treating diabetes, an in vivo insulin absorption study in diabetic mice was performed. The results showed different insulin release properties of MNs fabricated from various kinds of polymer, leading to different decrease in blood glucose levels. We made a systematic and comprehensive study of some drug-loaded polymer MNs, and anticipated that dissolving polymer MNs have potential to improve therapeutic efficacy through controlled drug release.