AgNPs-Modified Polylactic Acid Microneedles: Preparation and In Vivo/In Vitro Antimicrobial Studies

• Published in: Pharmaceutical research Vol. 41; no. 1; pp. 93 - 104
• Main Authors: Zhang, Wenqin, Cai, Xiaozhen, Zhang, Xinyi, Zou, Shiqi, Zhu, Danhong, Zhang, Qiulong, Chen, Jianmin
• Format: Journal Article
• Language: English
• Published: New York Springer US 2024; Springer; Springer Nature B.V
• Subjects: Antibacterial activity; Antibacterial agents; Biochemistry; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biopolymers; Biosensors; Detectors; Health aspects; Infection; Medical Law; Nanoparticles; Original Research Article; Pharmacology/Toxicology; Pharmacy; Physicochemical properties; Polylactic acid; Silver; Skin; Wound healing; antibacterial; polydopamine; silver nanoparticles; dopamine; polylactic acid microneedles
• ISSN: 0724-8741; 1573-904X
• DOI: 10.1007/s11095-023-03634-6

Objective To prepare polylactic acid microneedles (PLAMNs) with sustained antibacterial effect to avoid skin infection caused by traditional MNs-based biosensors. Methods Silver nanoparticles (AgNPs) were synthesized using an in-situ reduction process with polydopamine (PDA). PLAMNs were fabricated using the hot-melt method. A series of pressure tests and puncture experiments were conducted to confirm the physicochemical properties of PLAMNs. Then AgNPs were modified on the surface of PLAMNs through in-situ reduction of PDA, resulting in the formation of PLAMNs@PDA-AgNPs. The in vitro antibacterial efficacy of PLAMNs@PDA-AgNPs was evaluated using agar diffusion assays and bacterial liquid co-culture approach. Wound healing and simulated long-term application were performed to assess the in vivo antibacterial effectiveness of PLAMNs@PDA-AgNPs. Results The MNs array comprised 169 tiny needle tips in pyramidal rows. Strength and puncture tests confirmed a 100% puncture success rate for PLAMNs on isolated rat skin and tin foil. SEM analysis revealed the integrity of PLAMNs@PDA-AgNPs with the formation of new surface substances. EDS analysis indicated the presence of silver elements on the surface of PLAMNs@PDA-AgNPs, with a content of 14.44%. Transepidermal water loss (TEWL) testing demonstrated the rapid healing of micro-pores created by PLAMNs@PDA-AgNPs, indicating their safety. Both in vitro and in vivo tests confirmed antibacterial efficacy of PLAMNs@PDA-AgNPs. Conclusions In conclusion, the sustained antibacterial activity exhibited by PLAMNs@PDA-AgNPs offers a promising solution for addressing skin infections associated with MN applications, especially when compared to traditional MN-based biosensors. This advancement offers significant potential for the field of MN technology.