UV Light-Generated Superhydrophilicity of a Titanium Surface Enhances the Transfer,Diffusion and Adsorption of Osteogenic Factors from a Collagen Sponge

It is a significant challenge for a titanium implant, which is a bio-inert material, to recruit osteogenic factors, such as osteoblasts, proteins and blood effectively when these are contained in a biomaterial. The objective of this study was to examine the effect of ultraviolet (UV)-treatment of titanium on surface wettability and the recruitment of osteogenic factors when they are contained in an atelocollagen sponge. UV treatment of a dental implant made of commercially pure titanium was performed with UV-light for 12 min immediately prior to the experiments. Superhydrophilicity on dental implant surfaces was generated with UV-treatment. The collagen sponge containing blood, osteoblasts, or albumin was directly placed on the dental implant. Untreated implants absorbed only a little blood from the collagen sponge, while the UV-treated implants absorbed blood rapidly and allowed it to spread widely, almost over the entire implant surface. Blood coverage was 3.5 times greater for the UV-treated implants (p < 0.001). Only 6% of the osteoblasts transferred from the collagen sponge to the untreated implants, whereas 16% of the osteoblasts transferred to the UV-treated implants (p < 0.001). In addition, a weight ratio between transferred albumin on the implant and measured albumin adsorbed on the implant was 17.3% in untreated implants and 38.5% in UV-treated implants (p < 0.05). These results indicated that UV treatment converts a titanium surface into a superhydrophilic and bio-active material, which could recruite osteogenic factors even when they were contained in a collagen sponge. The transfer and subsequent diffusion and adsorption efficacy of UV-treated titanium surfaces could be useful for bone formation when titanium surfaces and osteogenic factors are intervened with a biomaterial.     

Orientational behaviors of silk fibroin hydrogels

In this study, a novel shear‐induced silk fibroin (SF) hydrogel with three‐dimensional (3D) anisotropic and oriented gel skeleton/network morphology is presented. Amphipathic anionic and nontoxic sodium surfactin is blended with the SF to decrease its gelation time during the mechanical shearing process. The fibroin/surfactin blended solutions undergo a facial shearing process to accomplish a sol–gel transition within 1 hour. The dynamic sol–gel transition kinetic analysis, gel skeleton/network morphology, and mechanical property measurements are determined in order to visualize the fibroin/surfactin sol–gel transition during the shearing process and its resulting hydrogel. The results demonstrate that there is significant β‐sheet assembly from random coil conformations in the fibroin/surfactin blended system during the facile shearing process. The SF β‐sheets further transform into a fibrous large‐scale aggregation with orientational and parallel arrangements to the shearing direction. The shear‐induced fibroin/surfactin hydrogel exhibits notable anisotropic and oriented 3D skeleton/network morphology and a significant mechanical compressive strength in proportion to the shearing stress, compared with the control fibroin/surfactin hydrogel undergoing no shearing process. Due to its oriented gel skeleton/network structure and significantly enhanced mechanical properties, the shear‐induced fibroin/surfactin gel may be suitable as a biomaterial in 3D oriented tissue regeneration, including for nerves, the cultivation of bone cells, and the repair of defects in muscle and ligament tissues. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45050.     

A comprehensive review on biocompatible thin films for biomedical application

Thin films have emerged as an ideal surface treatment to the permanent implant materials to enhance properties such as biodegradation resistance, better mechanical strengths and biocompatibility. A perfect implant ought to have the ability of resistance to degradation, stimulate osseointegration, prevent bacterial adhesion, and decrease prosthetic infection. The clinical success of implants depends on the interaction of cells with material surfaces, which is an essential factor. Recent development in biomaterials has brought a variety of coatings on biomaterial to overcome these issues. The coatings impart biocompatibility, better mechanical property, and bioactivity to the biomaterial. In this review, the recent trends in surface modification by thin films of implants have been discussed in detail.     

Calcium phosphate based ceramic with a resorbable phase and low sintering temperature

The use of glasses with eutectic compositions in the system CaO-P₂O₅ as a sintering aid and as a source of a resorbable phase for obtaining a composite biomaterial for bone implants is examined. The use of such glass has made it possible not only to lower the sintering temperature by realization of the mechanism of liquid-phase sintering but also to form a ceramic material possessing bioresorbability. The material obtained consists of calcium hydroxyapatite, vitlokite, and calcium pyrophosphate phases. __________ Translated from Steklo i Keramika, No. 7, pp. 19–24, July, 2007.     

Calcium Pyrophosphate Dihydrate Crystals Increase the Granulocyte/Monocyte Progenitor (GMP) and Enhance Granulocyte and Monocyte Differentiation In Vivo

Calcium pyrophosphate dihydrate (CPPD) crystals are formed locally within the joints, leading to pseudogout. Although the mobilization of local granulocytes can be observed in joints where pseudogout has manifested, the mechanism of this activity remains poorly understood. In this study, CPPD crystals were administered to mice, and the dynamics of splenic and peripheral blood myeloid cells were analyzed. As a result, levels of both granulocytes and monocytes were found to increase following CPPD crystal administration in a concentration-dependent manner, with a concomitant decrease in lymphocytes in the peripheral blood. In contrast, the levels of other cells, such as dendritic cell subsets, T-cells, and B-cells, remained unchanged in the spleen, following CPPD crystal administration. Furthermore, an increase in granulocytes/monocyte progenitors (GMPs) and a decrease in megakaryocyte/erythrocyte progenitors (MEPs) were also observed in the bone marrow. In addition, CPPD administration induced production of IL-1β, which acts on hematopoietic stem cells and hematopoietic progenitors and promotes myeloid cell differentiation and expansion. These results suggest that CPPD crystals act as a “danger signal” to induce IL-1β production, resulting in changes in course of hematopoietic progenitor cell differentiation and in increased granulocyte/monocyte levels, and contributing to the development of gout.     

Antibacterial Titanium Implants Biofunctionalized by Plasma Electrolytic Oxidation with Silver,Zinc, and Copper: A Systematic Review

Patients receiving orthopedic implants are at risk of implant-associated infections (IAI). A growing number of antibiotic-resistant bacteria threaten to hamper the treatment of IAI. The focus has, therefore, shifted towards the development of implants with intrinsic antibacterial activity to prevent the occurrence of infection. The use of Ag, Cu, and Zn has gained momentum as these elements display strong antibacterial behavior and target a wide spectrum of bacteria. In order to incorporate these elements into the surface of titanium-based bone implants, plasma electrolytic oxidation (PEO) has been widely investigated as a single-step process that can biofunctionalize these (highly porous) implant surfaces. Here, we present a systematic review of the studies published between 2009 until 2020 on the biomaterial properties, antibacterial behavior, and biocompatibility of titanium implants biofunctionalized by PEO using Ag, Cu, and Zn. We observed that 100% of surfaces bearing Ag (Ag-surfaces), 93% of surfaces bearing Cu (Cu-surfaces), 73% of surfaces bearing Zn (Zn-surfaces), and 100% of surfaces combining Ag, Cu, and Zn resulted in a significant (i.e., >50%) reduction of bacterial load, while 13% of Ag-surfaces, 10% of Cu-surfaces, and none of Zn or combined Ag, Cu, and Zn surfaces reported cytotoxicity against osteoblasts, stem cells, and immune cells. A majority of the studies investigated the antibacterial activity against S. aureus. Important areas for future research include the biofunctionalization of additively manufactured porous implants and surfaces combining Ag, Cu, and Zn. Furthermore, the antibacterial activity of such implants should be determined in assays focused on prevention, rather than the treatment of IAIs. These implants should be tested using appropriate in vivo bone infection models capable of assessing whether titanium implants biofunctionalized by PEO with Ag, Cu, and Zn can contribute to protect patients against IAI.     

Dispersion polymerization of uniform cross‐linked polystyrene microspheres in butan‐1‐ol

Butan‐1‐ol can be used as the solvent in the synthesis of poly(styrene‐co‐divinylbenzene‐co‐acrylic acid) microspheres by dispersion polymerization of a mixture of styrene, divinylbenzene (DVB), and acrylic acid (AA). Varying the proportion of the crosslinker DVB affects the size distribution and particle morphology profoundly, with 0.5–1.0% w/w producing spherical particles, whereas 2.0% w/w DVB produces irregular, concave morphologies. Varying the amount of AA from 5–7% w/w increases the average diameter of the spherical particles, whereas 9% w/w AA results in ovoid particles with dimpled surface morphology. In an optimized synthesis using 1.0% w/w DVB and 5% AA, uniform polymer microspheres with an average diameter of 0.8 µm and a coefficient of variation (CV) of diameter of 8.2% are produced. The use of a medium‐polarity solvent, such as butan‐1‐ol, as the solvent for dispersion polymerization will facilitate the incorporation of non‐polar moieties, such as organically‐passivated quantum dots, into the polymer during synthesis. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43103.     

Exploring the Biomaterial-Induced Secretome: Physical Bone Substitute Characteristics Influence the Cytokine Expression of Macrophages

In addition to their chemical composition various physical properties of synthetic bone substitute materials have been shown to influence their regenerative potential and to influence the expression of cytokines produced by monocytes, the key cell-type responsible for tissue reaction to biomaterials in vivo. In the present study both the regenerative potential and the inflammatory response to five bone substitute materials all based on β-tricalcium phosphate (β-TCP), but which differed in their physical characteristics (i.e., granule size, granule shape and porosity) were analyzed for their effects on monocyte cytokine expression. To determine the effects of the physical characteristics of the different materials, the proliferation of primary human osteoblasts growing on the materials was analyzed. To determine the immunogenic effects of the different materials on human peripheral blood monocytes, cells cultured on the materials were evaluated for the expression of 14 pro- and anti-inflammatory cytokines, i.e., IL-6, IL-10, IL-1β, VEGF, RANTES, IL-12p40, I-CAM, IL-4, V-CAM, TNF-α, GM-CSF, MIP-1α, Il-8 and MCP-1 using a Bio-Plex^® Multiplex System. The granular shape of bone substitutes showed a significant influence on the osteoblast proliferation. Moreover, smaller pore sizes, round granular shape and larger granule size increased the expression of GM-CSF, RANTES, IL-10 and IL-12 by monocytes, while polygonal shape and the larger pore sizes increased the expression of V-CAM. The physical characteristics of a bone biomaterial can influence the proliferation rate of osteoblasts and has an influence on the cytokine gene expression of monocytes in vitro. These results indicate that the physical structure of a biomaterial has a significant effect of how cells interact with the material. Thus, specific characteristics of a material may strongly affect the regenerative potential in vivo.     

Polyhydroxy propionate-co-hydroxy dodecanoate-co-hydroxy octadecanoate for in vitro cell culture

This study is novel to report the utilization of molasses for the production of polyhydroxy propionate-co-hydroxy dodecanoate-co-hydroxy octadecanoate from Pseudomonas sp. LDC-5 as prospective biomaterial. Thermal analysis revealed its potential for thermal permanence and melt processing. 3T3 fibroblasts were cultured on these different scaffolds and their proliferation was compared. Giemsa and acridine orange/ethidium bromide staining revealed that there was no distinct change in morphology. Polyhydroxyalkanoate:poly ethylene glycol blend was found to be the most promising for extracellular matrix secretion, a key thrust function of 3D culture. Lactate dehydrogenase assay indicated the membrane integrity. DNA fragmentation analysis showed that the scaffold did not damage DNA. Thus the prepared scaffold can serve as a promising biomaterial.     

Polymer-Encapsulated Phosphor Particles for In Vivo Phosphor Luminescence Applications

Phosphor thermometry is a highly sensitive, rapid, and portable thermal sensing technique that offers advantages over traditional contact-based thermometry techniques. Phosphor particles would however require an encapsulation medium that is biocompatible and yet optically transparent to permit optical access to the embedded phosphor particles. Here, phosphor-doped silicone implants with varying concentrations were prepared and tested in a rat model. Results indicate that such phosphor-doped polymeric implants are stable, produce a detectable signal, and demonstrate the feasibility of phosphor thermometry as a noninvasive remote thermal sensing technique for in vivo applications. Also, encapsulation in silicone did not lead to significant attenuation of the incoming signal.     

Effects of polydimethylsiloxane grafting on the calcification,physical properties,and biocompatibility of polyurethane in a heart valve

Segmented polyurethane (PU) has proven to be the best biomaterial for artificial heart valves, but the calcification of polyurethane surfaces causes serious problems in long‐term implants. This work was undertaken to evaluate the effects of polydimethylsiloxane (PDMS) grafting on the calcification, biocompatibility, and blood compatibility of polyurethane. A grafted polyurethane film was compared with virgin polyurethane surfaces. Physical properties of the samples were examined using different techniques. The hydrophobicity of the polyurethane films increased as a result of silicone modification. The effects of surface modification of polyurethane films on their calcification and fibroblast cell (L 929) and platelet behavior were evaluated in vitro. Fourier transform infrared spectroscopy indicated the direct involvement of the polyether soft segments of the polymer in the calcification process. Scanning electron microscopy of films indicated that grafting of silicone rubber to the surface of polyurethane successfully prevented the calcification process. The morphology of fibroblast cells that adhered to the PU films and modified films was similar to that of controls and showed the same proliferation. On the other hand, grafting PDMS onto PU did not affect the amount of platelets that adhered to the polyurethane surfaces. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 758–766, 2005     

Physical,mechanical, and biocompatibility evaluation of three different types of silicone rubber

Silicone rubber as a valuable biomaterial is widely used in medical applications, but its surface properties and low wettability make serious problems in long‐term implants. This work was undertaken to evaluate the biocompatibility of modified silicone rubber using two different techniques. A blend of poly(acrylamide) and silicone rubber was compared with virgin silicone surfaces as well as with those modified by laser treatment. Physical and mechanical properties of the samples were examined using different techniques. The hydrophilicity of the silicone rubber increased with increasing hydrogel content and decreased as a result of laser treatment. Both fibroblast cell (L929) and platelet behavior in contact with these surfaces were evaluated in vitro. The morphology of fibroblast cells that adhered to the blends was similar to the control. In contrast, on the laser‐treated surfaces fibroblast cells showed different proliferation. On the other hand, fewer platelets adhered to the laser‐treated surface than adhered to the blend and the unmodified PDMS surfaces. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2522–2529, 2003     

CSBD Healing in Rats after Application of Bovine Xenogeneic Biomaterial Enriched with Magnesium Alloy

Xenogeneic biomaterials Cerbone^® and OsteoBiol^® are widely used in oral implantology. In dental practice, xenogeneic biomaterial is usually combined with autologous bone to provide bone volume stability needed for long-term dental implants. Magnesium alloy implants dissolve and form mineral corrosion layer that is directly in contact with bone tissue, allowing deposition of the newly formed bone. CSBD heals by intramembranous ossification and therefore is a convenient model for analyses of ostoconductive and osteoinductive properties of different type of biomaterials. Magnesium alloy-enriched biomaterials have not yet been applied in oral implantology. Therefore, the aim of the current study was to investigate biological properties of potentially new bovine xenogeneic biomaterial enriched with magnesium alloy in a 5 mm CSBD model. Osteoconductive properties of Cerabone^®, Cerabone^® + Al. bone, and OsteoBiol^® were also analyzed. Dynamics of bone healing was followed up on the days 3, 7, 15, 21, and 30. Calvary bone samples were analyzed by micro-CT, and values of the bone morphometric parameters were assessed. Bone samples were further processed for histological and immunohistochemical analyses. Histological observation revealed CSBD closure at day 30 of the given xenogeneic biomaterial groups, with the exception of the control group. TNF-α showed high intensity of expression at the sites of MSC clusters that underwent ossification. Osx was expressed in pre-osteoblasts, which were differentiated into mature osteoblasts and osteocytes. Results of the micro-CT analyses showed linear increase in bone volume of all xenogeneic biomaterial groups and also in the control. The highest average values of bone volume were found for the Cerabone^® + Mg group. In addition, less residual biomaterial was estimated in the Cerabone^® + Mg group than in the Cerabone^® group, indicating its better biodegradation during CSBD healing. Overall, the magnesium alloy xenogeneic biomaterial demonstrated key properties of osteoinduction and biodegradidibility during CSBD healing, which is the reason why it should be recommended for application in clinical practice of oral implantology.     

Dietary conjugated linoleic acid did not alter immune status in young healthy women

The purpose of this study was to examine whether conjugated linoleic acid (CLA) supplementation in human diets would enhance indices of immune status as reported by others for animal models. Seventeen women, 20–41 yr, participated in a 93-d study conducted in two cohorts of 9 and 8 women at the Metabolic Research Unit of Western Human Nutrition Research Center. Seven subjects were fed the basal diet (19, 30 and 51% energy from protein, fat, and carbohydrate, respectively) throughout the study. The remaining 10 subjects were fed the basal diet for the first 30 d, followed by 3.9 g CLA (Tonalin)/d for the next 63 d. CLA made up 65% of the fatty acids in the Tonalin capsules, with the following isomeric composition: t10, c12, 22.6%; c11, t13, 23.6%; c9, t11, 17.6%; t8, c10, 16.6%; and other isomers 19.6%. Most indices of immune response were tested at weekly intervals, three times at the end of each period (stabilization/intervention); delayed-type hypersensitivity (DTH) to a panel of six recall antigens was tested on study day 30 and 90; all subjects were immunized on study day 65 with an influenza vaccine, and antibody titers were examined in the sera collected on day 65 and 92. None of the indices of immune status tested (number of circulating white blood cells, granulocytes, monocytes, lymphocytes, and their subsets, lymphocytes proliferation in response to phytohemagglutinin, and influenza vaccine, serum influenza antibody titers, and DTH response) were altered during the study in either dietary group. Thus, in contrast to the reports with animal models, CLA feeding to young healthy women did not alter any of the indices of immune status tested. These data suggest that short-term CLA supplementation in healthy volunteers is safe, but it does not have any added benefit to their immune status. Parts of data included here were published as an abstract for the Experimental Biology 2000, meeting.     

The physiological relevance of wet versus dry differential scanning calorimetry for biomaterial evaluation: a technical note

Collagen and its denatured form, gelatin, have been extensively used as scaffolds for tissue engineering and tissue repair applications. Denaturation temperature, commonly measured using differential scanning calorimetry (DSC), for biomaterial applications is a significant physical property that will determine the stability of a potential implant at body temperature. In order to imitate a clinical setting, DSC should be run under fully hydrated conditions. We show here that for hydrophobic polymers such as poly(ε‐caprolactone) and chitosan there is no significant difference between dry and wet DSC operation (p > 0.05). In contrast, for hydrophilic polymers such as collagen, gelatin, poly(ethylene glycol) (40 kDa) and poly(ethylene oxide) (900 kDa) significant differences occur between measurements in the dry and the wet state (p < 0.0011). Moreover, we demonstrate that only when wet DSC is carried out are we able to separate the unique crystalline structure of collagen from its randomly coiled heat‐denatured by‐product gelatin (p < 0.0005). We therefore recommend running DSC under fully hydrated conditions when the function and properties of a biomaterial are under investigation. Copyright © 2010 Society of Chemical Industry     

The effect of highly purified eicosapentaenoic and docosahexaenoic acids on monocyte phagocytosis in man

The n-3 fatty acids (FA) from marine sources are known to exert antiinflammatory effects on monocyte function. There is still controversy whether n-3 FA may increase the susceptibility to infections. The present study was designed to assess the effect of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHa) on monocyte phagocytosis and respiratory burst activity. Fifty-eight healthy men were randomized to take a daily supplement of 3.8 g highly purified EPA (n=20), 3.6 g DHA (n=19), or corn oil (n=19) for 7 wk. Mononuclear leukocytes were collected, isolated, and cryopreserved prior to and after dietary supplementation. Paired samples were analyzed in the presence of autologous serum in a crossover design. Monocyte phagocytosis and respiratory burst activity were measured by flow cytometry after ingestion of Escherichia coli. Monocytes retained their phagocytic ability and respiratory burst activity after supplementation. No reduction in internalization of bacteria was registered. Dietary n-3 FA and particularly EPA improved bacterial adherence to the monocyte surface. In the crossover experiments, there was an adverse effect of serum enriched with n-3 FA on bacterial adherence. We conclude that monocytes retain their phagocytic potential after supplementation with purified EPA and DHA.     

Consideration of the methods for evaluating the Cr(VI)-removing capacity of biomaterial

Over the last few decades, many researchers have tested various biomaterials for the removal of toxic Cr(VI) from aquatic systems. It is now widely accepted that the mechanism of Cr(VI) biosorption is not ‘anionic adsorption’ but ‘adsorption-coupled reduction’. Unfortunately, however, many researchers have still used common equilibrium isotherm models, such as Langmuir and Freundlich ones, based on ‘anionic adsorption’ mechanism in order to evaluate the Cr(VI)-removing capacity of biomaterial tested. In this study, a fermentation waste of Corynebacterium glutamicum, capable of removing Cr(VI) efficiently, was used as a model biomaterial to show why equilibrium isotherm models cannot be used to evaluate the Cr(VI)-removing capacity of biomaterial. Meanwhile, some alternative methods considering the mechanism of Cr(VI) biosorption were suggested; the maximum Cr(VI)-removing capacity of the biomaterial could be evaluated by a Cr(VI)-biosorption experiment under biomaterial-limited condition as well as by a simplified kinetic model based on the reduction mechanism of Cr(VI).     

Clionapyrrolidine A—A Metabolite from the Encrusting and Excavating Sponge Cliona tenuis that Kills Coral Tissue upon Contact

The Caribbean encrusting and excavating sponge Cliona tenuis successfully competes for space with reef corals by undermining, killing, and displacing live coral tissue at rates of up to 20 cm per year. The crude extract from this sponge, along with the more polar partitions, kills coral tissue and lowers the photosynthetic potential of coral zooxanthellae. We used a bioassay-guided fractionation of the extract to identify the compound(s) responsible. The crude extract, the aqueous partition, and compound 1, herein named clionapyrrolidine A [(−)-(5S)-2-imino-1-methylpyrrolidine-5-carboxylic acid], when incorporated into gels at close to natural volumetric concentrations, killed coral tissue when brought into forced contact with live coral for periods of 1–4 days. This is the first report of a pure chemical produced by a sponge that kills coral tissue upon direct contact. The results are consistent with the localized coral death that occurs when C. tenuis-colonized coral fragments are thrown forcibly against live coral during storms. However, healed C. tenuis fragments placed directly onto live coral were killed readily by coral defenses, and fragments placed in close proximity to coral did not have any effect on the adjacent coral tissue. Solutions of clionapyrrolidine A in sea water were only slightly toxic against live coral. Hence, the coral death naturally brought about by C. tenuis when undermining live coral does not occur through external release of allelochemicals; below-polyp mechanisms must be explored further. N-acetylhomoagmatine (2), originally isolated from Cliona celata from the Northeastern Atlantic, was also assayed for comparison purposes because of its structural similarity to siphonodictidine, a toxic compound produced by a coral excavating sponge of the genus Aka. The lack of activity of N-acetylhomoagmatine at close to natural concentrations seems to indicate that the guanidine moiety, which is also present in siphonodictidine, is not a sufficiently strong structural motif for activity against corals.     

The Role of Biodegradable Poly-(L-lactide)-Based Polymers in Blood Cell Activation and Platelet-Monocyte Interaction

The main purpose of new stent technologies is to overcome unfavorable material-related incompatibilities by producing bio- and hemo-compatible polymers with anti-inflammatory and anti-thrombogenic properties. In this context, wettability is an important surface property, which has a major impact on the biological response of blood cells. However, the influence of local hemodynamic changes also influences blood cell activation. Therefore, we investigated biodegradable polymers with different wettability to identify possible aspects for a better prediction of blood compatibility. We applied shear rates of 100 s⁻¹ and 1500 s⁻¹ and assessed platelet and monocyte activation as well as the formation of CD62P+ monocyte-bound platelets via flow cytometry. Aggregation of circulating platelets induced by collagen was assessed by light transmission aggregometry. Via live cell imaging, leukocytes were tracked on biomaterial surfaces to assess their average velocity. Monocyte adhesion on biomaterials was determined by fluorescence microscopy. In response to low shear rates of 100 s⁻¹, activation of circulating platelets and monocytes as well as the formation of CD62P+ monocyte-bound platelets corresponded to the wettability of the underlying material with the most favorable conditions on more hydrophilic surfaces. Under high shear rates, however, blood compatibility cannot only be predicted by the concept of wettability. We assume that the mechanisms of blood cell-polymer interactions do not allow for a rule-of-thumb prediction of the blood compatibility of a material, which makes extensive in vitro testing mandatory.     

Review of zirconia-based bioceramic: Surface modification and cellular response

Zirconia is gaining interest as a ceramic biomaterial for implant applications due to its biocompatibility and desirable mechanical properties. At present, zirconia-based ceramic is often seen in the applications of hip replacement and dental implants. This paper briefly reviews different surface modification techniques that have been applied to zirconia such as polishing, sandblasting, etching, biofunctionalization, coating, laser treatment, and ultraviolet light treatment. The cellular response of osteoblast-like cell, osteoblast cell, fibroblast, and epithelial cell to the modified surface is discussed in terms of their adhesion, proliferation, and metabolic activity. The potential of surface modification to make zirconia a successful implant material in the future is highly dependent on the establishment of successful in vitro and in vivo studies. Hence, further effort should be made in order to deepen the understanding of tissue response to the implant and the tissue regeneration process. The review concludes with future prospect of research and further challenges in developing better zirconia bioceramics.