Osteoblast Cell Adhesion Research Articles

Development of nanoparticles for delivering recombinant human secretory leukocyte protease inhibitor (rhSLPI) for enhancing human osteoblast differentiation

The global number of elderly people has been increasing and the world can now be considered as an aging society. One of the most concerning health problems in the elderly is a musculoskeletal disease, in which fractures and osteoporosis are the most common problems. The deteriorating bone quality in the elderly is a limitation for treatment and for patient recovery. Several drugs and biomolecules have been studied for enhancing osteoblast properties and differentiation. The secretory leukocyte protease inhibitor (SLPI), which is a serine protease inhibitory protein, has been reported to enhance osteoblast cell adhesion, proliferation, and differentiation. However, the application of SLPI in real clinical settings is limited due to its short half-life in circulation and the fact that it can be destroyed by circulating protease enzymes. Therefore, the application of nanoparticle encapsulation might be of benefit for SLPI delivery. This study aims to fabricate the liposome nanoparticles encapsulating recombinant human SLPI or rhSLPI (rhSLPI-LNPs) for augmenting the half-life and enhancing human osteoblast differentiation. The liposome nanoparticles (LNPs) were fabricated by the thin film hydration method. Encapsulation of rhSLPI was performed by adding 0.33 µg/mL rhSLPI in ultrapure water to the thin film lipid and then rhSLPI-LNPs formed into vesicles. The size and zeta potential of blank-LNPs or rhSLPI-LNPs were measured by scanning electron microscopy (SEM) and dynamic light scattering (DLS). The results showed that the size of both blank-LNPs and rhSLPI-LNPs was approximately 200 nm, and the zeta potentials were −55.6 ± 16.90 mV and −64 ± 7.86 mV, respectively. The rhSLPI encapsulation was confirmed by ELISA. The results showed that liposome nanoparticles could encapsulate rhSLPI. For cytotoxicity, rhSLPI-LNPs treatment did not cause any toxicity to the human osteoblast cell line (hFOB 1.19). In addition, pre-incubation of hFOB 1.19 with rhSLPI-LNPs could significantly enhance osteoblast adhesion when compared with the untreated group.

Synthesis and investigation on microstructural, mechanical features of mesoporous hardystonite/reduced graphene oxide nanocomposite for medical applications.

The use of hardystonite (Ca2ZnSi2O7, HT)-based composites could be one the main strategies to improve mechanical properties closing to natural bone. However, there are a few reports in this regard. Recent findings indicate that graphene is a promising biocompatible additive in ceramic-based composite. Here, we propose a simple approach for the synthesis of porous nano- and microstructured hardystonite/reduced graphene oxide (HT/RGO) composite using a sol-gel method followed by ultrasonic and hydrothermal processes. Integrating GO to the pure HT increased the bending strength and toughness values about 27.59% and 34.33%, respectively. It also allowed the increment of compressive strength and compressive modulus by about 8.18% and 86%, respectively, and improvement in the fracture toughness about 11.8 times compared to pure HT. The formation of HT/RGO nanocomposites with different RGO weight percentages ranging from 0 to 5.0 has been investigated by scanning electron microscopy (SEM) and X-ray diffraction and the efficient incorporation of GO nanosheets into HT nanocomposite as well as the mesoporous structural properties were also confirmed by Raman, FTIR and BET analyses. The cell viability of HT/RGO composite scaffolds was assayed by methyl thiazole tetrazolium (MTT) test in vitro. In this regard, the alkaline phosphatase (ALP) activity and the proliferation rate of mouse osteoblastic cells (MC3T3-E1) on the HT/1wt. % RGO composite scaffold enhanced in comparison with the pure HT ceramic. The adhesion of osteoblastic cells on the 1% wt. HT/RGO scaffold was interesting as well. In addition, the effect of 1% wt. HT/RGO extract on the proliferation of osteoblast human G-292 cells was successfully evaluated and remarkable observations were obtained. All together it can be said that the proposed bioceramic hardystonite/reduced graphene oxide composites can be a promising candidate for designing hard tissue implants.

Effects of Electronic Cigarette E-Liquids on the Adhesion and Growth of Osteoblast Cells

Electronic cigarettes (E-cigarettes) were designed to replace traditional cigarettes to decrease the harmful effects of smoking. The liquid in e-cigarettes contains different chemicals, such as Propylene Glycol (PG) and Vegetable Glycerin (VG), and may contain nicotine. To be more attractive, e-liquids are supplemented with flavorings. Because vaped e-liquids are shown to be damaging to oral tissues, similar effects could occur in the oral cavity with non-vaped e-liquids. We evaluated the effects of non-vaped e-liquid constituents on osteoblast behavior. For this purpose, human osteoblast cells (MG-63) were exposed to e-liquid containing 70% PG -30% VG with and without tobacco flavor and with or without nicotine at 12, 18 mg/mL, or no nicotine content. The e-liquids were used at various concentrations (0, 1, and 5%). To evaluate the effect of the e-liquids on osteoblast morphology and adhesion, optical microscope observations and viable cell counting using trypan blue exclusion were used. Cell growth was also analyzed using the Methyl Thiazol Tetrazolium (MTT) assay, while cytotoxicity was tested by measuring Lactate Dehydrogenase (LDH) levels after cell exposure for 24 h to the e-liquids. Our results show that e-liquids induced significant morphological changes evidenced by round cell forms, with no contact between cells. Adhesion was significantly reduced, particularly in the presence of nicotine. E-liquids at a concentration of 5% significantly reduced osteoblast growth. This effect was observed with both flavored and non-flavored e-liquid with or without nicotine. The decreased osteoblast adhesion and growth after exposure to e-liquid was confirmed by increased levels of LDH. Overall results indicate the potentially harmful effects of e-liquid non-vaped chemicals on bone cells, which could lead to the impairment of bone regeneration and tissue remodeling processes.

Low concentrations of grape seed extract maintain osteoblast morphology, cell adhesion, and mineralization.

The increase in life expectancy has led to a higher incidence of osteoporosis, characterized by an imbalance in bone remodeling. Several drugs are used for its treatment, but most promote undesirable side effects. The present investigation evaluated the effects of two low concentrations of grape seed extract (GSE) rich in proanthocyanidins on MC3T3-E1 osteoblastic cells. The cells were cultured in an osteogenic medium and divided into control (C), 0.1 µg/mL GSE (GSE0.1), and 1.0 µg/mL GSE (GSE1.0) groups to evaluate cell morphology, adhesion, and proliferation, in situ alkaline phosphatase (ALP) detection, mineralization and immunolocalization of osteopontin (OPN). The data obtained were analyzed by statistical tests for a significance of 5%. Cell morphology was maintained with both GSE concentrations, whereas cell adhesion significantly increased within three days in all groups. Cell proliferation increased significantly at seven days of culture, followed by a significant decrease in all experimental periods, with no statistical difference among them. In situ detection of ALP and mineralization increased with time, but within each period, no statistical differences among groups were observed. The expression of osteopontin was distributed regularly with more intensity after 24 hours in the GSE0.1 group. After three days, OPN expression was more intense in the control group, followed by GSE0.1 and GSE1.0 groups. Data obtained suggest that low concentrations of GSE do not affect the morphology and may stimulate the functional activity of osteoblastic cells.

Long-Bone-Regeneration Process in a Sheep Animal Model, Using Hydroxyapatite Ceramics Prepared by Tape-Casting Method.

This study was designed to investigate the effects of hydroxyapatite (HA) ceramic implants (HA cylinders, perforated HA plates, and nonperforated HA plates) on the healing of bone defects, addressing biocompatibility, biodegradability, osteoconductivity, osteoinductivity, and osteointegration with the surrounding bone tissue. The HA ceramic implants were prepared using the tape-casting method, which allows for shape variation in samples after packing HA paste into 3D-printed plastic forms. In vitro, the distribution and morphology of the MC3T3E1 cells grown on the test discs for 2 and 9 days were visualised with a fluorescent live/dead staining assay. The growth of the cell population was clearly visible on the entire ceramic surfaces and very good osteoblastic cell adhesion and proliferation was observed, with no dead cells detected. A sheep animal model was used to perform in vivo experiments with bone defects created on the metatarsal bones, where histological and immunohistochemical tissue analysis as well as X-ray and CT images were applied. After 6 months, all implants showed excellent biocompatibility with the surrounding bone tissue with no observed signs of inflammatory reaction. The histomorphological findings revealed bone growth immediately over and around the implants, indicating the excellent osteoconductivity of the HA ceramic implants. A number of islands of bone tissue were observed towards the centres of the HA cylinders. The highest degree of biodegradation, bioresorption, and new bone formation was observed in the group in which perforated HA plates were applied. The results of this study suggest that HA cylinders and HA plates may provide a promising material for the functional long-bone-defect reconstruction and further research.

Strontium/zinc phytate-based self-assembled monolayers on titanium surfaces enhance osteogenesis and antibacterial performance in vitro

The accumulation of bacteria over implant surfaces is still the first cause of failure, and the development of antimicrobial surfaces constitutes a first line in implant research. Besides, the durability and mechanical performance of implants, in special in the dental area, are mainly determined by their osseointegration capacity into the maxillofacial bone and the appearance of infections. Consequently, implant osseointegration and infection prophylaxis remain as big challenges to attain so a huge investigation is being developed on the production of bioactive surfaces to achieve improvements in these aspects. In this work we propose the functionalization of titanium surfaces (Ti Cp) with self-assembled monolayers (SAMs) of bioactive organophosphate compounds: phytic acid (Ti-PA) and its metallic phytate derivatives bearing Sr2+ and/or Zn2+ (Ti-SrPhy, Ti-ZnPhy and Ti-SrPhy/ZnPhy) which exhibited tunable in vitro osteogenic, antimicrobial and antioxidant properties in a previous work. Thus, phytate compounds are chemically anchored onto Ti discs through a simple procedure consisting of a condensation reaction promoted by heat treatment. EDS and XPS spectroscopies confirm the obtaining of the modified surfaces and the topographic properties and wettability analysed by SEM, AFM, profilometry and contact angle measurements, respectively, are explored. Additionally, phytate-SAMs do not release any cytotoxic compound after 14 days and stimulate in vitro adhesion and proliferation of human osteoblast cells after 14 days of culture. The osteogenic ability of the modified surfaces evaluated by the quantification of ALP activity and matrix mineralization degree shows a significant improvement with respect to unmodified surfaces. Furthermore, the antimicrobial activity of phytate-SAMs against Streptococcus mutans cultures is evaluated. The count of viable cells and the quantification of produced biofilm are significantly reduced by all phytate-SAMs groups (p < 0.001). Cell membrane integrity studies by LIVE/DEAD staining and SEM imaging confirm a decreased viability of adhered bacteria when phytate-based surfaces are tested, due to a disruption in the function and permeability of the cell membrane. Therefore, phytate-SAMs exhibit suitable in vitro features suggesting their promising potential as bioactive coatings of dental implants.

Regulation of TiO2 nanoarrays on titanium implants for enhanced osteogenic activity and immunomodulation

The surface topography of implants plays a major role in osteogenesis and immunomodulation. In this study, three types of TiO2 nanoarrays including nanorod arrays with a diameter of 45 nm (TiO2-N), nanorod arrays with a diameter of 60 nm (TiO2-N N), and nanocone arrays (TiO2-NW) are prepared on titanium and the behavior of bone marrow stromal cells (BMSCs) and polarization of macrophages are studied. Compared to the planar titanium control, TiO2 nanoarrays facilitate osteogenesis of BMSCs and stimulate the pro-healing M2 phenotype. However, adhesion, spreading, proliferation, and osteogenic differentiation of BMSCs are more pronounced on TiO2-N N than both TiO2-N and TiO2-NW. TiO2-NN also produces the best immune microenvironment, while TiO2-NW is more favorable than TiO2-NN from the viewpoint of cell adhesion and spreading of osteoblasts.

Influence of the roughness of dental implants obtained by additive manufacturing on osteoblastic adhesion and proliferation: A systematic review

ObjectiveCritically analyzed the existing literature to answer the question "What is the influence of roughness of surfaces for dental implants obtained by additive manufacturing compared to machined on osteoblastic cell adhesion and proliferation?" DesignThis systematic review followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the Open Science Framework. The personalized search strategy was applied to Embase, Pub Med, Scopus, and Science Direct databases and Google Scholar and ProQuest grey literature. The selection process was carried out in two stages independently by two reviewers according to the eligibility criteria. The risk of bias was analyzed using a checklist of important parameters to be considered. ResultsWhen applying the search strategy on databases 223 articles were found, after removing the duplicates, 171 were analyzed by title and abstract of which 25 were selected for full reading, of these, 6 met the eligibility criteria. 2 studies were included from the reference list totaling 8 articles included in this systematic review and none were included from the Grey Literature. 7 had a low risk of bias and 1 moderate. Conclusions1) Roughness is a property that must be analyzed and correlated with the chemical composition, intrinsic to the alloy and resulting from the surface treatment; morphology of topographic peaks and valleys; printing technique and its parameters; 2) Need for more studies on the biomolecular level to elucidate the mechanism by which the roughness and the morphology of topographical peaks and valleys descriptive of roughness influence osteoblastic adhesion and proliferation.

Development and Characterization of Functional Polylactic Acid/Chitosan Porous Scaffolds for Bone Tissue Engineering.

In this study, we developed and characterized various open-cell composite scaffolds for bone regeneration. These scaffolds were made from Polylactic acid (PLA) as the scaffold matrix biopolymeric phase, and chitosan (CS) and chitosan-grafted-PLA (CS-g-PLA) copolymer as the dispersed biopolymeric phase. As a first step, successful grafting of PLA onto CS backbone was executed and confirmed by both FTIR and XPS. Mechanical characterization confirmed that adding CS or CS-g-PLA to the intrinsically rigid PLA made their corresponding PLA/CS and PLA/CS-g-PLA composite scaffolds more flexible under compression. This flexibility was higher for the latter due to the improved compatibility between PLA and CS-g-PLA copolymer. The hydrolytic stability of both PLA/CS and PLA/CS-g-PLA composite scaffolds inside phosphate-buffered saline (PBS) solution, as well as MG-63 osteoblast cell adhesion and proliferation inside both scaffolds, were characterized. The corresponding results revealed that PLA/CS composite scaffolds showed hydrolytic degradation due to the cationic properties of CS. However, modified PLA/CS-g-PLA scaffolds were hydrolytically stable due to the improved interfacial adhesion between the PLA matrix and CS-g-PLA copolymer. Finally, biological characterization was done for both PLA/CS and PLA/CS-g-PLA composite scaffolds. Contrarily to what was observed for uncompatibilized PLA/CS scaffolds, compatibilized PLA/CS-g-PLA scaffolds showed a high MG-63 osteoblast cell proliferation after three and five days of cell culture. Moreover, it was observed that cell proliferation increased with CS-g-PLA content. This suggests that the PLA/CS-g-PLA composite scaffolds could be a potential solution for bone regeneration.

Electrostatic Analysis of Bioactivity of Ti-6Al-4V Hydrophilic Surface with Laser Textured Micro-Square Convexes.

At solid-liquid interfaces, charged particles within the electric double layer (EDL) are acted on by the electrostatic force, which may affect cell absorption and surface wettability. In this study, a model of the electrostatic force and surface tension of textured surfaces was presented. Then, the growth and adhesion of Murine osteoblasts (MC3T3-E1) cells on laser-ablated micro-square-textured Ti-6Al-4V surfaces were studied to demonstrate the use of a laser-processed texture to effectively improve bioactivity. Three different micro-square-textured hydrophilic surfaces, presenting lower contact angles of 19°, 22.5°, and 31.75° compared with that of a smooth surface (56.5°), were fabricated using a fiber-optic laser. Cellular morphology and initial cell attachment were analyzed by field emission scanning electron microscopy (SEM) and fluorescence microscopy, respectively. The results show that the electrostatic force not only made the textured surface more hydrophilic but also made the cells tend to adhere to the edges and corners of the protruding convexes. Cell morphology analysis also showed that cells would prefer to grow at the edges and corners of each micro-square convex protrusion. The laser-treated surfaces were more conducive to rapid cell growth and adhesion, and cells were preferentially attached on the hydrophilic-textured surfaces. Electrostatic force may be an important factor in effectively improving the bioactivity of Ti-6Al-4V surfaces, and the presence of more surface grooves would be more conducive to improving the bioactivity of cells.

Influence of Dental Implant Surface Modifications on Osseointegration and Biofilm Attachment

Dental implants have been widely applied in partially and fully edentulous patients and have shown predictable clinical outcomes, but there are still many cases of implant failures, such as osseointegration failure and peri-implant inflammation. To improve the success rate of implants, especially in improving osseointegration and antibacterial performance, various methods of implant surface modification have been applied. Surface modification methods covered include sandblasting with large-grit corundum and acid etched (SLA), plasma spraying, plasma immersion ion implantation (PIII), sputter-deposition, selective laser melting (SLM), anodic oxidation, microarc oxidation, sol-gel coating, alkaline heat treatment (AH) and Layer-by-Layer (LBL) self-assembly. This review comprehensively summarizes the influence of each method on osseointegration and biofilm attachment. The mechanical, chemical and biological disadvantages of these methods are involved. Besides, the mechanisms behind such techniques as increasing surface roughness to expand superficial area and enhance the adhesion of osteoblastic cells are discussed.

Silk-Cellulose Nanocrystal Composite Coatings for Enhanced Corrosion Protection and Cytocompatibility

The clinical application of magnesium (Mg)-based alloys as biodegradable orthopedic implants is highly restricted because of their rapid corrosion rate in the physiological environment [1]. Polymeric coatings have been recognized as one of the most effective methods to tailor the corrosion rate of Mg alloys without changing their bulk properties, while providing them with other functionalities such as enhanced biocompatibility [2]. In this study, a composite polymeric coating based on silk fibroin (SF) and cellulose nanocrystal (CNC) was fabricated on AZ31 Mg alloy to enhance its corrosion resistance and cytocompatibility for biodegradable bone implant application. The coating was prepared by drop-cast method on AZ31 Mg alloy and fully characterized by various physiochemical techniques. The corrosion resistance of the coating and the effect of CNC inclusion on the corrosion protection performance of the coating were investigated through extensive electrochemical techniques (open circuit potential, polarization test, and electrochemical impedance spectroscopy) as well as in vitro immersion tests. In addition, the cytocompatibility of the coating in terms of cellular toxicity and adhesion was assessed toward human fetal osteoblast cells. SEM images revealed the formation of a defect-free and uniform SF-CNC coating with a thickness of 11.2 ± 2.5 µm on AZ31 alloy. The results of the electrochemical corrosion and in vitro immersion tests clearly demonstrated an enhanced corrosion resistance of the SF coating after the incorporation of CNCs. Compared to the unmodified Mg alloy, the SF-CNC coated AZ31 exhibited a remarkably improved cytocompatibility with a viability of 114% and excellent adhesion and spreading of human fetal osteoblast cells onto the coating surface. The findings of this work highlight the great potential of SF and CNC as bio-based nature-derived anticorrosive nanofillers for fabrication of protective and biocompatible coatings on Mg-based biodegradable orthopedic implants.

Safe-by-Design Antibacterial Peroxide-Substituted Biomimetic Apatites: Proof of Concept in Tropical Dentistry.

Bone infections are a key health challenge with dramatic consequences for affected patients. In dentistry, periodontitis is a medically compromised condition for efficient dental care and bone grafting, the success of which depends on whether the surgical site is infected or not. Present treatments involve antibiotics associated with massive bacterial resistance effects, urging for the development of alternative antibacterial strategies. In this work, we established a safe-by-design bone substitute approach by combining bone-like apatite to peroxide ions close to natural in vivo oxygenated species aimed at fighting pathogens. In parallel, bone-like apatites doped with Ag+ or co-doped Ag+/peroxide were also prepared for comparative purposes. The compounds were thoroughly characterized by chemical titrations, FTIR, XRD, SEM, and EDX analyses. All doped apatites demonstrated significant antibacterial properties toward four major pathogenic bacteria involved in periodontitis and bone infection, namely Porphyromonas gingivalis (P. gingivalis), Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), Fusobacterium nucleatum (F. nucleatum), and S. aureus. By way of complementary tests to assess protein adsorption, osteoblast cell adhesion, viability and IC50 values, the samples were also shown to be highly biocompatible. In particular, peroxidated apatite was the safest material tested, with the lowest IC50 value toward osteoblast cells. We then demonstrated the possibility to associate such doped apatites with two biocompatible polymers, namely gelatin and poly(lactic-co-glycolic) acid PLGA, to prepare, respectively, composite 2D membranes and 3D scaffolds. The spatial distribution of the apatite particles and polymers was scrutinized by SEM and µCT analyses, and their relevance to the field of bone regeneration was underlined. Such bio-inspired antibacterial apatite compounds, whether pure or associated with (bio)polymers are thus promising candidates in dentistry and orthopedics while providing an alternative to antibiotherapy.

Tantalum nanoparticles reinforced polyetheretherketone coatings on titanium substrates: Bio-tribological and cell behaviour

As a biomaterial for bone repair, the application of polyetheretherketone (PEEK) has been limited by its poor wear resistance and cell behaviour. Inspired by the double ‘soft-hard’ phase structure, tantalum (Ta)/PEEK composite coating was fabricated on a titanium surface. All composite coatings had a lower friction coefficient and wear resistance under fetal bovine serum conditions. The adhesion, proliferation, and osteogenic differentiation of rat bone osteoblastic cells (MC3T3-E1) and mononuclear macrophage cells (RAW264.7) on the Ta/PEEK composite coating was enhanced. In particular, composite coatings effectively reduced inflammatory markers, with cytokines TGF-β and IL-10 released. As a result, titanium alloys with Ta reinforced PEEK coatings could exhibit improved bioactivity and tribology.

Complex effects of Mg-biomaterials on the osteoblast cell machinery: A proteomic study.

The cell-biomaterial interface is highly complex; thousands of molecules and many processes participate in its formation. Growing demand for improved biomaterials has highlighted the need to understand the structure and functions of this interface. Proteomic methods offer a viable alternative to the traditional in vitro techniques for analyzing such systems. Magnesium is a promoter of cell adhesion and osteogenesis. Here, we used the LC-MS/MS to compare the protein expression profiles of human osteoblasts (HOb) exposed to sol-gel coatings without (MT) and with Mg (MT1.5Mg) for 1, 3, and 7days. PANTHER, DAVID, and IPA databases were employed for protein identification and data analysis. Confocal microscopy and gene expression analysis were used for further characterization. Exposure to MT1.5Mg increased the HOb cell area and the expression of SP7, RUNX2, IBP3, COL3A1, MXRA8, and FBN1 genes. Proteomic analysis showed that MT1.5Mg affected the early osteoblast maturation (PI3/AKT, mTOR, ERK/MAPK), insulin metabolism, cell adhesion (integrin, FAK, actin cytoskeleton regulation) and oxidative stress pathways. Thus, the effects of Mg on cell adhesion and osteogenesis are rather complex, affecting several pathways rather than single processes. Our analysis also confirms the potential of proteomics in biomaterial characterization, showing a good correlation with in vitro results.

Tailoring the biologic responses of 3D printed PEEK medical implants by plasma functionalization

ObjectiveThe objective of this study was to determine the effect of two plasma surface treatments on the biologic responses of PEEK medical implants manufactured by fused filament fabrication (FFF) 3D printing technology. MethodsThis study created standard PEEK samples using an FFF 3D printer. After fabrication, half of the samples were polished to simulate a smooth PEEK surface. Then, argon (Ar) or oxygen (O2) plasma was used to modify the bioactivity of FFF 3D printed and polished PEEK samples. Scanning electron microscopy (SEM) and a profilometer were used to determine the microstructure and roughness of the sample surfaces. The wettability of the sample surface was assessed using a drop shape analyzer (DSA) after plasma treatment and at various time points following storage in a closed environment. Cell adhesion, metabolic activity, proliferation, and osteogenic differentiation of SAOS-2 osteoblasts were evaluated to determine the in vitro osteogenic activity. ResultsSEM analysis revealed that several spherical nanoscale particles and humps appeared on sample surfaces following plasma treatment. The wettability measurement demonstrated that plasma surface treatment significantly increased the surface hydrophilicity of PEEK samples, with only a slight aging effect found after 21 days. Cell adhesion, spreading, proliferation, and differentiation of SAOS-2 osteoblasts were also up-regulated after plasma treatment. Additionally, PEEK samples treated with O2 plasma demonstrated a higher degree of bioactivation than those treated with Ar. SignificancePlasma-modified PEEK based on FFF 3D printing technology was a feasible and prospective bone grafting material for bone/dental implants.

Utilization of Polymethyl Methacrylate and Hydroxyapatite Composite as Biomaterial Candidate for Porous Trabecular Dental Implant Fixture Development: A Narrative Review

Polymethyl Methacrylate (PMMA) and Hydroxyapatite (HA) utilization as single materials are rarely used as dental implant materials. There is a promising hope by combining these two materials as a dental implant fixture. Nevertheless, there is a limited information of PMMA/HA composite utilization as dental implant material. The aims of this narrative review is to describe the potential of PMMA/HA composite utilization as biomaterial candidate for porous trabecular dental implant fixture development. This narrative review finds the potential of PMMA/HA composite as biomaterial candidate for porous trabecular dental implant. The keywords "Biomaterial," "Dental Implant," "Hydroxyapatite," "Osseointegration," and "Polymethyl Methacrylate" were used in a web-based search of PubMed, NCBI, Scopus, ScienceDirect, and ResearchGate databases. PMMA is non-toxic, cost-effective, biocompatible, simple to manipulate, and has strong mechanical properties in the oral cavity. Furthermore, osteoblastic cell adhesion, development, and differentiation are aided by the use of HA as a biomaterial to induce bone formation. Nonetheless, due to its rapid absorption and degradation, single HA is seldom used as a dental implant material. Developing dental implant composite has been extensively studied, among them are the fabrication of PMMA/HA. PMMA/HA has fairly good physical characteristics with a compressive strength, good bioaffinity properties, biocompatible with bone cells. The osteoconductivity of HA enhance the bioactivity of the composite materials, thus making the dental implant to have an excellent osseointegration. We propose that there is a possibility of utilization of PMMA/HA composite as biomaterial candidate for porous trabecular dental implant fixture.

Bioactive Cellulose Acetate Electrospun Mats as Scaffolds for Bone Tissue Regeneration.

In the last decades, cell-based approaches for bone tissue engineering (BTE) have relied on using models that cannot replicate the complexity of the bone microenvironment. There is an ongoing amount of research on scaffold development responding to the need for feasible materials that can mimic the bone extracellular matrix (ECM) and aid bone tissue regeneration (BTR). In this work, a porous cellulose acetate (CA) fiber mat was developed using the electrospinning technique and the mats were chemically modified to bioactivate their surface and promote osteoconduction and osteoinduction. The mats were characterized using FTIR and SEM/EDS to validate the chemical modifications and assess their structural integrity. By coupling adhesive peptides KRSR, RGD, and growth factor BMP-2, the fiber mats were bioactivated, and their induced biological responses were evaluated by employing immunocytochemical (ICC) techniques to study the adhesion, proliferation, and differentiation of premature osteoblast cells (hFOB 1.19). The biological assessment revealed that at short culturing periods of 48 hours and 7 days, the presence of the peptides was significant for proliferation and adhesion, whereas at longer culture times of 14 days, it had no significant effect on differentiation and maturation of the osteogenic progenitor cells. Based on the obtained results, it is thus concluded that the CA porous fiber mats provide a promising surface morphology that is both biocompatible and can be rendered bioactive upon the addition of osteogenic peptides to favor osteoconduction leading to new tissue formation.

Mg-1Ca alloy intramedullary nailing influence on bone callus formation and on vital organs functions, as an alternative to bioplastics

Magnesium alloys represent a new research direction in the field of orthopedic resorbable metal materials, because it has several important properties that recommend it as an excellent resorbable biomaterial for implants. From in vitro studies, Magnesium has osteoconductive properties, promoting the formation of new bone by stimulating the adhesion of osteoblastic cells, this leading to the idea that it will induce formation of hard callous at fracture site. The present study followed the in vivo evaluation of the biodegradation of pins made of Mg-1Ca alloy introduced centromedulary in rabbit tibiae, with previously induced experimental fractures. The influence of the biodegradation process on the formation of the bone callus was evaluated through radiological images and histopathological examinations. At the same time, we evaluated the function of vital organs through histopathological examinations and blood tests. We chose intramedulary nailing (IMN) with pins, because in orthopaedic surgery this is the golden standard for fractures of tibia or femur. In the radiological images obtained, we notice callus formation at the level of the experimental fracture at 6 weeks after surgery. The histological sections made from the samples collected from the fracture zone adjacent to the Mg1Ca alloy implant, confirm the formation of the bony callus. The trichrome Masson sections show a normal bone development with newly formed bone tissue at the tissue - alloy interface. In the sections harvested from the vital organs, no pathological changes are observed. These observations suggest that the biodegradation process of the Mg-1Ca alloy do not interfere negatively with the biological process of bone formation, allowing the formation of the bone callus and do not confirm the suspicion of pathological changes induced by systemically released corrosion products and gas embolism in vital organs.

Electrophoretic deposited boron nitride nanosheets-containing chitosan-based coating on Mg alloy for better corrosion resistance, biocompatibility and antibacterial properties

To reduce the degradation of magnesium alloy, improve its antibacterial activity, and fulfil specific requirements for bone implant material applications, a chitosan (CS)/boron nitride nanosheet (BNNS) composite coating was constructed on the surface of Mg–Zn–Y–Nd–Zr alloy via electrodeposition. The results show that BNNS was uniformly embedded and significantly changed the morphology and roughness of the CS coating. Electrochemical and immersion tests suggest that the CS–BNNS composite coating can effectively provide a long-term protection to the substrate. The antibacterial activity results show that BNNS significantly improved the antibacterial activity of the CS coating against E. coli and S. aureus, and verified the sterilisation mechanism of BNNS in contact with bacterial membranes. Meanwhile, cytocompatibility tests showed that the CS–BNNS coating has no adverse effect on the adhesion and proliferation of mouse osteoblasts cells. Thus, the fabricated CS–BNNS composite coating could be a promising application in surface modification for Mg-based bone implants.