A novel chitosan derivant, N-octyl-N-arginine chitosan (OACS) with a mimetic structure of cell-penetrating peptides was synthesized by introducing hydrophilic arginine groups and hydrophobic octyl groups to the amino-group on chitosan's side chain. Structure of the obtained polymer was characterized by FT-IR and 1H NMR. The substitution degree of octyl and arginine groups was calculated through element analysis and spectrophotometric method, separately. The critical micelle concentration of OACS was 0.12 - 0.27 mgmL(-1) tested by fluorescence spectrometry. The solubility test showed OACS could easily dissolve in pH 1 - 12 solutions and self-assemble to form a micelle solution with light blue opalescence. The OACS micelles have a mean size of 158.4 - 224.6 nm, polydisperse index of 0.038 - 0.309 and a zeta potential of +19.16 - +30.80 mV determined by malvern zetasizer. AFM images confirmed free OACS micelle has a regular sphere form with a uniform particle size. MTT test confirmed that OACS was safe in 50 - 1 000 micromol-L(-1). The result of HepG2 cell experiment showed that the cell internalization of OACS micelles enhanced with increased substitution degree of arginine by 40 folds compared to chitosan. Thus, OACS micelles were a promising nano vehicle with permeation enhancement and drug carrier capability.

Objective To evaluate the safety and efficacy of transplantation of purified CD34 + cells (PCCs) in treatment of critical limb ischemia (CLI) caused by thromboangiitis obliterans (TAO).Methods From May 2009 to June 2015,34 TAO-induced-CLI cases underwent PCCs transplantation.None of these patients were eligible for surgical or endovascular revascularization.G-CSF was subcutaneously injected for 5 days before peripheral CD34 + cells were isolated,purified and intramuscularly injected in the limbs.Patients were regularly follow-up.Results Technical success was achieved in all cases.The mean number of transplanted cells was (7.5 ± 2.4) × 105/kg.The follow-up was accomplished in 32 cases,ranging from 6 to 79 months (mean 45 ±24 months),and two patients were lost.Wong-Baker FACES pain rating scale score significantly decreased from 8.0 ±2.0(4-10)to 2.2 ±3.1 (P ＜0.05) at 1 month.The Peak pain-free walking time improved from (4.0 ± 2.0) min to (13.5 ± 5.3) min (P ＜ 0.05) at 3 months and (19.0 ± 3.1) min (P ＜ 0.05) at 6 months.The ankle-brachial index increased from 0.42 ± 0.20 to 0.50 ± 0.10 (P ＜ 0.05) at 3 months and 0.52 ± 0.11 (P ＜ 0.05) at 6 months,respectively.Transcutaneous partial oxygen pressure rose from (25 ± 11) mmHg to (48 ± 11) mmHg(P ＜ 0.05) at 3 months and (58 ± 10) mmHg (P ＜ 0.001) at 6 months,respectively.Ulcers healed in 21 out of 22 patients at (5 ± 4) months.The overall amputation-free survival rate was 94.1％ at 6 months and 91.2％ at 48 months.No major adverse events were observed perioperatively or postoperatively.Conclusions Transplantation of PCCs could yield safe,satisfactory and durable treatment outcomes in patients with TAO-induced-CLI.