Electrospinning-based wound dressings with multifunctional properties, including hemostasis-promoting, antibacterial, drug release, and therapeutic effects, are of great interest in military and civilian trauma healthcare. Herein, we designed lidocaine hydrochloride (LID) and mupirocin-loaded chitosan/polycaprolactone (CSLD-PCLM) scaffolds with multiple functions as wound dressings. Through the dual spinneret electrospinning technique, the scaffolds achieved a nanofiber structure, which enhanced the interfacial interaction between the scaffold and blood cells and showed excellent blood coagulation capacity. In particular, the scaffolds loaded with LID and mupirocin exhibited rapid release of LID and sustained release of mupirocin. The CSLD-PCLM scaffold containing mupirocin exhibited outstanding antibacterial activity. Moreover, the scaffold significantly enhanced the wound healing process with complete re-epithelialization as well as collagen deposition in a full-thickness skin defect model. Thus, CSLD-PCLM nanofibrous scaffolds may ideally meet the various requirements of the wound healing process and are promising candidates for wound dressings in future clinical applications.

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A novel series of biodegradable shape memory polyurethane ureas (SMPUUs) were designed and synthesized based on poly(D,L‐lactic acid) diol, hexamethylene diisocyanate and piperazine. Their structure, degree of crosslinking, thermal properties, shape memory behaviors and mechanical properties were characterized using Fourier transform infrared and 1H NMR spectroscopy, weight analysis, differential scanning calorimetry and tensile testing. The results reveal that successfully introducing the piperazine into the backbone of the SMPUUs gives them excellent shape memory behaviors and good mechanical properties. This, in combination with the ideal shape recovery temperature, which can be designed near human body temperature, could make these biodegradable polyurethanes of great interest as potential biomaterials for medical implantations. On increasing the percentage of hard content of the SMPUUs from 9.00 to 12.12 wt%, the shape fixation rate increases from 95.3 to 98.2%, but the shape recovery ratio decreases from 98.6 to 93.2%; also, both the tensile modulus and tensile strength increase, but elongation at break decreases. To profile the advantages of our SMPUUs, a polyurethane based on poly(D,L‐lactic acid) diol, hexamethylene diisocyanate and 1,4‐butanediamine was chosen as control. Copyright © 2011 Society of Chemical Industry

Cancer immunotherapy is a promising approach that has recently gained its importance in treating cancer. Despite various approaches of immunotherapies being used to target cancer cells, they are either not effective against all types of cancer or for all patients. Although efforts are being made to improve the cancer immunotherapy in all possible ways, one important hindrance that lowers the immune response to kill cancer cells is the infiltration of Regulatory T (Treg) cells into the tumor cells, favoring tumor progression, on one hand, and inhibiting the activation of T cells to respond to cancer cells, on the other hand. Therefore, new anti-cancer drugs and vaccines fail to show promising results against cancer. This is due to the infiltration of Treg cells into the tumor region and suppression of anti-cancer activity. Thus, regardless of various types of immunotherapies being practiced, understanding the mechanisms of how Treg cells favor tumor progression and inhibition of anti-cancer activity is worthwhile. Therefore, the review highlights the importance of Tregs cells and how depletion of Treg cells can pave the way to an effective immunotherapy by activating the immune responses against cancer.

A piperazine oligomer (PE) has been successfully synthesized via green and facile conditions. To obtain equivalent or better antimicrobial activity and smaller cytotoxicity, a mechano-growth factor and its 24-amino acid peptide analog corresponding to the unique C-terminal E-domain (MGF-Ct24E) was introduced to the side chain of PE. Fourier transform infrared spectrometry (FTIR), elemental analysis, and amino acid analyzer (AAA) measurements showed that the MGF-Ct24E-modified piperazine polymer (PEM) was successfully prepared. The antibacterial activity and cytotoxicity of PEM were further investigated. Introduction of MGF-Ct24E resulted in equivalent or improved antibacterial properties and reduced cytotoxicity compared to PE. The resulting material may replenish the current arsenal of synthetic polymeric antibacterial systems reported.