Comparison treatment of medium-sized volar fingertips defects with modified triangular neurovascular unilateral advancement flap versus digital artery dorsal perforator flap.

PURPOSE: The reconstruction of medium-sized soft tissue defects of the fingertip remains a challenge for hand surgeons. The aim of this study was to compare the outcomes of modified triangular neurovascular unilateral advancement flap and digital artery dorsal perforator flap in the treatment of this injury. METHODS: From May 2018 to May 2022, 70 patients with medium-sized volar soft tissue defects were enrolled. The patients were divided into two groups based on the flap type: modified triangular neurovascular unilateral advancement flap (Group A) and digital artery dorsal perforator flap (Group B). The debridement times, defect size, operation time, and flap survival rate were recorded. At follow-up, hand function, aesthetics, and complications were evaluated. Function was evaluated using the TAM score. The aesthetics of the reconstructed and donor sites were assessed using the vancouver scar scale (VSS). The static two-point discrimination of the finger pulp served as a measure of tactile agnosia. RESULTS: A total of 10 patients were lost to follow-up for various reasons, resulting in 30 cases remaining in each group. The general information of the two groups showed no significant differences in age, sex, injury side, cause of injury, time from injury to surgery, and operation time (P > 0.05). Additionally, the debridement times and size of the defect were similar between the groups (P > 0.05). However, the operation time was significantly shorter in Group A compared to Group B (P = 0.001). With regard to complications, there was no significant difference between them. At one-month follow-up, TAM scores indicated that Group B performed significantly better than Group A. However, at the final follow-up period, there was no significant difference in TAM scores between the two groups. When considering the VSS, significant differences were observed between the two groups in both the reconstructed site and donor site. CONCLUSION: Both flaps can effectively repair medium-sized fingertip defects. Furthermore, the modified triangular neurovascular unilateral advancement flap offers anatomical reconstruction possibilities, ensuring satisfactory sensation and cosmetic contour.

A biocompatible superparamagnetic chitosan-based nanoplatform enabling targeted SN-38 delivery for colorectal cancer therapy.

7-Ethyl-10-hydroxycamptothecin (SN-38) as a potent anti-tumor candidate, suffers the constraints from its poor water solubility, pH-dependent lactone ring stability and the lack of efficient delivery system without losing its activity. Herein, biocompatible superparamagnetic chitosan-based nanocomplexes complexing with water-soluble polymeric prodrug poly(L-glutamic acid)-SN-38 (PGA-SN-38) was engineered for efficient delivery of SN-38. The manufacturing process of colloidal complexes was green, expeditious and facile, with one-shot addition of PGA-SN-38 into chitosan solution without using any organic solvent or surfactant. Upon introducing ultra-small-size superparamagnetic nanoparticles (~10 nm), the developed magnetic nanocomplexes exhibited significantly boosted tumor-targeted accumulation and efficient cellular internalization under a local magnetic field. Notably, the magnetic nanocomplexes achieved distinctly superior targeting and anti-tumor efficacy in the established xenograft colorectal cancer model of mice, with high tumor suppression rate up to 81%. Therefore, this superparamagnetic chitosan-based nanocomplex system could provide a promising platform for the targeted delivery of SN-38 in colorectal cancer therapy.

Superparamagnetic chitosan nanocomplexes for colorectal tumor-targeted delivery of irinotecan.

Conventional chemotherapy is effective for metastatic tumors widely present in colorectal cancer patients; however, chemotherapy may cause severe systemic toxicity due to a lack of specificity towards cancer cells. Effective delivery systems that can enhance targeted drug delivery to the desired tumor site and simultaneously protect the activity of drugs are in high demand. To that end, this study developed chitosan-based polyelectrolyte complexes (PECs) with the orientation of superparamagnetic nanoparticles, which enables the targeting delivery of the first-line model drug irinotecan (IRT) to the tumor area under a magnetic field. Colloidal PECs were mildly and facilely fabricated with chitosan and poly(glutamic acid) (PGA) via an all-in-water process, excluding the use of any potentially toxic chemicals. Iso-dispersed superparamagnetic Fe3O4 nanoparticles with relatively small particle diameters (~10 nm) were embedded into the IRT-loaded nano-PECs. The optimized nano-PECs showed high drug encapsulation capacity and improved anti-colon cancer cell efficacy compared with the free drug. Furthermore, the magnetic nano-PECs exhibited effective internalization by colon tumor cells, and favorable tumor-targeting ability was demonstrated via in vivo biodistribution study. Therefore, this magnetic targeted drug delivery nano-PECs system provides a promising platform to overcome the side effects of conventional chemotherapy for colorectal cancer.

Chitosan-based Colloidal Polyelectrolyte Complexes for Drug Delivery: A Review.

Polyelectrolyte complexes (PECs) as safe drug delivery carriers, are spontaneously formed by mixing the oppositely charged polyelectrolyte solutions in water without using organic solvents nor chemical cross-linker or surfactant. Intensifying attentions on the PECs study are aroused in academia and industry since the fabrication process of PECs is mild and they are ideal vectors for the delivery of susceptible drugs and macromolecules. Chitosan as the unique natural cationic polysaccharide, is a good bioadhesive material. Besides, due to its excellent biocompatibility, biodegradability, abundant availability and hydrophilic nature, chitosan-based PECs have been extensively applied for drug delivery, particularly after administration through mucosal and parenteral routes. The purpose of this review is to compile the recent advances on the biomedical applications of chitosan-based PECs, with specific focuses on the mucosal delivery, cancer therapy, gene delivery and anti-HIV therapy. The challenges and the perspectives of the chitosan-based PECs are briefly commented as well.