Regenerative medicine is becoming a rapidly evolving technique in today’s biomedical progress scenario. Scientists around the world suggest the use of naturally synthesized biomaterials to repair and heal damaged cells. Hydroxyapatite (HAp) has the potential to replace drugs in biomedical engineering and regenerative drugs. HAp is easily biodegradable, biocompatible, and correlated with macromolecules, which facilitates their incorporation into inorganic materials. This review article provides extensive knowledge on HAp and collagen-containing compositions modified with drugs, bioactive components, metals, and selected nanoparticles. Such compositions consisting of HAp and collagen modified with various additives are used in a variety of biomedical applications such as bone tissue engineering, vascular transplantation, cartilage, and other implantable biomedical devices.

This study involves the synthesis of hydroxyapatite and describes the preparation and characterization of polymer coatings based on poly(ethylene glycol) diacrylate and poly(ethylene glycol) and modified with bovine serum albumin and hydroxyapatite. Hydroxyapatite was obtained by wet chemical synthesis and characterized by X-ray diffraction and FTIR spectroscopy, and its Ca/P molar ratio was determined (1.69 ± 0.08). The ceramic and bovine serum albumin were used in the preparation of composite materials with the polymeric matrix. The chemical composition of coatings was characterized with FTIR spectroscopy, and their morphology was recorded with SEM imaging. Moreover, the measurements of surface roughness parameters and stereometric research were performed. The prepared coatings were subjected to in vitro studies in simulated body fluid and artificial saliva. Changes in chemical composition and morphology after immersion were examined with FTIR spectroscopy and SEM imaging. Based on the conducted research, it can be stated that applied modifiers promote the biomineralization process. The roughness analysis confirmed prepared materials were characterized by the micrometer-scale topography. The materials morphology and roughness, and the morphology of the newly formed apatite deposit, were dependent on the type of the used modifier, and the artificial fluid used in in vitro studies.

In the present work, hydroxyapatite-polymer materials were developed. The preparation, as well as characterization of the ceramic-polymer composites based on polyvinylpyrrolidone, sodium alginate, and gelatin were described. The system was enriched with the addition of common sage extract (Salvia officinalis). The antioxidant potential of sage aqueous extract and total polyphenol content was determined. The antioxidant capacity and total phenolic content of extract were equal to 86.06 ± 0.49% and 16.21 ± 0.58 mg gallic acid equivalents per gram of dry weight, respectively. Incubation studies in selected biological liquids were carried out to determine the biomineralization capacity on the surface of the composites and to examine the kinetics of release of the active substances from within the material. As a result of the incubation, a gradual release of the extract over time from the polymer matrix was observed; moreover, the appearance of new apatite layers on the composite surface was recorded as early as after 14 days, which was also confirmed by energy-dispersive X-ray spectroscopy (EDS) microanalysis. The composites were analyzed with Fourier transform infrared spectroscopy (FTIR) spectroscopy, and the morphology was recorded by scanning electron microscope (SEM) imaging. The in vitro biological studies allowed their cytotoxic effect on the reference L929 fibroblasts to be excluded. Further analysis of the biomaterials showed that enrichment with polyphenols does not support the adhesion of L929 cells to the surface of the material. However, the addition of these natural components stimulates human monocytes that constitute the first step of tissue regeneration.

The biomaterial coatings for bone tissue regeneration described in this study promote bioactivity. The ceramic-polymer composite coatings deposited on polylactide (PLA) plates contain polymers, namely polyvinylpyrrolidone (PVP)/polyethylene glycol (PEG), while the ceramic phase is hydroxyapatite (HA). Additionally, collagen (COL) and glutathione (GSH) are components of high biological value. Bone tissue materials requires additionally demanding tribological properties, which are thoroughly described in this research. These findings, presented herein for the first time, characterize this type of highly specific composite coating material and their indicate possible application in bone regeneration implants. Implementation of the collagen in the PVP/PEG/HA composite matrix can tailor demanding tribological performance, e.g., anti-wear and friction reduction. The addition of the ceramic phase in too high a content (15%) leads to the decreased swelling ability of materials and slower liquid medium absorption by composite coatings, as well as strong surface roughening and loosening tribological properties. In consequence, small particles of HA from the very rough composite crumble, having a strong abrasive effect on the sample surface. In conclusion, sample C composed of PVP/PEG/GSH/COL/HA (5%) exhibits high bioactivity, strong mechanical and tribological properties, the highest free surface energy, porosity, and accepted roughness to be implemented as a material for bone regeneration.

Bioactive calcium phosphate ceramics (CaPs) are one of the building components of the inorganic part of bones. Synthetic CaPs are frequently used as materials for filling bone defects in the form of pastes or composites; however, their porous structure allows modification with active substances and, thus, subsequent use as a drug carrier for the controlled release of active substances. In this study, four different ceramic powders were compared: commercial hydroxyapatite (HA), TCP, brushite, as well as HA obtained by wet precipitation methods. The ceramic powders were subjected to physicochemical analysis, including FTIR, XRD, and determination of Ca/P molar ratio or porosity. These techniques confirmed that the materials were phase-pure, and the molar ratios of calcium and phosphorus elements were in accordance with the literature. This confirmed the validity of the selected synthesis methods. CaPs were then modified with the antibiotic clindamycin. Drug release was determined on HPLC, and antimicrobial properties were tested against Staphylococcus aureus. The specific surface area of the ceramic has been demonstrated to be a factor in drug release efficiency.

This paper describes the plant-mediated preparation of silver nanoparticles with aqueous extract and infusion of Cistus incanus leaves. To evaluate aqueous extract and infusion antioxidant capacity and total phenolic content the DPPH and Folin–Ciocalteau methods were utilized. The antioxidant capacity and total phenolic content of extract and infusion were equal to 85.97 ± 6.54 mg gallic acid equivalents per gram of dry weight.; 10.76 ± 0.59 mg/mL and 12.65 ± 1.04 mg gallic acid equivalents per gram of dry weight.; 3.10 ± 0.14 mg/mL, respectively. The formed nanoparticles displayed the characteristic absorption band in the 380–450 nm wavelength range. The average size of particles was in the 68.8–71.2 nm range. Morphology and phase composition analysis revealed the formation of spherical nanoparticles with a face-centred cubic structure. Immune compatibility tests of nanoparticles and plant extracts showed no activation of the THP1-XBlue™ monocyte. Cytotoxicity tests performed with L929 mice fibroblasts showed that nanoparticles should be utilized at a concentration of 16 ppm. The minimum inhibitory concentrations determined with the microdilution method for nanoparticles prepared with plant infusion for S. aureus and S. epidermidis were 2 ppm and 16 ppm, respectively.