Mariia Kumeda

The impact of ZnO, fullerene C ₆₀ and polyaniline (PANI) nanoparticles (NPs) on hybrid nerve conduits was studied to evaluate their role in peripheral nerve repair. Alginate–gelatin (Alg/Gel) conduits were synthesized via 5‐fold freeze‐thaw cycles under ultrasound and loaded with the NPs. Their effects on swelling, porosity, hydrophilicity, electrical conductivity, mechanical strength and vitamin B12 permeability were analysed. Composites with 0.15 mg/mL PANI showed increased conductivity: Alg/Gel/PANI (0.208 S/m), ZnO/Alg/Gel/PANI (0.744 S/m) and C ₆₀ /Alg/Gel/PANI (0.342 S/m), exceeding controls by 1.45–3.57 times. ZnO/Alg/Gel/PANI had the highest vitamin B12 permeability—55% over 7 days—due to its high porosity. Pure PANI showed low antioxidant activity (AOA, 17.6%), which rose to 46%–90% when combined with Alg and Gel. L929 cells remained viable in contact with all modified samples, indicating biocompatibility. Among the composites, C ₆₀ /Alg/Gel/PANI displayed superior mechanical stability and enhanced nerve regeneration potential, highlighting its promise for long‐term use in functional nerve repair. Highlights: Electrical conductivity increases up to 2 times in the presence of PANI, ZnO, fullerene C60 ZnO and C60 improve composites' mechanical stability and surface hydrophilicity The best permeability of vitamin B12 occurs through the ZnO/Alg/Gel/PANI wall In vivo in rat model study confirms the absence of toxicity and biocompatibility of composites

The healing of bone defects in the skull vault is a serious clinical problem. The aim of this study is to evaluate the effect of two osteoplastic materials on the healing of a cranial vault experimental defect by computed tomography. Two material systems are analyzed in detail: (i) a sodium alginate–based matrix modified with hydroxyapatite microparticles and zinc ions and (ii) a chitosan‐based matrix containing in situ–formed brushite nanoparticles; both sample types were loaded with cholecalciferol (VitD3). A total of 36 rats aged 6 months showed that the alginate‐based biomaterial promotes complete healing of the parietal bone defect after 200 days, whereas healing with the chitosan‐based biomaterials at that time was not complete. The second objective was to determine the kinetics of VitD3 release from experimental biocomposites using high‐performance liquid chromatography. The kinetics of VitD3 release depends on the material′s composition: The composite with chitosan prolongs the drug release to 48 h without the so‐called “burst release.” In the case of the alginate composite, a “burst release” of vitamin D3 is observed during the first 4 h. Both osteoplastic materials show the potential to optimize reparative osteogenesis in an experimental defect of the flat skull bone, although the regenerative potential of the alginate‐based biomaterial is higher.

Background: The problem of drug delivery to the tissue-damaged area of the human body remains relevant. Hydroxyapatite (HA), as one of the best known calcium phosphate (CaP) compounds, is used as an inorganic component of composite materials for drug loading. The organic components in composite materials are biopolymers such as alginate, agarose, chitosan (CS), collagen, and gelatin. Selected C60 nanoparticles are widely used as antibacterial agents and can strengthen the structure of composites. Microwave (MW) irradiation is an exposure method that shortens the synthesis time by significantly increasing the number of nucleation centers, which results the reducing the size of the crystallites formed, which affects the adsorption capacity of the product. Objectives: Most forms of drug delivery systems demonstrate rapid release of ceftriaxone (CFT) and anasthesin (ANA) within 2 days, characterized by a "burst release" that may cause overdose in the first hours of use. The aim of this work was to investigate and compare the drug release kinetics from convectionally and MW-synthesized CS matrices modified with HA, multiphasic CaP, and fullerene C60 nanoparticles for long-term bone tissue regeneration. Materials and methods: The study was performed by high-performance liquid chromatography (HPLC) using an Agilent 1200 device with a DAD detector (λ = 210–270 nm) and a C18 chromatographic column (Zorbax SB-C18 4.6×150 mm, 5 μm) at ambient temperature. Results: HA is a good adsorbent, but a poorly soluble substance, so the pharmacokinetics of ANA release was mainly determined by the degree of adsorption of the drug on the surface of the material and its diffusion potential. CS and C60 in the composition provide a prolonged release of ANA for up to 18 days. The release of CFT from CaP/CS matrices depends on the method of its introduction into the composite - during synthesis or saturation after synthesis. The saturation method is characterized by a fast release range of 24–48 hours, and adding during synthesis delays active release to 48–72 hours (start of degradation). The release index took values from n = 0.56 to n = 0.92, which corresponds to the release kinetics that does not follow Fick's law, and close to the first-order release kinetics model. Conclusions: Synthesized composites based on a CS matrix modified with nanostructured CaP particles and fullerene C60 are potential carriers of CFT and ANA with the function of their long-term release in areas of bone tissue injury.

Background. Innovative methods of regenerating damaged bone involve the use of new materials with incorporated biologically active molecules, stem cells, carbon and metal nanoparticles. Ceramics based on calcium orthophosphates are an alternative to native bone tissue, and their modification with nanoparticles (NPs) to improve the properties and functionality of composites is a new trend in the science of biomaterials. The known toxic effect of NPs on the human body by provoking oxidative stress through the formation of reactive oxygen species (ROS), an excessive amount of which causes DNA damage and death of surrounding cells requires the search for effective antioxidants for biomaterials. Materials and Methods. The study was conducted to review the literature on the use of biologically active compounds of plant origin, characterized by high antioxidant activity and osteoconductive properties, in biomedical engineering. Results. To accelerate implant osseointegration, it is important to protect bone cells from oxidative stress, which increases inflammation and can lead to implant rejection. The use of antioxidants, namely polyphenolic compounds, can improve the biocompatibility of biomaterials and increase their antioxidant properties. The review provides data on the use of such biologically active phytocompounds as extracts of medicinal plants (Fructus chebulae, Aloe vera, Camelia sinensis, Salvia officinalis), naringin, quercetin, kaempferol, resveratrol, catechins. By functionalizing biomaterials, the appropriate concentration of bioactive compounds in the implantation zone is maintained, and their release is controlled, which contributes to the neutralization of ROS, the proliferation and osteogenic differentiation of cells with osteogenic potential, the activity of osteoclasts is suppressed, and various signaling pathways are regulated. Conclusions. The analysis of literature sources has shown that polyphenolic compounds are promising phytocompounds used in the synthesis of innovative osteogenic biocomposite materials. The combination of polyphenols with various materials improves the biocompatibility, antioxidant properties, osteoconductivity and osteoinductivity of biomaterials. The ability of plant polyphenols to reduce inflammation and promote tissue regeneration, including bone, makes them promising compounds in biomolecular engineering.