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oai:figshare.com:article/32640255 2026-10-01T16:32:51Z portal_1172 item_type_8 month_year_10_2026

The development of a 3D printed PEG-Chitosan-PCL dressing loaded with peptide-microRNA nanoparticles for wound healing Ying Sun (23237) PUREID: 614861913 Wound healing miRNA peptide nanoparticles polymers 3D-printing hot-melt extrusion Wound healing is a fundamental and dynamic process in the human body. Without prompt and adequate wound healing, the health of the patient is affected, leading to life-threatening consequences. Herein, microRNAs (miRs) were chosen as the genetic therapy by regulating multiple genes and associated pathways to promote cell proliferation and migration. The cell-penetrating peptide RALA was used for encapsulating plasmid encoding miR-31 and miR-132 (pmiR-31 and pmiR-132) to form self-assembled nanoparticles (NPs) with an average size ~80 nm and positive zeta-potential ~20 mV facilitating cellular entry. The miR expression level was increased in NCTC-929 cells transfected with heated and fresh RALA/pmiR NPs, indicating high temperature (<100°C) has no degradation effect on miR upregulation. The heating process is conducted to mimic the conditions of hot melt extrusion (HME) for fabricating polymer-based filaments, followed by Arburg Plastic Freeforming (APF) three-Dimensional Printing (3DP) process to produce 3D porous patches. Moreover, heated NPs effectively regulated target gene expression via RT-PCR and ELISA. PCL/PEG/chitosan-based 3D printed wound patches were fabricated with ideal physiochemical properties for wound healing via HME and 3DP, optimised through a Design of Experiments approach. Lyophilised peptide-DNA nanoparticles were successfully loaded into optimal PCL/PEG/chitosan filaments and the nanoparticles remained intact. The delivery of RALA/pmiR NPs from biocompatible 3D-printed patches to NCTC-929 and HacaT cells significantly improved cell migration, resulting in 50% wound reduction without hindering cell attachment, potentially preventing secondary injury upon patch removal. In the C57BL/6N murine full-thickness wound-healing model, NP-loaded 3D printed patches outperformed a commercial dressing, showing accelerated wound closure rate (80%), increased epidermal thickness (~80 µm) and blood vessel count (~2 fold) after 7 days. Taken together, these results demonstrated that peptide-DNA can be loaded in PCL/PEG/chitosan-based 3D printed patches without compromising the integrity of the biological cargo to result in improved wound closure and tissue repair.<br><br><i>Thesis is embargoed until 31 December 2029.</i> 2026-10-01T16:32:51Z Text Thesis 10.17034/32640255.v1 https://figshare.com/articles/thesis/The_development_of_a_3D_printed_PEG-Chitosan-PCL_dressing_loaded_with_peptide-microRNA_nanoparticles_for_wound_healing/32640255 All Rights Reserved Open Access after 2029-12-31