1 Effect of poly(ethylene glycol) on insulin stability and cutaneous cell 1 proliferation in vitro following cytoplasmic delivery of insulin-loaded 2 nanoparticulate carriers – a potential topical wound management approach 3 4 5 6 Dalia H. Abdelkader 1,2 , Mohamed A. Osman 2 , Sanaa A. El-Gizawy 2 , Suzan J. Hawthorne 1 , 7 Ahmed M. Faheem 3 and Paul A. McCarron 1 * 8 9 10 11 1 School of Pharmacy and Pharmaceutical Sciences, Saad Centre for Pharmacy and Diabetes, 12 Ulster University, Cromore Road, Coleraine, Co. Londonderry, BT52 1SA, UK. 13 2 Faculty of Pharmacy, Pharmaceutical Technology Department, Tanta University, Tanta, 31111, 14 Egypt. 15 3 Sunderland Pharmacy School, University of Sunderland, Sunderland, SR1 3SD, UK. 16 17 18 19 20 *Corresponding author 21 Prof. Paul A. McCarron 22 School of Pharmacy and Pharmaceutical Sciences, 23 University of Ulster, 24 Cromore Road, 25 Coleraine, 26 Co. Londonderry, 27 BT52 1SA, UK 28 Tel: +44 (0) 28 70123285 29 Fax: +44 (0) 28 70123518 30 Email: p.mccarron@ulster.ac.uk 31 32