An in vitro assessment and comparative effectiveness of silanized-glutaraldehyde functionalized titanium surfaces with phosphatidylcholine and type I collagen grafts

Recent advances of physiochemical cues on surfaces for directing cell fates

Surface modification plays an essential role in dictating cell behavior and fate, as it creates a microenvironment that profoundly influences cell attachment, migration, proliferation, and differentiation. This review aims to the intricate interplay of culture surface properties, including topography, stiffness, charge, and chemical modifications, demonstrating their profound impact on cell destiny. We explore the nuanced responses of cells to varying surface topographies, from nano- to microscale features, elucidating the influence of geometric patterns and roughness. We also investigate the impact of substrate stiffness, highlighting the way cells perceive and respond to mechanical cues mimicking their native environments. The role of surface charge is examined, revealing how electrostatic interactions influence cell adhesion, signaling, and cell fate decisions. Finally, we delve into the diverse effects of chemical modifications, including the presentation of bioactive molecules, growth factors, and extracellular matrix (ECM) components, demonstrating their ability to guide cell behavior and stimulate specific cellular responses. This review offers comprehensive insights into the important role of surface properties in shaping cell fate, offering promising avenues for developing sophisticated cell culture platforms for applications in drug discovery, regenerative medicine, and fundamental research.

Attachment of Fibrinogen on Ion Beam Treated Polyurethane

Protein-stable coverage of the artificial implant is a key problem for biocompatibility. In the present study, a protein layer was attached covalently to a polyurethane surface treated by an ion beam. A plasma system consisting of a vacuum chamber (0.8 Pa pressure) with a high voltage electrode powered by a short pulse (20 μS pulse duration and 200 Hz pulse repetition) generator was designed. Polyurethane with a formulation certified as a material for medical implants was treated by nitrogen ions with an energy of 20 keV and 5 × 1014-1016 ions/cm2 fluence range. Wettability measurements, X-ray photoelectron, Raman, Fourier transform infrared attenuated total reflection, and ellipsometry spectra showed a significant change in the structure of the surface layer of the treated polyurethane. The surface of the treated polyurethane contained a carbonised layer containing condensed aromatic clusters with terminal free radicals. The surface energy of polyurethane surface increased from 33 to 65 mJ/m2. The treated polyurethane surface became capable of adsorbing and chemically binding protein (fibrinogen). The designed system for ion beam treatment can be used for surface activation of biomedical polymer devices, where a total protein coverage is required.

Cell Adhesion and Initial Bone Matrix Deposition on Titanium-Based Implants with Chitosan-Collagen Coatings: An In Vitro Study

In orthopedics, titanium (Ti)-alloy implants, are often considered as the first-choice candidates for bone tissue engineering. An appropriate implant coating enhances bone matrix ingrowth and biocompatibility, improving osseointegration. Collagen I (COLL) and chitosan (CS) are largely employed in several different medical applications, for their antibacterial and osteogenic properties. This is the first in vitro study that provides a preliminary comparison between two combinations of COLL/CS coverings for Ti-alloy implants, in terms of cell adhesion, viability, and bone matrix production for probable future use as a bone implant. Through an innovative spraying technique, COLL-CS-COLL and CS-COLL-CS coverings were applied over Ti-alloy (Ti-POR) cylinders. After cytotoxicity evaluations, human bone marrow mesenchymal stem cells (hBMSCs) were seeded onto specimens for 28 days. Cell viability, gene expression, histology, and scanning electron microscopy evaluations were performed. No cytotoxic effects were observed. All cylinders were biocompatible, thus permitting hBMSCs' proliferation. Furthermore, an initial bone matrix deposition was observed, especially in the presence of the two coatings. Neither of the coatings used interferes with the osteogenic differentiation process of hBMSCs, or with an initial deposition of new bone matrix. This study sets the stage for future, more complex, ex vivo or in vivo studies.

Surface configuration of microarc oxidized Ti with regionally loaded chitosan hydrogel containing ciprofloxacin for improving biological performance

The bacterial colonization and poor osseointegration of Ti implants significantly compromise their applications in load-bearing bone repair and replacement. To endorse the Ti with both excellent bioactivity and antibacterial ability, we developed a microarc oxidation coating that was modified uniformly by hydroxyapatite (HA) nanodots arrays and loaded regionally with chitosan hydrogel containing ciprofloxacin. The bonding between the HA nanodots covered coating and the chitosan hydrogel is further enhanced via silanization and chemical grafting of glutaraldehyde. Benefiting from the regionally loaded structure of the chitosan hydrogel, the chitosan hydrogel unloaded area can promote the cell adhesion and proliferation with excellent bioactivity, though relatively low OD value of cck8 has been observed at the beginning of the cell culturing. Whereas, the OD value of cck8 rises with the prolongation of the cell culturing time due to the degradation of the regionally loaded chitosan hydrogel. With the help of the laden ciprofloxacin in chitosan hydrogels, the sample effectively sterilizes the bacterial with a bacteriostatic ring. Therefore, regional loading of chitosan hydrogel containing ciprofloxacin on the modified microarc oxidation coating is a good approach to endorse Ti with both excellent bioactivity and antibacterial ability.

Combining Sandblasting, Alkaline Etching, and Collagen Immobilization to Promote Cell Growth on Biomedical Titanium Implants

Our objective in this study was to promote the growth of bone cells on biomedical titanium (Ti) implant surfaces via surface modification involving sandblasting, alkaline etching, and type I collagen immobilization using the natural cross-linker genipin. The resulting surface was characterized in terms topography, roughness, wettability, and functional groups, respectively using field emission scanning electron microscopy, 3D profilometry, and attenuated total reflection-Fourier transform infrared spectroscopy. We then evaluated the adhesion, proliferation, initial differentiation, and mineralization of human bone marrow mesenchymal stem cells (hMSCs). Results show that sandblasting treatment greatly enhanced surface roughness to promote cell adhesion and proliferation and that the immobilization of type I collagen using genipin enhanced initial cell differentiation as well as mineralization in the extracellular matrix of hMSCs. Interestingly, the nano/submicro-scale pore network and/or hydrophilic features on sandblasted rough Ti surfaces were insufficient to promote cell growth. However, the combination of all proposed surface treatments produced ideal surface characteristics suited to Ti implant applications.