Multifunctional ZIF-91-Based GelMA Hydrogel Microneedles Patch with Antibacterial and Anti-Inflammatory Effects for Diabetic Wound Healing

Diabetic wound healing is a global biomedical challenge.
Bacterial
infection and microenvironmental modulation are major factors in the
refractory healing of diabetic wounds. Conventional therapeutic approaches
are often hindered by limitations, such as inadequate drug penetration,
the rise of antimicrobial resistance, and restricted depth of drug
delivery. Nanomedicine is emerging as a prospective drug delivery
and anti-infective therapeutic approach in the field of wound management.
Herein, all-trans retinoic acid (ATRA) was loaded into a zeolite imidazolate
framework-91 salt+ (ZIF-91 salt+). A gelatin
methacryloyl (GelMA) hydrogel microneedles (MNs) patch based on this
multifunctional ZIFs (denoted as GelMA-ZIF-91 salt+@ATRA
MNs patch) was developed, which makes transdermal drug delivery and
combinatory treatment for diabetic wound healing feasible. Significantly,
ATRA-containing ZIF-91 salt+ provides nanocomposites with
anti-inflammatory activity through their modulation of macrophage
polarization. Crucially, the prepared ZIF-91 salt+ showed
efficient antibacterial activity against Staphylococcus
aureus and Escherichia coli in vitro. Therapeutic effects of the GelMA-ZIF-91 salt+@ATRA MNs patch were verified in a diabetic mouse model with full-thickness
cutaneous wounds. A unique MNs patch with antimicrobial, angiogenesis-inducing,
and anti-inflammatory properties was designed in accordance with the
physiological characteristics of wounds. Collectively, the designed
MNs patch based on this multifunctional ZIF-91 salt+ provides
new insights into diabetic wound therapy.