NANOFIBERS FROM POLYVINYL ALCOHOL AND CAN ENLARGE THE SET OF TRAPPED ODOROLOGICAL TRACES

We tested collecting abilities of nanofibers made from polyvinyl alcohol and calcofluor (PVAC) for odorological trace collection. Our study revealed that spectrum of odorological traces trapped on nanofibrous PVAC absorbent is more stable and reproducible compared to commonly used ARATEXTM. In addition, both PVA and PVAC nanofibers can adhere a large number of traces undetectable by ARATEX.  Our results show that functionalization of commonly used absorbent ARATEXTM with PVA and PVAC nanofibers can vastly increase the accuracy of trace collection and, thus, significantly improve the forensic investigation

FUNCTIONALIZATION OF POLYMERIC NANOFIBERS USING PLATELETS FOR MELANOCYTE CULTURE

Tissue engineering is an interdisciplinary field that uses a combination of cells, suitable biomaterials and bioactive molecules to engineer the desired tissue and restore lost function. These principles have quickly begun to spread to the therapy of multiple diseases, including depigmentation disorders. The most common depigmentation disorder is vitiligo, a disease with deep psychosocial implications. Thanks to their unique properties, electrospun polymeric nanofibers represent a material suitable for tissue engineering applications. Furthermore, they may be functionalized with platelets, cells that contain a wide spectrum of growth factors and chemokines. The aim of this paper was to evaluate the functionalization of polymeric nanofibers with platelets and their effects in melanocyte culture. The scaffolds were visualized using scanning electron microscopy, the metabolic activity and proliferation of melanocytes was determined using MTS assay and dsDNA quantification, respectively. Furthermore, the melanocytes were stained and visualized using confocal microscopy. The acquired data showed that poly-ε-caprolactone functionalized with platelets promoted the viability and proliferation of melanocytes. According to the results, such a functionalized scaffold combining nanofibers and platelets may be suitable for melanocyte culture

Analysis and three-dimensional visualization of collagen in artificial scaffolds using nonlinear microscopy techniques

Extracellularly distributed collagen and chondro- cytes seeded in gelatine and poly-e-caprolactone scaffolds are visualized by two-photon excitation microscopy (TPEM) and second-harmonic generation (SHG) imaging in both for- ward and backward nondescanned modes. Joint application of TPEM and SHG imaging in combination with stereolog- ical measurements of collagen enables us not only to take high-resolution 3-D images, but also to quantitatively an- alyze the collagen volume and a spatial arrangement of cell-collagen-scaffold systems, which was previously im- possible. This novel approach represents a powerful tool for the analysis of collagen-containing scaffolds with applica- tions in cartilage tissue engineering. C 2010 Society of Photo-Optica

Allogeneic and autogenous transplantations of MSCs in treatment of the physeal bone bridge in rabbits

<p>Abstract</p> <p>Background</p> <p>The aim of this experimental study on New Zealand's white rabbits was to find differences in the results of treating the distal physeal femoral defect by the transplantation of autologous or allogeneic mesenchymal stem cells (MSCs). After the excision of a created bone bridge in the distal physis of the right femur, modified composite scaffold with MSCs was transplanted into the defect. In animal Group A (n = 11) autogenous MSCs were implanted; in animal Group B (n = 15) allogeneic MSCs were implanted. An iatrogenic physeal defect of the left femur of each animal not treated by MSCs transplantation served as control. The rabbits were euthanized four months after the transplantation. The treatment results were evaluated morphometrically (femoral length and valgus deformity measurement) and histologically (character and quality of the new cartilage).</p> <p>Results</p> <p>Four months after the transplantation, the right femurs of the animals in Group A were on average longer by 0.50 ± 0.04 cm (p = 0.018) than their left femurs, the right femurs of rabbits in Group B were on average longer by 0.43 ± 0.01 cm (p = 0.028) than their left femurs.</p> <p>4 months after the therapeutic transplantation of MSCs valgus deformity of the distal part of the right femur of animals in Group A was significantly lower (by 4.45 ± 1.86°) than that of their left femur (p = 0.028), in Group B as well (by 3.66 ± 0.95° than that of their left femur p = 0.001). However, no significant difference was found between rabbits with transplanted autogenous MSCs (Group A) and rabbits with transplanted allogeneic MSCs (Group B) either in the femur length (p = 0.495), or in its valgus deformity (p = 0.1597). After the MSCs transplantation the presence of a newly formed hyaline cartilage was demonstrated histologically in all the animals (both groups). The ability of transplanted MSCs to survive in the damaged physis was demonstrated in vivo by magnetic resonance, in vitro by Perls reaction and immunofluorescence.</p> <p>Conclusion</p> <p>The transplantation of both autogenous and allogeneic MSCs into a defect of the growth plate appears as an effective method of surgical treatment of physeal cartilage injury. However, the Findings point to the conclusion that there is no clear difference in the final effect of the transplantation procedure used.</p

Human DPSCs fabricate vascularized woven bone tissue : a new tool in bone tissue engineering

Human dental pulp stem cells (hDPSCs) are mesenchymal stem cells that have been successfully used in human bone tissue engineering. To establish whether these cells can lead to a bone tissue ready to be grafted, we checked DPSCs for their osteogenic and angiogenic differentiation capabilities with the specific aim of obtaining a new tool for bone transplantation. Therefore, hDPSCs were specifically selected from the stromal-vascular dental pulp fraction, using appropriate markers, and cultured. Growth curves, expression of bone-related markers, calcification and angiogenesis as well as an in vivo transplantation assay were performed. We found that hDPSCs proliferate, differentiate into osteoblasts and express high levels of angiogenic genes, such as vascular endothelial growth factor and platelet-derived growth factor A. Human DPSCs, after 40 days of culture, give rise to a 3D structure resembling a woven fibrous bone. These woven bone (WB) samples were analysed using classic histology and synchrotron-based, X-ray phase-contrast microtomography and holotomography. WB showed histological and attractive physical qualities of bone with few areas of mineralization and neovessels. Such WB, when transplanted into rats, was remodelled into vascularized bone tissue. Taken together, our data lead to the assumption that WB samples, fabricated by DPSCs, constitute a noteworthy tool and do not need the use of scaffolds, and therefore they are ready for customized regeneration

Polydatin Incorporated in Polycaprolactone Nanofibers Improves Osteogenic Differentiation

Polycaprolactone nanofibers are used as scaffolds in the field of tissue engineering for tissue regeneration or drug delivery. Polycaprolactone (PCL) is a biodegradable hydrophobic polyester used to obtain implantable nanostructures, which are clinically applicable due to their biological safety. Polydatin (PD), a glycosidic precursor of resveratrol, is known for its antioxidant, antitumor, antiosteoporotic, and bone regeneration activities. We aimed to use the osteogenic capacity of polydatin to create a biomimetic innovative and patented scaffold consisting of PCL-PD for bone tissue engineering. Both osteosarcoma cells (Saos-2) and mesenchymal stem cells (MSCs) were used to test the in vitro cytocompatibility of the PD-PCL scaffold. Reverse-phase (RP) HPLC was used to evaluate the timing release of PD from the PCL-PD nanofibers and the MTT assay, scanning electron microscopy, and alkaline phosphatase (ALP) activity were used to evaluate the proliferation, adhesion, and cellular differentiation in both osteosarcoma and human mesenchymal stem cells (MSCs) seeded on PD-PCL nanofibers. The proliferation of osteosarcoma cells (Saos-2) on the PD-PCL scaffold decreased when compared to cells grown on PLC nanofibers, whereas the proliferation of MSCs was comparable in both PCL and PD-PCL nanofibers. Noteworthy, after 14 days, the ALP activity was higher in both Saos-2 cells and MSCs cultivated on PD-PCL than on empty scaffolds. Moreover, the same cells showed a spindle-shaped morphology after 14 days when grown on PD-PCL as shown by SEM. In conclusion, we provide evidence that nanofibers appropriately coated with PD support the adhesion and promote the osteogenic differentiation of both human osteosarcoma cells and MSCs

Human DPSCs fabricate vascularized woven bone tissue: a new tool in bone tissue engineering

Human dental pulp stem cells (hDPSCs) are mesenchymal stem cells that have been successfully used in human bone tissue engineering. To establish whether these cells can lead to a bone tissue ready to be grafted, we checked DPSCs for their osteogenic and angiogenic differentiation capabilities with the specific aim of obtaining a new tool for bone transplantation. Therefore, hDPSCs were specifically selected from the stromal-vascular dental pulp fraction, using appropriate markers, and cultured. Growth curves, expression of bone-related markers, calcification and angiogenesis as well as an in vivo transplantation assay were performed. We found that hDPSCs proliferate, differentiate into osteoblasts and express high levels of angiogenic genes, such as vascular endothelial growth factor and platelet-derived growth factor A. Human DPSCs, after 40 days of culture, give rise to a 3D structure resembling a woven fibrous bone. These woven bone (WB) samples were analysed using classic histology and synchrotron-based, X-ray phase-contrast microtomography and holotomography. WB showed histological and attractive physical qualities of bone with few areas of mineralization and neovessels. Such WB, when transplanted into rats, was remodelled into vascularized bone tissue. Taken together, our data lead to the assumption that WB samples, fabricated by DPSCs, constitute a noteworthy tool and do not need the use of scaffolds, and therefore they are ready for customized regeneration

Myrtle-Functionalized Nanofibers Modulate Vaginal Cell Population Behavior While Counteracting Microbial Proliferation

Vaginal infections affect millions of women annually worldwide. Therapeutic options are limited, moreover drug-resistance increases the need to find novel antimicrobials for health promotion. Recently phytochemicals were re-discovered for medical treatment. Myrtle (Myrtus communis L.) plant extracts showed in vitro antioxidant, antiseptic and anti-inflammatory properties thanks to their bioactive compounds. The aim of the present study was to create novel nanodevices to deliver three natural extracts from leaves, seeds and fruit of myrtle, in vaginal milieu. We explored their effect on human cells (HeLa, Human Foreskin Fibroblast-1 line, and stem cells isolated from skin), resident microflora (Lactobacillus acidophilus) and on several vaginal pathogens (Trichomonas vaginalis, Escherichia coli, Staphylococcus aureus, Candida albicans, Candida kefyr, Candida glabrata, Candida parapsilosis, Candida krusei). Polycaprolactone-Gelatin nanofibers encapsulated with leaves extract and soaked with seed extracts exhibited a different capability in regard to counteracting microbial proliferation. Moreover, these nanodevices do not affect human cells and resident microflora viability. Results reveal that some of the tested nanofibers are interesting candidates for future vaginal infection treatments

Computer modelling reveals new conformers of the ATP binding loop of Na+/K+-ATPase involved in the transphosphorylation process of the sodium pump

Hydrolysis of ATP by Na+/K+-ATPase, a P-Type ATPase, catalyzing active Na+ and K+ transport through cellular membranes leads transiently to a phosphorylation of its catalytical α-subunit. Surprisingly, three-dimensional molecular structure analysis of P-type ATPases reveals that binding of ATP to the N-domain connected by a hinge to the P-domain is much too far away from the Asp369 to allow the transfer of ATP’s terminal phosphate to its aspartyl-phosphorylation site. In order to get information for how the transfer of the γ-phosphate group of ATP to the Asp369 is achieved, analogous molecular modeling of the M4–M5 loop of ATPase was performed using the crystal data of Na+/K+-ATPase of different species. Analogous molecular modeling of the cytoplasmic loop between Thr338 and Ile760 of the α2-subunit of Na+/K+-ATPase and the analysis of distances between the ATP binding site and phosphorylation site revealed the existence of two ATP binding sites in the open conformation; the first one close to Phe475 in the N-domain, the other one close to Asp369 in the P-domain. However, binding of Mg2+•ATP to any of these sites in the “open conformation” may not lead to phosphorylation of Asp369. Additional conformations of the cytoplasmic loop were found wobbling between “open conformation”  “semi-open conformation  “closed conformation” in the absence of 2Mg2+•ATP. The cytoplasmic loop’s conformational change to the “semi-open conformation”—characterized by a hydrogen bond between Arg543 and Asp611—triggers by binding of 2Mg2+•ATP to a single ATP site and conversion to the “closed conformation” the phosphorylation of Asp369 in the P-domain, and hence the start of Na+/K+-activated ATP hydrolysis