Amniotic Membrane Biopolymer for Regenerative Medicine.

Biopolymers based on the amniotic membrane compare favorably with synthetic materials in that, along with a specific 2D structure, they have biologically active properties. However, in recent years, there has been a tendency to perform decellularization of the biomaterial during the preparation of the scaffold. In this study, we studied the microstructure of 157 samples and identified individual biological components in the manufacture of a medical biopolymer from an amniotic membrane using various methods. Group 1 had 55 samples, and the amniotic membrane was impregnated with glycerol and dried over silica gel. Group 2 had 48 samples, and the decellularized amniotic membrane was impregnated with glycerol followed by lyophilization, Group 3 had 44 samples, and the decellularized amniotic membrane without pre-impregnation with glycerol was subjected to lyophilization. Decellularization was performed by treatment with a low-frequency ultrasound at a frequency of 24-40 kHz in an ultrasonic bath. A morphological study using a light microscope and a scanning electron microscope showed the preservation of the structure of the biomaterial and more complete decellularization in samples subjected to lyophilization without prior impregnation with glycerol. The study of the Raman spectroscopy lines of a biopolymer made from a lyophilized amniotic membrane without preliminary impregnation with glycerin showed significant differences in the intensity of the spectral lines of amides, glycogen, and proline. Additionally, in these samples, the spectral lines of Raman scattering the characteristic of glycerol were not visualized; therefore, only biological substances characteristic of the native amniotic membrane have been preserved.

Biopolymer Material from Human Spongiosa for Regenerative Medicine Application.

Natural biopolymers demonstrate significant bone and connective tissue-engineering application efficiency. However, the quality of the biopolymer directly depends on microstructure and biochemical properties. This study aims to investigate the biocompatibility and microstructural properties of demineralized human spongiosa Lyoplast® (Samara, Russian Federation). The graft's microstructural and biochemical properties were analyzed by scanning electron microscopy (SEM), micro-computed tomography, Raman spectroscopy, and proteomic analysis. Furthermore, the cell adhesion property of the graft was evaluated using cell cultures and fluorescence microscopy. Microstructural analysis revealed the hierarchical porous structure of the graft with complete removal of the cellular debris and bone marrow components. Moreover, the proteomic analysis confirmed the preservation of collagen and extracellular proteins, stimulating and inhibiting cell adhesion, proliferation, and differentiation. We revealed the adhesion of chondroblast cell cultures in vitro without any evidence of cytotoxicity. According to the study results, demineralized human spongiosa Lyoplast® can be effectively used as the bioactive scaffold for articular hyaline cartilage tissue engineering.

Raman Spectroscopy for Assessment of Hard Dental Tissues in Periodontitis Treatment.

The objective of this work was to use Raman spectroscopy to assess hard dental tissues after professional oral hygiene treatment and curettage. Spectral changes were identified, and the discriminant model of the specific changes of intensity of the Raman lines (i.e., of dentin, cementum, and enamel), before and after the dental procedures, was developed. This model showed that 6 weeks after the procedures, the hard dental tissues did not have differences and, thus, provided similar conditions for bio-film and dental plaque formation, tissue repair, and new attachment to the surface of the root.

Assessment of decellularization of heart bioimplants using a Raman spectroscopy method.

We report the results of experimental studies on cardiac implants using a Raman spectroscopy method (RS). Raman spectra characteristics of leaves and walls of cardiac implants were obtained; the implants were manufactured by protocols of detergent-enzymatic technique (DET) and biological, detergent-free (BIO) decellularization, using detergents (group DET) or a detergent-free, nonproteolytic, actin-disassembling regimen (BIO). There were input optical coefficients that allowed us to carry out evaluation of the protocols of DET and BIO decellularization on the basis of the concentrations of glycosaminoglycans, proteins, amides, and DNA. It was shown that during DET and BIO decellularization, composition aberrations of proteins and lipids do not occur and the integrity of the collagenous structures is preserved. It was found that during the DET decellularization, preservation of glycosaminoglycans is better than during BIO decellularization.

Improvement of the in vivo cellular repopulation of decellularized cardiovascular tissues by a detergent-free, non-proteolytic, actin-disassembling regimen.

Low immunogenicity and high repopulation capacity are crucial determinants for the functional and structural performance of acellular cardiovascular implants. The present study evaluates a detergent-free, non-proteolytic, actin-disassembling regimen (BIO) for decellularization of heart valve and vessel grafts, particularly focusing on their bio-functionality. Rat aortic conduits (rAoC; n = 89) and porcine aortic valve samples (n = 106) are decellularized using detergents (group DET) or the BIO regimen. BIO decellularization results in effective elimination of cellular proteins and significantly improves removal of DNA as compared with group DET, while the extracellular matrix (ECM) structure as well as mechanical properties are preserved. The architecture of rAoC in group BIO allows for improved bio-functionalization with fibronectin (FN) in a standardized rat implantation model: BIO treatment significantly increases speed and amount of autologous medial cellular repopulation in vivo (p < 0.001) and decreases the formation of hyperplastic intima (p < 0.001) as compared with FN-coated DET-decellularized grafts. Moreover, there are no signs of infiltration with inflammatory cells. The present biological, detergent-free, non-proteolytic regimen balances effective decellularization and ECM preservation in cardiovascular grafts, and provides optimized bio-functionality. Additionally, this study implies that the actin-disassembling regimen may be a promising approach for bioengineering of acellular scaffolds from other muscular tissues, as for example myocardium or intestine. Copyright © 2017 John Wiley & Sons, Ltd.