Recurrent infection of chronic wounds remains a major clinical challenge. Recently, the hydrogel antibacterial materials have attracted extensive attention for preventing infection in wound healing. In this study, a hybrid hydrogel made of polyvinyl alcohol -iodine (PAI), sodium carboxymethyl cellulose (CMC), and carbamino quantum dot (CQDs) was prepared by the cross-linking of hydrogen bonds, named as polyvinyl alcohol-iodine/ sodium carboxymethyl cellulose/carbon quantum dots (PAI/CMC/CQDs). The composite hydrogels exhibited the outstanding photothermal conversion efficiency with near infrared (NIR) light irradiation, and the high anti-bacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Meanwhile, the elevated temperature of the composite hydrogels up to similar to 45 degrees C was able to stimulate the migration of epidermal cell to accelerate skin repair. Given that PAI and CQDs could respond to different pH values (5-8), the real-time would pH information was provided by the visible light and fluorescent light dual monitoring system by naked eye. Moreover, the visible-fluorescent images could be collected and transformed into RGB signals to quantify the would pH levels, avoiding secondary injuries caused by frequent dressing changes. PAI/CMC/CQDs was demonstrated the significant therapeutic effect on chronic wounds by eliminating bacterial infections and pro-moting skin repair under the smart RGB monitoring system.

Some reports have shown that CrmA could ameliorate the interleukin-1 beta induced osteoarthritis. In this study we investigated the effects of chitosan (CS)-CrmA nanoparticles (NPs) on metalloproteases expression (MMPs) in chondrocytes in vitro/in vivo and the underlying mechanism. CS-pDNA NPs were prepared by gel complex method and characterized. The expression of GFP and CrmA was detected by fluorescence microscope or western blot after the NPs were added into the culture medium of primary rabbit chondrocytes. Primary rabbit chondrocytes were treated with PBS, CS/pCDNA3.1 (+) or CS/pCDNA3.1 (+) CrmA NPs to analyze the changes of MMPs expression and apoptosis. Rabbit osteoarthritis (OA) models were established using anterior cruciate ligament transaction (ACLT) method. Nanoparticles including CS/pCrmA were injected into the rabbit joint once a week for one month after operation. All joint tissues were obtained to analyze the pathogenic changes, the expression levels of IL-1 beta, MMP-1, -3, -9, -13 by real-time RT-PCR, and cell apoptosis by TUNEL. The binding of CS and pDNA were verified by agarose gel electrophoresis. The in vitro release of pDNA in NPs at pH 2.0 and pH 7.0 presented a bi-phase kinetic release-curve. GFP and CrmA in CS/pDNA NPs were confirmed in rabbit primary chondrocytes. CS/pCrmA NPs can not only significantly inhibit apoptosis of the primary chondrocytes induced by IL-1 beta and the expression levels of MMP-1, -3, -9, and -13 compared with controls (P<0.05) but ameliorate the progression of osteoarthritis by inhibiting the primary chondrocytes apoptosis, which was further confirmed by histopathologic analysis. This study demonstrated that CS and CrmA in CS/pCrmA NPs synergistically inhibit the expression of MMPs, reduce chondrocyte apoptosis, and enhance the repair response of cartilage following cartilage insults. Altogether, CS/pCrmA NPs presented therapeutic potential for patients with osteoarthritis.

The activity of nano carbon fullerene lipidosome (NCFL) against influenza virus H1N1 in vitro was studied by observing the cytotoxicities and its activity rendered by different intensities of lighting with various periods of time. Rimantadine hydrochloride was used as the positive control drug. By using microcultural technique, the morphological changes of cells were observed and by using the gentian violet staining, antiviral activity of the NCFL against influenza virus was assayed. The results showed that: (1) The maximal concentration of the NCFL was 7 μg/mL and the 50% toxic concentration (TC50) was 13.54 μg/mL respectively; (2) NCFL had a significant activity of directly killing the influenza virus, while the activities in antiadsorption and antireplication were not obvious; (3) There was a dose-activity relationship between the dosages of NCFL and the direct killing effect against the influenza virus, and the periods of lighting-time could influence the activity partly. It was concluded that NCFL had a significant activity of directly killing the influenza virus.