HAP NPs Research Articles

Biomimetic In Vitro Model of Canine Periodontal Ligament.

Periodontal disease affects about 80% of dogs, highlighting the importance of addressing periodontitis in veterinary dental care. The periodontal ligament (PDL) is a key structure holding the potential to regenerate the entire periodontal complex. This work presents an in vitro model of canine PDL-derived cell cultures that mimic the PDL's regenerative capacity for both mineralised and soft tissues. Explant outgrowth-derived PDL cells were cultured under standard conditions in osteoinductive medium and with hydroxyapatite nanoparticles (Hap NPs). Cell behaviour was assessed for viability/proliferation, morphology, growth patterns, and the expression of osteogenic and periodontal markers. Osteogenic conditions, either achieved with osteoinducers or an osteoconductive biomaterial, strongly promoted PDL-derived cells' commitment towards the osteogenic phenotype and significantly increased the expression of periodontal markers. These findings suggest that cultured PDL cells replicate the biological function of the PDL, supporting the regeneration of both soft and hard periodontal tissues under normal and demanding healing conditions. This in vitro model will offer a platform for testing new regenerative treatments and materials, ultimately contributing to canine dental care and better outcomes.

Fabrication and characterization of PMMA denture base nanocomposite reinforced with hydroxyapatite and multi-walled carbon nanotubes

Polymethyl Methacrylate (PMMA) is still one of the most popular denture base materials in dentistry due to its superior mechanical properties. However, its long-term use can result in defects such as low flexural strength and brittleness, which can be addressed by strengthening its mechanical properties. In this study, the effect of adding non-modified and modified hydroxyapatite nanoparticles (HaP NPs) and multi-walled carbon nanotubes (MWCNTs) on the thermal and mechanical properties of PMMA denture base materials was investigated. First, the modified HaP (MHaP) NPs and modified MWCNTs (MMWCNTs) were prepared by a vinyltriethoxysilane (VTES) agent. Then, two-component PMMA-HaP/MHaP and PMMA-MWCNT/MMWCNT, and three-component PMMA-HaP/MHaP-MWCNT/MMWCNT composite samples were fabricated from commercial dental heat-curing acrylic resin (Acrosun) with different amounts of HaP/MHaP (3, 5, and 10 wt%) and MWCNT/MMWCNT (0.25, 0.5, and 1 wt%). The samples were investigated by Simultaneous Thermal Analysis (STA), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDS), Dynamic Mechanical Analysis (DMA), and Three-point flexural test. It was observed that surface modification of NPs improved the interaction of NPs and polymer chains in the matrix and resulted in better mechanical properties of nanocomposites. In the sample containing 3 wt% MHaP and 0.25 wt% MMWCNT, the flexural strength and flexural modulus were increased by 45 % and 42 % compared to the control sample, respectively, and the glass transition temperature (Tg) based on the DMA test was 152.7 °C, which was higher than in the other samples. The results of MTT assay studies indicated that adding MHaP and MMWCNT enhanced cell viability. In the PMMA- 3 wt% MHaP- 0.25 wt% MMWCNT composite, the cell viability was increased to 153.75 ± 9.7 % and confirmed its biocompatibility properties.

Thermosensitive injectable dual drug-loaded chitosan-based hybrid hydrogel for treatment of orthopedic implant infections

A myriad of therapeutic agents and drug delivery systems are available to the surgeons for treating orthopedic implant-associated infections (OIAI), but only very few have demonstrated their effectiveness in preventing bacteria colonization and biofilm formation due to challenges in the local and sustainable therapeutic release. To address this issue, in this work, a thermosensitive injectable hydrogel based on chitosan (CH)-integrated hydroxyapatite nanoparticles (HAP NPs) containing vancomycin (Van) and quercetin (QC)-loaded in F127 micelles (CH-HAP-FQ-Van hydrogel) was fabricated with potential application in the treatment of OIAI. This dual drug delivery system demonstrated a pH-sensitive drug release pattern. In addition, 100 % growth inhibition of Staphylococcus aureus for a duration of 14 days was observed. Apart from the strong antioxidant activities owing to the co-administration of QC even after 432 h, this composite hydrogel revealed 95.88 ± 2.8 % S. aureus biofilm eradication. By consideration of degradation stability (53.52 ± 4.24 %) during 60 days along with smart gelation within 10 min at 37 °C and easy injectability, CH-HAP-FQ-Van hydrogel could be used as a promising ideal local drug delivery system for implant-related infections.

Biofabrication and Characterization Using Egg Shell Nanoparticles and their Haemolytic Analysis: An in-vitro Study

Abstract: Aim/Background: Hydroxyapatite is a bioactive, biocompatible, and osteoconductive component having similar chemical characteristics to bone and tooth mineral components. Due to its porous structure and resistance to high temperatures, hydroxyapatite is commonly used as a catalyst and adsorbent. Eggshells are abundant in calcium carbonate, calcium phosphate, and other organic chemicals, making them excellent for CaO production. Materials and Methods: ES-Hap NPs from eggshell through an oil-bath-mediated precipitation technique. Egg shell nanoparticles were manufactured using chemical reagents like ammonia in a silicone oil bath. Preparation using a series of chemical reagents and characterization were done; functional groups were analysed using FTIR; and morphological analysis was analysed using FESEM. Hemolysis analysis was also done. Results: FTIR analysis showed functional PO4 groups, for the ES-Hap NPs at 1015 cm-1 and 563 cm-1, respectively. The XRD results based on crystallinity demonstrated Hap NPs of 20.86 nm. A FESEM investigation established the dimensions of NRs to be 78.15 nm and 221.62 nm, respectively. Crystallite size demonstrated that Hap NPs are comparable to normal human bone and may be employed as regenerative therapies. In addition, the hemolysis testing demonstrated superior blood compatibility compared to chemically manufactured, traditional Hap. Conclusion: These biogenic ES-Hap NPs can be further analysed for antimicrobial properties and in vivo studies, which could be highly beneficial for medical applications. Keywords: Egg shell, Nanoparticles, Hemolytic analysis, XRD, FTIR, FESEM.

Effect of Sintering Temperature on the Structural and Morphological Properties of Hydroxyapatite Prepared by Precipitation Method

Hydroxyapatite nanoparticles (HAp-NPs) were prepared using a precipitation route from an aqueous solution at a 1.66 Ca/P ion ratio and sintered at different temperatures. X-ray diffraction (XRD) was used to investigate the structural properties of the prepared films. Using a Field Emission Scanning Electron Microscope, the morphology of the surfaces was analyzed. Using Fourier Transform Infrared (FTIR) Spectroscopy, the surface's chemical composition and chemical bonding information were identified. The structural analysis shows that heating treatment reduced the broadening of diffraction peaks, enhancing the Hydroxyapatite phase crystallinity. No phase transition was observed as the sintering temperature increased, revealing the HAp phase's high stability. SEM micrograph images revealed a nanostructured foam-like structure that changed into a flake-shaped structure with diameters between 300 nm and 600 nm after heat treatment. FTIR spectroscopy results revealed that the heat treatment improved the crystallization of the developed HAp-NPs samples. Barrett-Joyner-Halenda (BJH) was used to determine the pore size of HAp NPs, whereas Brunauer-Emmett-Teller (BET) analysis was employed to characterize the surface area of the samples.

A Novel Hydroxyapatite/Vitamin B12 Nanoformula for Treatment of Bone Damage: Preparation, Characterization, and Anti-Arthritic, Anti-Inflammatory, and Antioxidant Activities in Chemically Induced Arthritic Rats.

The usage of nanomaterials for rheumatoid arthritis (RA) treatment can improve bioavailability and enable selective targeting. The current study prepares and evaluates the in vivo biological effects of a novel hydroxyapatite/vitamin B12 nanoformula in Complete Freund's adjuvant-induced arthritis in rats. The synthesized nanoformula was characterized using XRD, FTIR, BET analysis, HERTEM, SEM, particle size, and zeta potential. We synthesized pure HAP NPs with 71.01% loading weight percentages of Vit B12 and 49 mg/g loading capacity. Loading of vitamin B12 on hydroxyapatite was modeled by Monte Carlo simulation. Anti-arthritic, anti-inflammatory, and antioxidant effects of the prepared nanoformula were assessed. Treated arthritic rats showed lower levels of RF and CRP, IL-1β, TNF-α, IL-17, and ADAMTS-5, but higher IL-4 and TIMP-3 levels. In addition, the prepared nanoformula increased GSH content and GST antioxidant activity while decreasing LPO levels. Furthermore, it reduced the expression of TGF-β mRNA. Histopathological examinations revealed an improvement in joint injuries through the reduction of inflammatory cell infiltration, cartilage deterioration, and bone damage caused by Complete Freund's adjuvant. These findings indicate that the anti-arthritic, antioxidant, and anti-inflammatory properties of the prepared nanoformula could be useful for the development of new anti-arthritic treatments.

Hierarchical and urchin-like chitosan/hydroxyapatite microspheres as drug-laden cell carriers

Biopolymer/hydroxyapatite (HAp) composites are one type of the most promising materials for a variety of biomedical applications. In this study, hierarchical and urchin-like chitosan/HAp nanowire (HU-CS/HAp NW) microspheres were for the first time synthesized by in situ hydrothermal treatment of chitosan/HAp (CS/HAp) microspheres in the acetic acid solution. The results indicate that HU-CS/HAp NW microspheres were spherical in morphology with a diameter of 100–300 μm. Their surface was mainly constructed by numerous HAp NWs with the diameter of 80–120 nm and showed a hierarchical and urchin-like nanofibrous architecture. It was found that the acidic hydrothermal treatment caused an in situ conversion of HAp NPs to HAp NWs. In vitro biocompatible evaluation indicates that HU-CS/HAp NW microspheres showed an enhanced cell attachment and proliferation due to the presence of hierarchical and urchin-like architecture. Furthermore, HU-CS/HAp NW microspheres showed a good adsorption capacity for tetracycline hydrochloride (model drug, one of the most representative antibiotics) with a higher adsorption capacity than CS/HAp microspheres and well maintained their antibacterial efficacy to inhibit the growth of bacteria: Escherichia coli and Staphylococcus aureus. Thus, the present HU-CS/HAp NW microspheres would be applicable as novel drug-laden cell carriers.

The Application of Hydroxyapatite NPs for Adsorption Antibiotic from Aqueous Solutions: Kinetic, Thermodynamic, and Isotherm Studies

Antibiotic pollution has become a serious concern due to the extensive use of antibiotics, their resistance to removal, and their detrimental effects on aquatic habitats and humans. Hence, developing an efficient antibiotic removal process for aqueous solutions has become vital. Amoxicillin (Amox) is one of the antibiotics that has been efficiently removed from an aqueous solution using hydroxyapatite nanoparticles (HAP NPs). The current study synthesizes and utilizes hydroxyapatite nanoparticles as a cost-effective adsorbent. Adsorbent dose, pH solution, initial Amox concentration, equilibrium time, and temperature are among the factors that have an evident impact on Amox antibiotic adsorption. The (200) mg dose, pH (5), temperature (25) °C, and time (120) min are shown to be the best-optimized values. The nonlinear Langmuir’s isotherm and pseudo-second-order kinetic models with equilibrium capacities of 4.01 mg/g are highly compatible with the experimental adsorption data. The experimental parameters of the thermodynamic analysis show that the Amox antibiotic adsorption onto HAP NPs powder is spontaneous and exothermic.

Multifunctional Scaffolds Based on Emulsion and Coaxial Electrospinning Incorporation of Hydroxyapatite for Bone Tissue Regeneration

Tissue engineering is nowadays a powerful tool to restore damaged tissues and recover their normal functionality. Advantages over other current methods are well established, although a continuous evolution is still necessary to improve the final performance and the range of applications. Trends are nowadays focused on the development of multifunctional scaffolds with hierarchical structures and the capability to render a sustained delivery of bioactive molecules under an appropriate stimulus. Nanocomposites incorporating hydroxyapatite nanoparticles (HAp NPs) have a predominant role in bone tissue regeneration due to their high capacity to enhance osteoinduction, osteoconduction, and osteointegration, as well as their encapsulation efficiency and protection capability of bioactive agents. Selection of appropriated polymeric matrices is fundamental and consequently great efforts have been invested to increase the range of properties of available materials through copolymerization, blending, or combining structures constituted by different materials. Scaffolds can be obtained from different processes that differ in characteristics, such as texture or porosity. Probably, electrospinning has the greater relevance, since the obtained nanofiber membranes have a great similarity with the extracellular matrix and, in addition, they can easily incorporate functional and bioactive compounds. Coaxial and emulsion electrospinning processes appear ideal to generate complex systems able to incorporate highly different agents. The present review is mainly focused on the recent works performed with Hap-loaded scaffolds having at least one structural layer composed of core/shell nanofibers.

Bioinspiration synthesis of hydroxyapatite nanoparticles using eggshells as a calcium source: Evaluation of Congo red dye adsorption potential

Hydroxyapatite nanoparticles (HAp NPs) were synthesized with Muntingia calabura leaf extract as solvent and eggshell waste as a calcium source. The synthesized nanoparticles were irregular rod-like, as visualized by FESEM, while EDX and XPS studies confirmed the formation of hydroxyapatite. The synthesized HAp NPs were polycrystalline and highly thermostable as per XRD and TGA studies respectively. FTIR confirmed the stable coating of plant phytochemicals onto the HAp NPs. Congo red adsorption using HAp NPs nanoadsorbent was optimized by central composite design, wherein 89.96% of 33.18 mg/L dye was adsorbed in 137 min at 180 RPM. The adsorption process was in line with pseudo-second-order model and the Freundlich isotherm indicated chemical adsorption. The adsorption process was feasible, exothermic, and spontaneous as indicated by the thermodynamic studies. The adsorption capacity of HAp NPs stood at a maximum of 217 mg/g, indicating its superiority among other adsorbents reported earlier. It is evident from the convincing results that the HAp NPs synthesized in the present investigation may have a major role in developing novel adsorbents for dye removal out of wastewater streams.

Hydroxyapatite Biobased Materials for Treatment and Diagnosis of Cancer.

Great advances in cancer treatment have been undertaken in the last years as a consequence of the development of new antitumoral drugs able to target cancer cells with decreasing side effects and a better understanding of the behavior of neoplastic cells during invasion and metastasis. Specifically, drug delivery systems (DDS) based on the use of hydroxyapatite nanoparticles (HAp NPs) are gaining attention and merit a comprehensive review focused on their potential applications. These are derived from the intrinsic properties of HAp (e.g., biocompatibility and biodegradability), together with the easy functionalization and easy control of porosity, crystallinity and morphology of HAp NPs. The capacity to tailor the properties of DLS based on HAp NPs has well-recognized advantages for the control of both drug loading and release. Furthermore, the functionalization of NPs allows a targeted uptake in tumoral cells while their rapid elimination by the reticuloendothelial system (RES) can be avoided. Advances in HAp NPs involve not only their use as drug nanocarriers but also their employment as nanosystems for magnetic hyperthermia therapy, gene delivery systems, adjuvants for cancer immunotherapy and nanoparticles for cell imaging.

Hydroxyapatite Nanoparticles for Improved Cancer Theranostics.

Beyond their well-known applications in bone tissue engineering, hydroxyapatite nanoparticles (HAp NPs) have also been showing great promise for improved cancer therapy. The chemical structure of HAp NPs offers excellent possibilities for loading and delivering a broad range of anticancer drugs in a sustained, prolonged, and targeted manner and thus eliciting lower complications than conventional chemotherapeutic strategies. The incorporation of specific therapeutic elements into the basic composition of HAp NPs is another approach, alone or synergistically with drug release, to provide advanced anticancer effects such as the capability to inhibit the growth and metastasis of cancer cells through activating specific cell signaling pathways. HAp NPs can be easily converted to smart anticancer agents by applying different surface modification treatments to facilitate the targeting and killing of cancer cells without significant adverse effects on normal healthy cells. The applications in cancer diagnosis for magnetic and nuclear in vivo imaging are also promising as the detection of solid tumor cells is now achievable by utilizing superparamagnetic HAp NPs. The ongoing research emphasizes the use of HAp NPs in fabricating three-dimensional scaffolds for the treatment of cancerous tissues or organs, promoting the regeneration of healthy tissue after cancer detection and removal. This review provides a summary of HAp NP applications in cancer theranostics, highlighting the current limitations and the challenges ahead for this field to open new avenues for research.

Ca19Zn2(PO4)14 Nanoparticles: Synthesis, characterization and its effect on the colonization of Streptococcus mutans on tooth surface

The main cause of tooth decay is the biofilm formation of Streptococcus mutans. This study aimed to investigate the effect of the zinc oxide nanoparticles (ZnO NPs), hydroxyapatite nanoparticles (Ca10(PO4)6(OH)2) (HAP NPs), zinc oxide/hydroxyapatite nanocomposites (ZnO/HAP NCs), and Zn-substituted hydroxyapatite nanoparticles (Ca19Zn2(PO4)14 NPs) on the growth and biofilm formation, bacterial adherence, and the expression of ftf and gtf genes in Streptococcus mutans. The nanostructures were prepared via simple and fast co-precipitation route. Twelve isolates of Streptococcus mutans collected from children with dental caries referred to the dental clinic of Kashan University of Medical Sciences. All S. mutans isolates were susceptible to Ampicillin. The mean MIC for ZnO NPs, HAP NPs, Ca19Zn2(PO4)14, and ZnO/HAP NCs were 118, 260, 70.6, and 994 µg/mL, respectively. All prepared nanostructures significantly reduced biofilm formation at MIC and sub-MIC concentrations (p < 0.01). In biofilm and cell culture treated with nanoparticles, the expression of ftf and gtfC genes decreased. Results were shown that IC50 for the Ca19Zn2(PO4)14 was 8.5, and for non-toxic concentration, was 0.065 µg/mL. The attachment rate to the denture surface and HGF1 cell line treated with the Ca19Zn2(PO4)14 NPs has decreased. The results showed that the Ca19Zn2(PO4)14 NPs has a better effect than the ZnO/HAP NCs. It can therefore be used as a coating on dental surfaces. Investigation of Ca19Zn2(PO4)14 NPs form for covering dental teeth surface recommended in future study.

Hydroxyapatite nanoparticles as novel nano-fertilizer for production of rosemary plants

Nano-fertilizers are new materials produced by means of nanotechnology and may soon replace conventional fertilizers. Nanomaterials including nanoparticles are characterized by rapid absorption and controlled delivery of nutrients in plants. In the current study, hydroxyapatite, i.e., calcium phosphate, nanoparticles (HAP NPs) were developed as a novel phosphorus nano-fertilizer and evaluated for the growth characters, essential oil content, and histological changes in rosemary (Rosmarinus officinalis L.) plants. For comparison, the NPK fertilizer was used. The results showed that compared to the traditional form NPK, nano-HA at 0.5 and 1.0 g/L enhanced the growth character and essential oil production along with its major constituents during both cuts. The levels of rosemary oil components including α-pinene, eucalyptol, camphor, endo-borneol and verbenone were higher in the nano-fertilizer group than in the control group. Furthermore, the highest values of the stem diameter, fiber thickness, phloem tissue thickness, xylem tissue thickness, pith diameter of the stem and the midvein thickness and lamina thickness of the leaf were obtained with nano-fertilizer. In conclusion, the data demonstrate that hydroxyapatite nanoparticles as a nano-fertilizer showed great potential to improve the productivity of rosemary plants. This approach opens a new avenue for exploring nanomaterials as an alternative technology to traditional fertilizers used in medicinal and aromatic plant culture.

ESIPT-active hydroxybenzothiazole-picolinium@CB[7]-HAp NPs based supramolecular sensing assembly for spermine, spermidine and cadaverine: Application in monitoring cancer biomarkers and food spoilage

A three-component supramolecular sensing platform has been developed involving a water-soluble, ESIPT-active benzothiazole based probe (BTPICO), cucurbit[7]uril (CB[7]), and citrate-stabilized hydroxyapatite nanoparticles (HAp NPs) for the rapid and sensitive detection of spermine, spermidine, and cadaverine in aqueous media. Spermine, and spermidine act as biomarkers for early-stage diagnosis of cancer in humans and cadaverine mainly acts as a marker for food spoilage. As per the strategy, BTPICO spontaneously forms a conjugate by electrostatic interaction with the negatively charged surface of HAp NPs and goes to a non-emissive state due to the loss of ESIPT property. In the presence of CB[7], the dye interacts with CB[7] portal and in its shield, the dye turns on its emission. The partially positively charged complex further interacts with the negatively charged surface of HAp NPs to form a strongly emissive three-component sensing assembly. Upon addition of spermine, spermidine or cadaverine, the dye is quickly displaced from CB[7] portal by the much stronger interaction with the biogenic amines and fluorescence is again turned off by forming the non-emissive conjugate (BTPICO-HAp NP). The sensing mechanism was established by DLS, microscopic studies, time-resolved spectroscopy, etc. The supramolecular sensing assembly showed nominal interference from various metal ions, anions, amino acids, and other biogenic amines, and low limits of detection (LODs) of 1.4, 3.3, and 17.2 ppb for spermine, spermidine, and cadaverine, respectively. The practical applicability of this sensing system was demonstrated by spiking spermine and spermidine in human urine, blood serum, and cadaverine in different food samples with very good %recovery, thereby, making this sensing platform suitable for real-time, low-level measurement of spermine, spermidine, and cadaverine.

Microstructure and Mechanical Properties of Inverse Nanocomposite Made from Polylactide and Hydroxyapatite Nanoparticles.

Polymer nanocomposites have been extensively researched for a variety of applications, including medical osteoregenerative implants. However, no satisfactory solution has yet been found for regeneration of big, and so-called critical, bone losses. The requirement is to create a resorbable material which is characterised by optimum porosity, sufficient strength, and elastic modulus matching that of the bone, thus stimulating tissue regrowth. Inverse nanocomposites, where the ceramic content is larger than the polymer content, are a recent development. Due to their high ceramic content, they may offer the required properties for bone implants, currently not met by polymer nanocomposites with a small number of nanoparticles. This paper presents inverse nanocomposites composed of bioresorbable nano crystalline hydroxyapatite (HAP NPs) and polylactide (PLLA), produced by cryomilling and a warm isostatic pressing method. The following compositions were studied: 25%, 50%, and 75% of HAP NPs by volume. The mechanical properties and structure of these composites were examined. It was discovered that 50% volume content was optimal as far as compressive strength and porosity are concerned. The inverse nanocomposite with 50% nanoceramics volume displayed a compressive strength of 99 ± 4 MPa, a contact angle of 50°, and 25% porosity, which make this material a candidate for further studies as a bioresorbable bone implant.

Synthesis, Computational Pharmacokinetics Report, Conceptual DFT-Based Calculations and Anti-Acetylcholinesterase Activity of Hydroxyapatite Nanoparticles Derived From Acorus Calamus Plant Extract.

Over the years, Alzheimer’s disease (AD) treatments have been a major focus, culminating in the identification of promising therapeutic targets. A herbal therapy approach has been required by the demand of AD stage-dependent optimal settings. Present study describes the evaluation of anti-acetylcholinesterase (AChE) activity of hydroxyapatite nanoparticles derived from an Acorus calamus rhizome extract (AC-HAp NPs). The structure and morphology of as-prepared (AC-HAp NPs) was confirmed using powder X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM). The crystalline nature of as-prepared AC-HAp NPs was evident from XRD pattern. The SEM analysis suggested the spherical nature of the synthesized material with an average diameter between 30 and 50 nm. Further, the TEM and HR-TEM images revealed the shape and size of as-prepared (AC-HAp NPs). The interplanar distance between two lattice fringes was found to be 0.342 nm, which further supported the crystalline nature of the material synthesized. The anti-acetylcholinesterase activity of AC-HAp NPs was greater as compared to that of pure HAp NPs. The mechanistic evaluation of such an activity carried out using in silico studies suggested that the anti-acetylcholinesterase activity of phytoconstituents derived from Acorus calamus rhizome extract was mediated by BNDF, APOE4, PKC-γ, BACE1 and γ-secretase proteins. The global and local descriptors, which are the underpinnings of Conceptual Density Functional Theory (CDFT), have been predicted through the MN12SX/Def2TZVP/H2O model chemistry to help in the comprehension of the chemical reactivity properties of the five ligands considered in this study. With the further objective of analyzing their bioactivity, the CDFT studies are complemented with the estimation of some useful computed pharmacokinetics indices, their predicted biological targets, and the ADMET parameters related to the bioavailability of the five ligands are also reported.

Development of Biopolymeric Hybrid Scaffold-Based on AAc/GO/nHAp/TiO2 Nanocomposite for Bone Tissue Engineering: In-Vitro Analysis.

Bone tissue engineering is an advanced field for treatment of fractured bones to restore/regulate biological functions. Biopolymeric/bioceramic-based hybrid nanocomposite scaffolds are potential biomaterials for bone tissue because of biodegradable and biocompatible characteristics. We report synthesis of nanocomposite based on acrylic acid (AAc)/guar gum (GG), nano-hydroxyapatite (HAp NPs), titanium nanoparticles (TiO2 NPs), and optimum graphene oxide (GO) amount via free radical polymerization method. Porous scaffolds were fabricated through freeze-drying technique and coated with silver sulphadiazine. Different techniques were used to investigate functional group, crystal structural properties, morphology/elemental properties, porosity, and mechanical properties of fabricated scaffolds. Results show that increasing amount of TiO2 in combination with optimized GO has improved physicochemical and microstructural properties, mechanical properties (compressive strength (2.96 to 13.31 MPa) and Young’s modulus (39.56 to 300.81 MPa)), and porous properties (pore size (256.11 to 107.42 μm) and porosity (79.97 to 44.32%)). After 150 min, silver sulfadiazine release was found to be ~94.1%. In vitro assay of scaffolds also exhibited promising results against mouse pre-osteoblast (MC3T3-E1) cell lines. Hence, these fabricated scaffolds would be potential biomaterials for bone tissue engineering in biomedical engineering.

Multiscale synergistic toughened pluronic/PMEA/ hydroxyapatite hydrogel laminated aramid soft composites: Puncture resistance and self-healing properties

In order to solve the recycling of the puncture-resistant soft composites, this study constructs a multiscale self-healing gel-fabric soft composite synergistically toughened by Pluronic/PMEA hydrogel, hydroxyapatite nanoparticles (HAP NPs) and aramid fabric. Results show that the gel matrix has a self-healing efficiency of 85% after puncture damage, and the stab resistances are highly positively associated with the toughness of the hydrogel matrix. When toughened by 4% HAP NPs, the spike and knife resistances of soft composites are improved by 132% and 130%, respectively. After being laminated, the composite exhibits a self-repairing efficiency of 52% and still has excellent performance after multiple punctures. At lamination angle of 45° and the gel volume fraction of 45%, the composite has the best puncture resistance properties, and the 37 layers can resist against the E1 stab resistance energy. The synergistic toughened mechanism is due to the interfacial shear strength between the fiber and the gel matrix. Overall, this research provides a novel structural design for the recycling of high-performance puncture-resistant composites.

Novel nanosystems to enhance biological activity of hydroxyapatite against dental caries

This work aimed to study for the first time to our knowledge the influence of the structure of the dental flosses (DF) coated by hydroxyapatite nanoparticles (HAP NPs) on the biological performance of saliva probiotic bacteria (S. salivarius), and human dermal and osteoblast-like cells. We used three types of HAP@DF composites (based on two unwaxed dental flosses - “fluffy” and “smooth”, and one waxed “smooth”) with different morphologies. Obtained composites were characterized from the point of view of their structure, morphological characteristics, elemental and chemical composition.We observed that HAP NPs coated “smooth” dental flosses led to an increase of viability and proliferation of oral cavity probiotic bacteria (Streptococcus salivarius) and human cells (dermal fibroblasts and osteoblast-like). In contrast, the highest viability loss of probiotic bacteria (S. salivarius), fibroblasts, and osteoblast-like cells were observed for “fluffy” unwaxed dental flosses due to high cytotoxicity.Our studies showed that HAP NPs significantly improved the biological properties of “fluffy” dental floss. Pristine “smooth” DFs (waxed and unwaxed), as well as all HAP-coated DFs, induced acceptable biocompatibility toward selected human cells.