In this study, we introduce a novel graphene oxide/silver/arginine (GO/Ag/Arg) nanohybrid structure, which can act as an angiogenesis promoter and provide antibacterial nanostructure for improving the wound healing process. GO/Ag nanostructure has been optimized in terms of the GO/Ag mass ratio and pH values using central composite design and the response surface method to increase the Ag loading efficiency. Then, Arg was chemically introduced to the surface of GO/Ag nanostructure. Electrospun polycaprolactone (PCL)-GO/Ag/Arg nanocomposite was successfully fabricated and characterized. The synthesized nanocomposite demonstrated not only a great antibacterial effect on both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacterial species, but appropriate biocompatibility against L929 fibroblastic cell lines. The results demonstrated that the preparation of the PCL-GO/Ag/Arg nanocomposite at a concentration of 1.0 wt% GO/Ag/Arg possessed the best biological and mechanical features. In vivo experiments also revealed that the use of optimized PCL-GO/Ag/Arg nanocomposite, after 12 d of treatment, led to significant increase in the healing process and also regeneration of the wound via reconstruction of a thickened epidermis layer on the wound surface, which was confirmed by histological analysis. In conclusion, the proposed approach can introduce a novel notion for preparing antibacterial material that significantly promotes angiogenesis.

Background: Acetaminophen was falsely detected in the plasma of a severely jaundiced patient, and a methodologic interference from bilirubin was suspected. Methods: Acetaminophen was measured by an enzymatic method (GDS Diagnostics). The putative bilirubin interference was investigated in 12 hyperbilirubinemic specimens and in bilirubin linearity calibrators. The analytical method was modified to correct for background absorbance at a second wavelength. Hyperbilirubinemic specimens were fortified with acetaminophen to assess the effect of the interference on acetaminophen measurements. Results: Acetaminophen was detected in 12 specimens from hyperbilirubinemic patients without a history of recent acetaminophen exposure. Dilution of hyperbilirubinemic specimens produced a nonproportional decrease in apparent acetaminophen concentrations, and no acetaminophen was detected when bilirubin was <50 mg/L. Background correction at a second wavelength failed to compensate for the interference. Although erroneous acetaminophen concentrations were detected in all specimens with high bilirubin, acetaminophen measurements in fortified specimens were accurate. Conclusion: The data are consistent with bilirubin interference in the enzymatic and/or chromogenic reactions involved in the acetaminophen method.

Laser skin resurfacing has changed the approach of facial skin rejuvenation over the past decade. This article evaluates the laser effects on skin rejuvenation by the assessment of laser characteristics and histological and molecular changes, accompanied by the expression of proteins during and after laser-assisted rejuvenation of skin. It is important to note that different layers of skin with different cells are normally exposed to the sun’s UV radiation which is the most likely factor in aging and damaging healthy skin. To identify the expression of proteins, using validated databases and reviewing existing data could reveal altered proteins which could be analyzed and mapped to investigate their expression and their different effects on cell biological responses. In this regard, proteomics data can be used for better investigation of the changes in the proteomic profile of the treated skin. Different assessments have revealed the survival and activation of fibroblasts and new keratinocytes with an increase of collagen and elastin fibers in the dermis and the reduction of matrix metalloproteinases (MMPs) and heat shock proteins (HSPs) as a result of different lowpower laser therapies of skin. There are a wide range of biological effects associated with laser application in skin rejuvenation; therefore, more safety considerations should be regarded in the application of lasers in skin rejuvenation.

Repairing the lost or damaged mandible is very difficult and time-consuming, so there is a great hope for tissue engineering to accelerate it. At the present study, electrospinning was applied to fabricate polyvinylidene fluoride (PVDF) and PVDF-polyaniline (PANI) composite scaffolds. In addition, extremely low frequency pulsed electromagnetic field (PEMF) was applied for treating the stem cells derived from dental pulp (DPSCs) when cultured on the nanofibrous scaffolds. Osteoinductive property of the fabricated PVDF, PVDF-PANI scaffold at the presence and absence of the PEMF was investigated by evaluating the common osteogenic differentiation markers in seeded-DPSCs on the scaffold. Results demonstrated that cell attachment, protein adsorption and cells viability were increased when PEMF was applied. In addition, ALP activity, calcium content, osteogenic genes and protein evaluations confirmed that PEMF could significantly increase osteoinductivity of the PVDF while composite with PANI. According to the results, the use of polymers with piezoelectricity and conductivity features plus PEMF exposure has a promising potential to improve the current treatment methods in bone and mandibular defects.

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