The unique capacity of mesenchymal stem cells (MSCs) to migrate to the sites of damage, following intravenous transplantation, along with their proliferation and differentiation abilities make them promising candidates for MSC-based gene therapy. This therapeutic approach requires high efficacy delivery of stable transgenes to ensure their adequate expression in MSCs. One of the methods to deliver transgenes is via the viral transduction of MSCs. However, due to low transduction efficiency of MSCs, various polications are used to promote the association of viral particles with membranes of target cells. Among these polications polybrene is the most widely used one. Unfortunately, viral infection in presence of polybrene was shown to negatively affect proliferation rate of stem cells. The molecular mechanism underlying this effect is not yet uncovered. Therefore, the present study aimed to elucidate the mechanism of this phenomenon as well as to develop an effective approach to overcome the negative impact of polybrene on the properties of human endometrium-derived mesenchymal stem cells (hMESCs) during lentiviral infection. We found that the negative effect on proliferation observed during the viral infection in presence of polybrene is mediated by the polycation itself. Furthermore, we revealed that the treatment with polybrene alone led to the p38 MAPK-dependent premature senescence of hMESCs. These findings allowed us to develop an effective strategy to attenuate the negative polybrene impact on the hMESCs properties during lentiviral infection by inhibiting the activity of p38 MAPK. Importantly, the proposed approach did not attenuate the transduction efficiency of hMESCs, yet prevented polybrene-induced senescence and thereby restored the proliferation of the infected cells. These results provide the plausible means to reduce side effects of polybrene during the viral infection of primary cells, particularly MSCs.

The main component of connective tissue and human organs — collagen protein is widely used in tissue engineering, regenerative medicine and cosmetology. The new methods search for assessing the structural and qualitative characteristics of collagen is currently an urgent area. This research is devoted to analyze by FTIR spectroscopy the various structural forms of collagen during the transition from molecular to fibrillar form and also collagen fibrils destruction. It was shown that during the formation of fibrils in the IR spectra, a peak arise with a wavenumber of 1083 cm−1. The magnitude of this peak can be used to judge the degree of fibrillation of molecular collagen in vitro. It was shown that the addition of a hydrogen peroxide solution with concentrations of 0.6, 1.5, and 3% in the initial solution with fibrillar collagen leads to the destruction of fibrils, which manifests itself in a noticeable fading of the peak with a wavenumber of 1083 cm−1.

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