Silk Fibroin/Poly(vinyl Alcohol) Microneedles as Carriers for the Delivery of Singlet Oxygen Photosensitizers

Abstract

Photodynamic therapy (PDT) is a medical treatment in which a combination of a photosensitizing drug and visible light produces highly cytotoxic reactive oxygen species (ROS) that leads to cell death. One of the main drawbacks of PDT for topical treatments is the limited skin penetration of some photosensitizers commonly used in this therapy. In this study, we propose the use of polymeric microneedles (MNs) prepared from silk fibroin and poly(vinyl alcohol) (PVA) to increase the penetration efficiency of porphyrin as possible applications in photodynamic therapy. The microneedle arrays were fabricated from mixtures in different proportions (1:0, 7:3, 1:1, 3:7, and 0:1) of silk fibroin and PVA solutions (7%); the polymer solutions were cast in polydimethylsiloxane (PDMS) molds and dried overnight. Patches containing grids of 10 × 10 microneedles with a square-based pyramidal shape were successfully produced through this approach. The polymer microneedle arrays showed good mechanical strength under compression force and sufficient insertion depth in both Parafilm M and excised porcine skin at different application forces (5, 20, 30, and 40 N) using a commercial applicator. We observe an increase in the cumulative permeation of 5-[4-(2-carboxyethanoyl) aminophenyl]-10,15,20-tris-(4-sulphonatophenyl) porphyrin trisodium through porcine skin treated with the polymer microneedles after 24 h. MNs may be a promising carrier for the transdermal delivery of photosensitizers for PDT, improving the permeation of photosensitizer molecules through the skin, thus improving the efficiency of this therapy for topical applications.

Silk Fibroin-Based Hydrogel Microneedles Deliver α-MSH to Promote Melanosome Delivery for Vitiligo Treatment

“…Through the quantitative statistics of cell viability, we found that SFMA did have a certain decrease effect on the viability of HaCaT, but there was no cytotoxicity (96% viability percentages). Ulloa Rojas et al proved that HaCaT cells cultured with SF/PVA microneedles presented above 75% viability percentages, which are potential low-toxic materials for biomedical use . In this research, we found that the modified SFMA/PVA hydrogel microneedles were non-cytotoxic to HaCaT cells, but the major problem of irritation and skin sensitization need to be examined in our future studies.…”

“…Ulloa Rojas et al proved that HaCaT cells cultured with SF/PVA microneedles presented above 75% viability percentages, which are potential low-toxic materials for biomedical use. 28 In this research, we found that the modified SFMA/PVA hydrogel microneedles were noncytotoxic to HaCaT cells, but the major problem of irritation and skin sensitization need to be examined in our future studies. The addition of α-MSH could promote the proliferation of HaCaT cells (Figure 4B).…”

Glucose-Responsive Silk Fibroin Microneedles for Transdermal Delivery of Insulin

“…Tuning the β-sheet range using methanol vapor annealing can aid in rapid and sustained drug release [ 28 , 31 , 32 ]. Rojas et al [ 33 ] blended PVA with SF to prepare polymer MNs, which can improve the transdermal delivery of porphyrins. Yin et al [ 34 ] developed an SF MNs drug delivery system with different small molecule reagents, with a tremendous transdermal drug release effect and little dissolution loss.…”

Insight into the structure and mechanical performance of high content lignin reinforced poly (vinyl alcohol) gel‐spun fibers via the regulation of esterified hydrophilic lignin composition for better sustainability

“…Several efforts have been made to enhance either the biodegradability or the physical properties of PVA matrix by the incorporation of bio‐based reinforcement materials (i.e., silk fibroin, 9 chitosan, 10 lignin, 11 and cellulose, 12 etc.). Among these bio‐based reinforcement materials, lignin is one of most abundant, cost‐effective, and biodegradable polymers on the earth.…”