DSC Study of Collagen in Disc Disease

Differential scanning calorimetry (DSC) has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers

The influence of Polyquaternium-7 on the hair properties

The influence of UV-light with the wavelength 254 nm on the hair properties was detected. Hair was also treated by the Polyquaternium-7 which is commonly used in cosmetic preparations as conditioning agent. Mechanical properties were measured and the surface of hair was examined by  atomic force microscope

Effects of solar radiation on collagen-based biomaterials

The effect of solar radiation on collagen and collagen/synthetic polymer blends in the form of thin films and solutions has been studied by UV-VIS and FTIR spectroscopies. Films and solutions of collagen blended with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) were irradiated by solar light. It was found that UV-VIS spectra, which characterize collagen, collagen/PVA, and collagen/PVP blended films, were significantly altered by solar radiation. FTIR spectra of collagen, collagen/PVA, and collagen/PVP films showed that after solar irradiation, the positions of Amide A bands were shifted to lower wavenumbers. There was not any significant alteration in the position of Amide I and Amide II bands of collagen and its blends after solar radiation. The effect of solar UV radiation in comparison with artificial UV radiation has been discussed

Study on the thermal properties of poly(vinyl alcohol) in the presence of collagen

Crystallization of poly(vinyl alkohol) (PVA) in the presence of 1%, 3% and 5% of collagen has been studied by Differential Scanning Calorimetry (DSC). PVA samples containing 1%, 3% and 5% of collagen after melting were crystallized with different cooling rate. The melting temperature of poly(vinyl alcohol) PVA in the presence of 1%, 3% and 5% of collagen is little big bigger than that for pure PVA. Small amount of collagen in PVA increases melting temperature probably due to hydrogen bonding between PVA and collagen. Collagen contains several side groups capable to form hydrogen bonds with OH group of PVA. The amount of crystallinity in PVA containing 1%, 3% and 5% of collagen is little big smaller than for pure PVA. Small amount of collagen in PVA causes disorder between polymer chains of polymer and leads to decrease of crystallinity. Crystallization process occurs slower in PVA containing small amount of collagen than for pure melt PVA

Biomaterials with potential use in bone tissue regeneration-collagen/chitosan/silk fibroin scaffolds cross-linked by EDC/NHS

Blending of different biopolymers, e.g., collagen, chitosan, silk fibroin and cross-linking modifications of these mixtures can lead to new materials with improved physico-chemical properties, compared to single-component scaffolds. Three-dimensional scaffolds based on threecomponent mixtures of silk fibroin, collagen and chitosan, chemically cross-linked, were prepared and their physico-chemical and biological properties were evaluated. A mixture of EDC (N-(3- dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride) and NHS (N-hydroxysuccinimide) was used as a cross-linking agent. FTIR was used to observe the position of the peaks characteristic for collagen, chitosan and silk fibroin. The following properties depending on the scaffold structure were studied: swelling behavior, liquid uptake, moisture content, porosity, density, and mechanical parameters. Scanning Electron Microscopy imaging was performed. Additionally, the biological properties of these materials were assessed, by metabolic activity assay. The results showed that the three-component mixtures, cross-linked by EDC/NHS and prepared by lyophilization method, presented porous structures. They were characterized by a high swelling degree. The composition of scaffolds has an influence on mechanical properties. All of the studied materials were cytocompatible with MG-63 osteoblast-like cells.This research was founded by National Science Centre, grant 2018/31/N/ST8/01391 and by Polish National Agency for Academic Exchange, Iwanowska project PPN/IWA/2018/1/00064/U/00001

Wolne rodniki w chemii, biologii i medycynie

Wykład dotyczy różnorodnych aspektów związanych z powstawaniem, właściwościami i identyfikacją wolnych rodników. Szczegółowo przedstawione będzie działanie wolnych rodników na materię. Omówione zostaną różne metody generowania i wykorzystanie rodników w praktyce oraz procesy rodnikowe zachodzące samorzutnie w przyrodzie. Szczególna uwaga będzie poświęcona problemom związanym z wpływem wolnych rodników na organizmy żywe, ich działaniu patogennemu oraz sposobom zapobiegania tym negatywnym skutkom

The influence of KrF excimer laser irradiation on the surface of collagen and collagen/PVP films

The surface properties of collagen and collagen/poly(vinyl pyrrolidone) (PVP) films after KrF excimer laser irradiation (λ=248nm) were investigated by means of the technique of scanning electron microscopy (SEM) and optical microscopy (OM). The laser irradiation of the used specimens caused an expansion of materials above their surface with pronounced sings of its melting. The height of the ablated volume in a case of collagen film at a fluence of 1.1J/cm2 was approximately 5μm. A white damage appears on the treated surfaces at a threshold of 0.5J/cm2 with a single pulse and becomes more visible for a higher fluence. It is also noteworthy that along with increasing fluences (beginning from the fluence of 1.7J/cm2), the characteristic filaments at the spot edges are observed. The local heat and pressure generated by the laser radiation were able to induce bubble formation on the surface. Further bubble colliding and bursting produce a three-dimensional polymer “microfoam” structure with interconnected pores. These results can be of interest for some new applications