Search results for "Biomaterials"

Fabrication of amorphous strontium polyphosphate microparticles that induce mineralization of bone cells in vitro and in vivo.

2017

Abstract Here we describe the fabrication process of amorphous strontium-polyphosphate microparticles (“Sr-a-polyP-MP”). The effects of these particles on growth and gene expression were investigated with SaOS-2 cells as well as with human mesenchymal stem cells (MSC) and compared with those particles prepared of amorphous calcium-polyphosphate (“Ca-a-polyP-MP”) and of strontium salt. The results revealed a markedly higher stimulation of growth of MSC by “Sr-a-polyP-MP” compared to “Ca-a-polyP-MP” and a significant increase in mineralization of SaOS-2 cells, as well as an enhanced upregulation of the expression of the genes encoding for alkaline phosphatase and the bone morphogenetic protei…

Collagen-inducing biologization of prosthetic material for hernia repair: Polypropylene meshes coated with polyP/collagen

2017

Prostethic mesh material such as nonabsorbable polypropylene used in open and laparoscopic hernia repair are characterized by controllable mechanical properties but may elicit undesirable physiological reactions due to the nonphysiological inert polymer material. We succeeded in developing a biocompatible coating for these meshes, based on a physiological inorganic polymer, polyphosphate (polyP) that is morphogenetically active and used as a metabolic energy source, and a collagen matrix. The polyP/collagen hydrogel material was prepared by a freeze-extraction method, with amorphous Ca-polyP microparticles. Electron microscopy (SEM and REM) studies revealed that the polyP/collagen coats are…

In vitro evaluation of a biomaterial-based anticancer drug delivery system as an alternative to conventional post-surgery bone cancer treatment

2018

Patients diagnosed with osteosarcoma are currently treated with intravenous injections of anticancer agents after tumor resection. However, due to remaining neoplastic cells at the site of tumor removal, cancer recurrence often occurs. Successful bone regeneration combined with the control of residual cancer cells presents a challenge for tissue engineering. Cyclodextrins loaded with chemotherapeutic drugs reversibly release the drugs over time. Hydroxyapatite bone biomaterials coated with doxorubicin-loaded cyclodextrin should release the drug with time after implantation directly at the original tumor site and may be a way to eliminate residual neoplastic cells. In the present study, we h…

Monocyte preseeding leads to an increased implant bed vascularization of biphasic calcium phosphate bone substitutes via vessel maturation

2016

The present study analyzes the influence of the addition of monocytes to a biphasic bone substitute with two granule sizes (400-700 μm and 500-1000 μm). The majority of the added monocytes was detectable as mononuclear cells, while also low amounts of (chimeric) multinucleated giant cells (MNGCs) were found. No increase in the total number of MNGCs was established, but a significantly increased percent vascularization. Altogether, the results show that the added monocytes become involved in the tissue response to a biomaterial without marked changes in the overall reaction. Monocyte addition enables an increased implant bed vascularization especially via induction of vessel maturation and, …

FRET-based method for evaluation of the efficiency of reversible and irreversible sonoporation.

2017

It is widely known that not all of the treated cells survive after introduction of exogenous molecules via any physical method. Therefore, it is important to develop methods that would allow simultaneous evaluation of both molecular delivery efficiency and cell viability. This study presents Forster resonance energy transfer (FRET)-based method that allows molecular transfer and cell viability evaluation in a single measurement by employing two common fluorescent dyes, namely, ethidium bromide and trypan blue. The method has been validated using cell sonoporation. The FRET-based method allows the efficiency evaluation of both reversible and irreversible sonoporation in a single experiment. …

Effect of Low-Intensity Pulsed Ultrasound on Osteogenic Human Mesenchymal Stem Cells Commitment in a New Bone Scaffold

2017

Purpose Bone tissue engineering is helpful in finding alternatives to overcome surgery limitations. Bone growth and repair are under the control of biochemical and mechanical signals; therefore, in recent years several approaches to improve bone regeneration have been evaluated. Osteo-inductive biomaterials, stem cells, specific growth factors and biophysical stimuli are among those. The aim of the present study was to evaluate if low-intensity pulsed ultrasound stimulation (LIPUS) treatment would improve the colonization of an MgHA/Coll hybrid composite scaffold by human mesenchymal stem cells (hMSCs) and their osteogenic differentiation. LIPUS stimulation was applied to hMSCs cultured on …

Silver nanoparticle based coatings enhance adipogenesis compared to osteogenesis in human mesenchymal stem cells through oxidative stress.

2020

Silver nanoparticle (AgNP) based antibacterial surfaces were fabricated using plasma polymerization technology and their effects on differentiation of human bone-marrow derived mesenchymal stem cells (hMSCs) were investigated in this study. The results showed that AgNP coated surfaces do not affect the initial adhesion, spreading and proliferation of hMSCs. Furthermore, the silver coated surface promoted adipogenic differentiation of hMSCs as demonstrated by more accumulation of lipid droplets and upregulation of adipogenesis-related genes such as peroxisome proliferator activated receptor gamma (PPAR gamma), adipocyte determination and differentiation factor (ADD1) and CCAAT/enhancer bindi…

Single nanogranules preserve intracrystalline amorphicity in biominerals.

2015

We revisit the ultrastructural features of different calcareous biominerals and identify remarkable similarities: taxonomically very distant species show a common nanogranular structure, even if different extracellular secretion patterns are employed or calcium carbonate polymorphs formed. By these analyses, we elucidate the locus of the small fraction of intracrystalline organic matrix revealing its intergranular character and localize the intracrystalline amorphous calcium carbonate moiety commonly found in mesocrystalline biominerals and provide a first explanation for the pathway by which it is preserved.

Phototherapy: Ruthenium-Containing Block Copolymer Assemblies: Red-Light-Responsive Metallopolymers with Tunable Nanostructures for Enhanced Cellular…

2016

The effects of pressure on the energy landscape of proteins

2018

AbstractProtein dynamics is characterized by fluctuations among different conformational substates, i.e. the different minima of their energy landscape. At temperatures above ~200 K, these fluctuations lead to a steep increase in the thermal dependence of all dynamical properties, phenomenon known as Protein Dynamical Transition. In spite of the intense studies, little is known about the effects of pressure on these processes, investigated mostly near room temperature. We studied by neutron scattering the dynamics of myoglobin in a wide temperature and pressure range. Our results show that high pressure reduces protein motions, but does not affect the onset temperature for the Protein Dynam…