Miniaturized Needle Array‐Mediated Drug Delivery Accelerates Wound Healing

Abstract

A major impediment preventing normal wound healing is insufficient vascularization, which causes hypoxia, poor metabolic support, and dysregulated physiological responses to injury. To combat this, the delivery of angiogenic factors, such as vascular endothelial growth factor (VEGF), has been shown to provide modest improvement in wound healing. Here, the importance of specialty delivery systems is explored in controlling wound bed drug distribution and consequently improving healing rate and quality. Two intradermal drug delivery systems, miniaturized needle arrays (MNAs) and liquid jet injectors (LJIs), are evaluated to compare effective VEGF delivery into the wound bed. The administered drug's penetration depth and distribution in tissue are significantly different between the two technologies. These systems' capability for efficient drug delivery is first confirmed in vitro and then assessed in vivo. While topical administration of VEGF shows limited effectiveness, intradermal delivery of VEGF in a diabetic murine model accelerates wound healing. To evaluate the translational feasibility of the strategy, the benefits of VEGF delivery using MNAs are assessed in a porcine model. The results demonstrate enhanced angiogenesis, reduced wound contraction, and increased regeneration. These findings show the importance of both therapeutics and delivery strategy in wound healing.

3D‐Printed Hydrogel‐Filled Microneedle Arrays

“…Animal work has also been done with needles of a similar length and shown success at improving wound healing. [ 38 ] In the case of a chronic wound application, the shorter needles would target the epidermis while longer needles could penetrate into the dermis and release their payload into these deeper layers. As an example, longer needles could be loaded with VEGF‐containing hydrogels to deliver these biochemical cues to the existing vasculature in the dermis.…”

Construction of multifunctional wound dressings with their application in chronic wound treatment

“…A recent report used hollow MNs to continuously deliver VEGF intradermally and showed the effect of promoting angiogenesis and wound healing in animal experiments. 65 However, due to their poor mechanical strength, hollow MNs have the risk of fracture during use. 66 Dissolvable MNs are usually made of water-soluble polymers such as HA.…”

3D-Printed Products for Topical Skin Applications: From Personalized Dressings to Drug Delivery

“…In vivo studies showed that VEGF delivery by miniaturized needles improved quality and healing rate, compared to the topically applied group. These effects were attributed to the distribution profile of VEGF through the miniaturized needles, affording a more uniform drug distribution through the wound area, and also a more accurate delivery to the target point, compared to the other methods [149].…”