When Wounds Are Good for You: The Regenerative Capacity of Fractional Resurfacing and Potential Utility in Chronic Wound Prevention

Hydroxyapatite-Coated Small Intestinal Submucosa Membranes Enhanced Periodontal Tissue Regeneration through Immunomodulation and Osteogenesis via BMP-2/Smad Signaling Pathway

Periodontitis, a chronic infection causing periodontal tissue loss, may be effectively addressed with in situ tissue engineering. Small intestinal submucosa (SIS) offers exceptional biocompatibility and biodegradability but lacks sufficient osteoconductive and osteoinductive properties. This study develops and characterizes SIS coated with hydroxyapatite (SIS-HA) and gelatin methacrylate hydroxyapatite (SIS-Gel-HA) using biomineralization and chemical crosslinking. The impact on periodontal tissue regeneration is assessed by evaluating macrophage immune response and osteogenic differentiation potential of periodontal ligament stem cells (PDLSCs) in vitro and rat periodontal defects in vivo. The jejunum segment, with the highest collagen type I content, is optimal for SIS preparation. SIS retains collagen fiber structure and bioactive factors. Calcium content is 2.21% in SIS-HA and 2.45% in SIS-Gel-HA, with no significant differences in hydrophilicity, physicochemical properties, protein composition, or biocompatibility among SIS, SIS-HA, SIS-Gel, and SIS-Gel-HA. SIS is found to upregulate M2 marker expression, both SIS-HA and SIS-Gel-HA enhance the osteogenic differentiation of PDLSCs through the BMP-2/Smad signaling pathway, and SIS-HA demonstrates superior in vitro osteogenic activity. In vivo, SIS-HA and SIS-Gel-HA yield denser, more mature bones with the highest BMP-2 and Smad expression. SIS-HA and SIS-Gel-HA demonstrate enhanced immunity-osteogenesis coupling, representing a promising periodontal tissue regeneration approach.

Chronic Wound Healing Models

In this paper, we review and analyze the commonly available wound healing models reported in the literature and discuss their advantages and issues, considering their relevance and translational potential to humans. Our analysis includes different in vitro and in silico as well as in vivo models and experimental techniques. We further explore the new technologies in the study of wound healing to provide an all encompassing review of the most efficient ways to proceed with wound healing experiments. We revealed that there is not one model of wound healing that is superior and can give translatable results to human research. Rather, there are many different models that have specific uses for studying certain processes or stages of wound healing. Our analysis suggests that when performing an experiment to assess stages of wound healing or different therapies to enhance healing, one must consider not only the species that will be used but also the type of model and how this can best replicate the physiology or pathophysiology in humans.

Transdermal Drug Delivery in the Pig Skin

Transdermal delivery can be accomplished through various mechanisms including formulation optimization, epidermal stratum corneum barrier disruption, or directly by removing the stratum corneum layer. Microneedling, electroporation, a combination of both and also the intradermal injection known as mesotherapy have proved efficacy in epidermal-barrier disruption. Here we analyzed the effects of these methods of epidermal-barrier disruption in the structure of the skin and the absorption of four compounds with different characteristics and properties (ketoprofen, biotin, caffein, and procaine). Swine skin (Pietrain x Durox) was used as a human analogue, both having similar structure and pharmacological release. They were biopsied at different intervals, up to 2 weeks after application. High-pressure liquid chromatography and brightfield microscopy were performed, conducting a biometric analysis and measuring histological structure and vascular status. The performed experiments led to different results in the function of the studied molecules: ketoprofen and biotin had the best concentrations with intradermal injections, while delivery methods for obtaining procaine and caffein maximum concentrations changed on the basis of the lapsed time. The studied techniques did not produce significant histological alterations after their application, except for an observed increase in Langerhans cells and melanocytes after applying electroporation, and an epidermal thinning after using microneedles, with variable results regarding dermal thickness. Although all the studied barrier disruptors can accomplish transdermal delivery, the best disruptor is dependent on the particular molecule.

Microneedle arrays for the treatment of chronic wounds

INTRODUCTION

Chronic wounds are seen frequently in diabetic and bedbound patients. Such skin injuries, which do not heal in a timely fashion, can lead to life-threatening conditions. In an effort to resolve the burdens of chronic wounds, numerous investigations have explored the efficacy of various therapeutics on wound healing. Therapeutics can be topically delivered to cutaneous wounds to reduce the complications associated with systemic drug delivery because the compromised skin barrier is not expected to negatively affect drug distribution. However, researchers have recently demonstrated that the complex environment of chronic wounds could lower the localized availability of the applied therapeutics. Microneedle arrays (MNAs) can be exploited to enhance delivery efficiency and consequently improved healing.

AREAS COVERED

In this review, we briefly describe the pathophysiology of chronic wounds and current treatment strategies. We further introduce methods and materials commonly used for the fabrication of MNAs. Subsequently, the studies demonstrating the benefits of MNAs in wound care are highlighted.

EXPERT OPINION

Microneedles have great potential to treat the complicated pathophysiology of chronic wounds. Challenges that will need to be addressed include development of a robust chronic wound model and MNAs that combine complex functionality with simplicity of use.