Detonation nanodiamonds biofunctionalization and immobilization to titanium alloy surfaces as first steps towards medical application

Low-temperature plasma induced phosphate groups onto coffee residue-derived porous carbon for efficient U(VI) extraction

For the continuous utilization of nuclear energy and efficient control of radioactive pollution, low-cost materials with high efficient U(VI) removal are of great importance. In this study, low temperature plasma method was applied for the successful modification of O-phosphorylethanolamine (O-PEA) on the porous carbon materials. The produced materials (Cafe/O-PEA) could adsorb U(VI) efficiently with the maximum sorption capacity of 648.54 mg/g at 1 hr, T=298 K, and pH=6.0, much higher than those of most carbon-based composites. U(VI) sorption was mainly controlled by strong surface complexation. From FTIR, SEM-EDS and XPS analyses, the sorption of U(VI) was related to the complexation with -NH₂, phosphate and -OH groups on Cafe/O-PEA. The low temperature plasma method was an efficient, environmentally friendly and low-cost method for surface modification of materials for the effective enrichment of U(VI) from aqueous solutions.

Customized Therapeutic Surface Coatings for Dental Implants

Dental implants are frequently used to support fixed or removable dental prostheses to replace missing teeth. The clinical success of titanium dental implants is owed to the exceptional biocompatibility and osseointegration with the bone. Therefore, the enhanced therapeutic effectiveness of dental implants had always been preferred. Several concepts for implant coating and local drug delivery had been developed during the last decades. A drug is generally released by diffusion-controlled, solvent-controlled, and chemical controlled methods. Although a range of surface modifications and coatings (antimicrobial, bioactive, therapeutic drugs) have been explored for dental implants, it is still a long way from designing sophisticated therapeutic implant surfaces to achieve the specific needs of dental patients. The present article reviews various interdisciplinary aspects of surface coatings on dental implants from the perspectives of biomaterials, coatings, drug release, and related therapeutic effects. Additionally, the various types of implant coatings, localized drug release from coatings, and how released agents influence the bone–implant surface interface characteristics are discussed. This paper also highlights several strategies for local drug delivery and their limitations in dental implant coatings as some of these concepts are yet to be applied in clinical settings due to the specific requirements of individual patients.

Modification of titanium implants using biofunctional nanodiamonds for enhanced antimicrobial properties

The present study describes a novel antimicrobial surface using anodic oxidation of titanium and biofunctional detonation nanodiamonds (ND). ND have been loaded with antibiotics (amoxicillin or ampicillin) using poly(diallyldimethylammonium chloride) (PDDA). Successful conjugation with PDDA was determined by dynamic light scattering, which showed increase in the hydrodynamic diameter of ND agglomerates and shift of zeta potential towards positive values. The surface loading of amoxicillin was determined using UV-vis spectroscopy and the maximum of 44% surface loading was obtained. Biofunctional ND were immobilized by anodic oxidation within a titanium oxide layer, which was confirmed by scanning electron microscopy. The in vitro antimicrobial properties of ND suspensions were examined using Kirby-Bauer test with E. coli. Modified titanium surfaces comprising biofunctional ND were evaluated with E. coli inoculum by live/dead assay staining. Both biofunctional ND suspensions and modified titanium surfaces presented inhibition of bacteria growth and increase in bacteria lethality.

Orthogonal Functionalization of Nanodiamond Particles after Laser Modification and Treatment with Aromatic Amine Derivatives

A laser system with a wavelength of 1064 nm was used to generate sp² carbon on the surfaces of nanodiamond particles (NDPs). The modified by microplasma NDPs were analysed using FT-IR and Raman spectroscopy. Raman spectra confirmed that graphitization had occurred on the surfaces of the NDPs. The extent of graphitization depended on the average power used in the laser treatment process. FT-IR analysis revealed that the presence of C=C bonds in all spectra of the laser-modified powder. The characteristic peaks for olefinic bonds were much more intense than in the case of untreated powder and grew in intensity as the average laser power increased. The olefinized nanodiamond powder was further functionalized using aromatic amines via in situ generated diazonium salts. It was also found that isokinetic mixtures of structurally diverse aromatic amines containing different functional groups (acid, amine) could be used to functionalize the surfaces of the laser-modified nanoparticles leading to an amphiphilic carbon nanomaterial. This enables one-step orthogonal functionalization and opens the possibility of selectively incorporating molecules with diverse biological activities on the surfaces of NDPs. Modified NDPs with amphiphilic properties resulting from the presence carboxyl and amine groups were used to incorporate simultaneously folic acid (FA-CONH-(CH₂)₅-COOH) and 5(6)-carboxyfluorescein (FL-CONH-(CH₂)₂-NH₂) derivatives on the surface of material under biocompatible procedures.

Utilizing DNA for functionalization of biomaterial surfaces

DNA sequences are widely used for gene transfer into cells including a number of substrate surface-based supporting systems, but due to its singular structure property profile, DNA also offers multiple options for noncanonical applications. The special case of using DNA and oligodeoxyribonucleotide (ODN) structures for surface functionalization of biomedical implants is summarized here with the major focus on (a) immobilization or anchoring of nucleic acid structures on substrate surfaces, (b) incorporation of biologically active molecules (BAM) into such systems, and (c) biological characteristics of the resulting surfaces in vitro and in vivo. Sterilizations issues, important for potential clinical applications, are also considered.

Graphene as an Enabling Strategy for Dental Implant and Tissue Regeneration

Graphene-based approaches have been influential in the design and manipulation of dental implants and tissue regeneration to overcome the problems associated with traditional titanium-based dental implants, such as their low biological affinity. Here, we describe the current progress of graphene-based platforms, which have contributed to major advances for improving cellular functions in in vitro and in vivo applications of dental implants. We also present opinions on the principal challenges and future prospects for new graphene-based platforms for the development of advanced graphene dental implants and tissue regeneration.