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OBJECTIVES: This study aimed to evaluate the effects of incorporating the 0-20 wt% tetrapod-shaped zinc oxide (tZnO) whiskers on the mechanical, antibacterial, and cytotoxic properties exhibited by experimental dual-cure resin composites. METHODS: Commercially obtained tZnO whiskers underwent surface modification using 3-methacryloxypropyltrimethoxysilane (γ-MPS). Subsequently, four groups of resin composites containing 0, 5, 10, and 20 wt% silanized tZnO along with barium borosilicate glass (BaBSG) fillers were fabricated while maintaining total filler loading at 60 wt%. Mechanical properties were examined utilizing specimens produced adhering to ISO 4049:2019 guidelines where applicable. Depth of cure was quantified immediately, while three-point flexural strength, flexural modulus, fracture toughness, Vickers hardness, compressive strength, and diametral tensile strength were assessed after 24 h of storage in 37 °C distilled water. Planktonic bacteria of Streptococcus mutans (S. mutans) were cultured and tested for antibacterial activity using disk diffusion and microbial anti-adhesion assays. Cytotoxicity was examined by preparing extracts from specimens in a cell culture medium and exposing stem cells from human exfoliated deciduous teeth (SHED) to serial dilutions of these extracts, then assessing cell viability and survival using CCK-8 assay and live/dead staining. RESULTS: Elevating tZnO loading yielded significant reductions in depth of cure, compressive (from 296.4 to 254.6 MPa), and diametral tensile strength (from 42.7 to 31.0 MPa), while flexural strength (91.3-94.1 MPa), flexural modulus (6.4-6.6 GPa), fracture toughness (0.96-1.04 MPa·m0.5), and Vickers hardness (36.5-37.4 kgf·mm-2) remained the same. Composites integrating tZnO displayed markedly enhanced antibacterial activity against S. mutans, based on anti-adhesion tests and live/dead staining. No cytotoxicity was observed for SHED treated with extracts from resin composites possessing up to 20 wt% tZnO whiskers. SIGNIFICANCE: This study demonstrates that incorporating up to 20 wt% silanized tZnO in place of traditional barium glass particles appreciably enhances dual-cure resin composite antibacterial function against S. mutans without compromising mechanical properties.
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Electrical conductivity is a pivotal biophysical factor for neural interfaces, though optimal values remain controversial due to challenges isolating this cue. To address this issue, conductive substrates made of carbon nanotubes and graphene oxide nanoribbons, exhibiting a spectrum of conductivities from 0.02 to 3.2 S m-1, while controlling other surface properties is designed. The focus is to ascertain whether varying conductivity in isolation has any discernable impact on neural lineage specification. Remarkably, neural-tissue-like low conductivity (0.02-0.1 S m-1) prompted neural stem/progenitor cells to exhibit a greater propensity toward neuronal lineage specification (neurons and oligodendrocytes, not astrocytes) compared to high supraphysiological conductivity (3.2 S m-1). High conductivity instigated the apoptotic process, characterized by increased apoptotic fraction and decreased neurogenic morphological features, primarily due to calcium overload. Conversely, cells exposed to physiological conductivity displayed epigenetic changes, specifically increased chromatin openness with H3acetylation (H3ac) and neurogenic-transcription-factor activation, along with a more balanced intracellular calcium response. The pharmacological inhibition of H3ac further supported the idea that such epigenetic changes might play a key role in driving neuronal specification in response to neural-tissue-like, not supraphysiological, conductive cues. These findings underscore the necessity of optimal conductivity when designing neural interfaces and scaffolds to stimulate neuronal differentiation and facilitate the repair process.
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In recent years, there has been a surge in demand for and research focus on cell therapy, driven by the tissue-regenerative and disease-treating potentials of stem cells. Among the candidates, dental pulp stem cells (DPSCs) or human exfoliated deciduous teeth (SHED) have garnered significant attention due to their easy accessibility (non-invasive), multi-lineage differentiation capability (especially neurogenesis), and low immunogenicity. Utilizing these stem cells for clinical purposes requires careful culture techniques such as excluding animal-derived supplements. Human platelet lysate (hPL) has emerged as a safer alternative to fetal bovine serum (FBS) for cell culture. In our study, we assessed the impact of hPL as a growth factor supplement for culture medium, also conducting a characterization of SHED cultured in hPL-supplemented medium (hPL-SHED). The results showed that hPL has effects in enhancing cell proliferation and migration and increasing cell survivability in oxidative stress conditions induced by H2O2. The morphology of hPL-SHED exhibited reduced size and elongation, with a differentiation capacity comparable to or even exceeding that of SHED cultured in a medium supplemented with fetal bovine serum (FBS-SHED). Moreover, no evidence of chromosome abnormalities or tumor formation was detected. In conclusion, hPL-SHED emerges as a promising candidate for cell therapy, exhibiting considerable potential for clinical investigation.
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Plaquetas , Diferenciación Celular , Proliferación Celular , Células Madre , Diente Primario , Humanos , Diente Primario/citología , Células Madre/citología , Células Madre/metabolismo , Plaquetas/metabolismo , Bovinos , Diferenciación Celular/efectos de los fármacos , Animales , Proliferación Celular/efectos de los fármacos , Pulpa Dental/citología , Movimiento Celular/efectos de los fármacos , Medios de Cultivo/farmacología , Células Cultivadas , Extractos Celulares/farmacología , Peróxido de Hidrógeno/farmacología , Estrés Oxidativo/efectos de los fármacos , Supervivencia Celular/efectos de los fármacosRESUMEN
Periodontal ligament (PDL) cells play a crucial role in maintaining periodontal integrity and function by providing cell sources for ligament regeneration. While biophysical stimulation is known to regulate cell behaviors and functions, its impact on epigenetics of PDL cells has not yet been elucidated. Here, we aimed to investigate the cytoskeletal changes, epigenetic modifications, and lineage commitment of PDL cells following the application of stretch stimuli to PDL. PDL cells were subjected to stretching (0.1 Hz, 10 %). Subsequently, changes in focal adhesion, tubulin, and histone modification were observed. The survival ability in inflammatory conditions was also evaluated. Furthermore, using a rat hypo-occlusion model, we verified whether these phenomena are observed in vivo. Stretched PDL cells showed maximal histone 3 acetylation (H3Ace) at 2 h, aligning perpendicularly to the stretch direction. RNA sequencing revealed stretching altered gene sets related to mechanotransduction, histone modification, reactive oxygen species (ROS) metabolism, and differentiation. We further found that anchorage, cell elongation, and actin/microtubule acetylation were highly upregulated with mechanosensitive chromatin remodelers such as H3Ace and histone H3 trimethyl lysine 9 (H3K9me3) adopting euchromatin status. Inhibitor studies showed mechanotransduction-mediated chromatin modification alters PDL cells behaviors. Stretched PDL cells displayed enhanced survival against bacterial toxin (C12-HSL) or ROS (H2O2) attack. Furthermore, cyclic stretch priming enhanced the osteoclast and osteoblast differentiation potential of PDL cells, as evidenced by upregulation of lineage-specific genes. In vivo, PDL cells from normally loaded teeth displayed an elongated morphology and higher levels of H3Ace compared to PDL cells with hypo-occlusion, where mechanical stimulus is removed. Overall, these data strongly link external physical forces to subsequent mechanotransduction and epigenetic changes, impacting gene expression and multiple cellular behaviors, providing important implications in cell biology and tissue regeneration.
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Biomimetic stress-relaxing hydrogels with reversible crosslinks attract significant attention for stem cell tissue regeneration compared with elastic hydrogels. However, stress-relaxing hyaluronic acid (HA)-based hydrogels fabricated using conventional technologies lack stability, biocompatibility, and mechanical tunability. Here, it is aimed to address these challenges by incorporating calcium or phosphate components into the HA backbone, which allows reversible crosslinking of HA with alginate to form interpenetrating networks, offering stability and mechanical tunability for mimicking cartilage. Diverse stress-relaxing hydrogels (τ1/2; SR50, 60-2000 s) are successfully prepared at ≈3 kPa stiffness with self-healing and shear-thinning abilities, favoring hydrogel injection. In vitro cell experiments with RNA sequencing analysis demonstrate that hydrogels tune chondrogenesis in a biphasic manner (hyaline or calcified) depending on the stress-relaxation properties and phosphate components. In vivo studies confirm the potential for biphasic chondrogenesis. These results indicate that the proposed stress-relaxing HA-based hydrogel with biphasic chondrogenesis (hyaline or calcified) is a promising material for cartilage regeneration.
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Cartílago , Condrogénesis , Ácido Hialurónico , Hidrogeles , Regeneración , Ácido Hialurónico/química , Ácido Hialurónico/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Condrogénesis/efectos de los fármacos , Animales , Regeneración/efectos de los fármacos , Cartílago/efectos de los fármacos , Cartílago/fisiología , Humanos , Estrés Mecánico , Ingeniería de Tejidos/métodos , RatonesRESUMEN
The surface topological features of bioimplants are among the key indicators for bone tissue replacement because they directly affect cell morphology, adhesion, proliferation, and differentiation. In this study, we investigated the physical, electrochemical, and biological responses of sandblasted titanium (SB-Ti) surfaces with pore geometries fabricated using a plasma electrolytic oxidation (PEO) process. The PEO treatment was conducted at an applied voltage of 280 V in a solution bath consisting of 0.15 mol L-1 calcium acetate monohydrate and 0.02 mol L-1 calcium glycerophosphate for 3 min. The surface chemistry, wettability, mechanical properties and corrosion behavior of PEO-treated sandblasted Ti implants using hydroxyapatite particles (PEO-SB-Ti) were improved with the distribution of calcium phosphorous porous oxide layers, and showed a homogeneous and hierarchically porous surface with clusters of nanopores in a bath containing calcium acetate monohydrate and calcium glycerophosphate. To demonstrate the efficacy of PEO-SB-Ti, we investigated whether the implant affects biological responses. The proposed PEO-SB-Ti were evaluated with the aim of obtaining a multifunctional bone replacement model that could efficiently induce osteogenic differentiation as well as antibacterial activities. These physical and biological responses suggest that the PEO-SB-Ti may have a great potential for use an artificial bone replacement compared to that of the controls.
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Durapatita , Oxidación-Reducción , Propiedades de Superficie , Titanio , Titanio/química , Porosidad , Durapatita/química , Tornillos Óseos , Animales , Humectabilidad , Ensayo de Materiales , Osteogénesis/efectos de los fármacos , Electrólisis , Gases em Plasma/química , Diferenciación Celular/efectos de los fármacos , Corrosión , Materiales Biocompatibles/química , Osteoblastos/citología , RatonesRESUMEN
Poly(methyl methacrylate) (PMMA) is commonly used for dental dentures, but it has the drawback of promoting oral health risks due to oral bacterial adhesion. Recently, various nanoparticles have been incorporated into PMMA to tackle these issues. This study aims to investigate the mechanophysical and antimicrobial adhesive properties of a denture resin by incorporating of nanoclay into PMMA. Specimens were prepared by adding 0, 1, 2, and 4 wt % surface-modified nanoclay (Sigma) to self-polymerizing PMMA denture resin. These specimens were then evaluated using FTIR, TGA/DTG, and FE-SEM with EDS. Various mechanical and surface physical properties, including nanoindentation, were measured and compared with those of pure PMMA. Antiadhesion experiments were conducted by applying a Candida albicans (ATCC 11006) suspension to the surface of the specimens. The antiadhesion activity of C. albicans was confirmed through a yeast-wall component (mannan) and mRNA-seq analysis. The bulk mechanical properties of nanoclay-PMMA composites were decreased compared to those of pure PMMA, while the flexural strength and modulus met the ISO 20795-1 requirement. However, there were no significant differences in the nanoindentation hardness and elastic modulus. The surface energy revealed a significant decrease at 4 wt % nanoclay-PMMA. The antiadhesion effect of Candida albicans was evident along with nanoclay content in the nanocomposites and confirmed by the reduced attachment of mannan on nanoclay-PMMA composites. mRNA-seq analysis supported overall transcriptome changes in altering attachment and metabolism behaviors on the surface. The nanoclay-PMMA materials showed a lower surface energy as the content increased, leading to an antiadhesion effect against Candida albicans. These findings indicate that incorporating nanoclay into PMMA surfaces could be a valuable strategy for preventing the fungal biofilm formation of denture base materials.
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Adhesivos , Polimetil Metacrilato , Mananos , Ensayo de Materiales , Dentaduras , ARN MensajeroRESUMEN
OBJECTIVE: This study aimed to compare the four-point flexural strength of CAM-milled and sintered (as-sintered, AS) specimens with those of high-polished (HP) specimens using chairside polishing systems to simulate clinical surface conditions. METHODS: Seven full-contour zirconia CAM/CAM blanks with various yttria contents (3, 4, 5 mol%) including three high-translucent groups (5Y) were selected to prepare flexural specimens. The bend bar specimens (2.0 × 4.0 × 25.0 mm3) were fabricated by using STL file and dental CAM machine with the respective zirconia blanks (98 mm Ï and 10-14 mm in height). Twelve bar specimens were machined from one zirconia puck and a total of 24 specimens were prepared from each group. The pre-sintered bar specimens were sintered by using a dental zirconia furnace at 1530-1550 °C for 2 h according to the instructions. All sintered specimens were divided into two groups: as-sintered (AS) group and high-polished (HP) groups (n = 12). HP groups were subjected to polishing one surface of specimens using a three-step polishing system and finally finished with diamond polishing. After cleaning and drying, the flexural strength of all specimens was determined by a fully articulating four-point flexure fixture consisting of a 1/4-point test configuration with an inner/outer span of 10/20 mm. Statistical differences between AS and HP groups were conducted with Weibull analysis. The fractured surfaces of zirconia specimens were observed using a field emission SEM and EDS to detect failure origins. RESULTS: The mean AS flexural strength values were significantly lower than those of HP counterparts. However, Weibull moduli expressing the reliability of HP groups were generally decreased although not significantly in comparison to their AS. The fracture of the AS specimens mostly originated from extrinsic CAM-milling defects, while the HP specimens were fractured from intrinsic subsurface or volume defects including pores, large grain clusters, inclusions, and corner-located critical flaws. Two high-translucent (5Y) zirconia groups were not affected in their strength and reliability after polishing, whereas one 5Y zirconia significantly increased its strength but significantly lowered its reliability. SIGNIFICANCE: The extrinsic and intrinsic strength-limiting defects should be considered in evaluating the flexural strength and reliability of dental CAD/CAM zirconia ceramics for full-contour restorations. For the materials tested in this study, more optimized processing of blanks and milling protocols of pre-sintered zirconia blanks should be developed including post-sintering surface finishing to reduce the flaw population regulating strength and reliability which will affect the survivability of dental zirconia prostheses.
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Cerámica , Materiales Dentales , Ensayo de Materiales , Reproducibilidad de los Resultados , Circonio , Propiedades de Superficie , ItrioRESUMEN
OBJECTIVES: This study assessed the changes in color stability and biocompatibility of computer-aided design and computer-aided manufacturing (CAD-CAM) glass-ceramics after ultraviolet weathering (UW) aging. METHODS: A total of 300 plate-shaped specimens (12.0 × 14.0 × 1.5 mm3) were prepared using a leucite-reinforced glass-ceramic (IPS Empress CAD; E), a lithium disilicate (IPS e.max CAD; M), and two zirconia-reinforced lithium silicate (Celtra Duo; C, Vita Suprinity; V) glass-ceramics. Specimens were divided into three groups (n = 25, each), subjected to water storage at 37 °C for 24 h (control group), or UW aging at 150 kJ/m2 (first-aged group) or 300 kJ/m2 (second-aged group). The color stability, mechanical and surface properties, and biocompatibility of the CAD-CAM glass-ceramics were investigated experimentally, followed by statistical analysis. RESULTS: The brightness and redness or greenness were reduced in all groups after aging. After the first aging, V exhibited the largest color change and E exhibited the smallest color change. After the second aging, E exhibited the highest nanoindentation hardness and Young's modulus. The surface roughness was the highest for V after the first aging. Furthermore, the hydrophilicity of the materials increased after aging process. The cell proliferation/viability of human gingival fibroblasts was the highest in E before and after aging. Almost all cells survived for all groups based on a live/dead assay. CONCLUSIONS: Leucite-reinforced glass-ceramic exhibit the highest color stability and biocompatibility after aging. The color stability and biocompatibility of CAD-CAM glass-ceramics depend on the aging process and material type. CLINICAL SIGNIFICANCE: Various CAD-CAM glass-ceramics exhibit adequate color stability after UW aging. The leucite-reinforced glass-ceramics exhibit the highest color stability, cell proliferation, and viability after aging. The color stability, mechanical and surface properties, and biocompatibility of the glass-ceramics depend on the aging process and material type.
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Cerámica , Porcelana Dental , Humanos , Anciano , Silicatos de Aluminio , Propiedades de Superficie , Diseño Asistido por Computadora , Ensayo de MaterialesRESUMEN
The purpose of this study is to evaluate the changes in physical properties and biocompatibilities caused by thermocycling of CAD/CAM restorative materials (lithium disilicate, zirconia reinforced lithium silicate, polymer-infiltrated ceramic network, resin nanoceramic, highly translucent zirconia). A total of 225 specimens were prepared (12.0 × 10.0 × 1.5 mm) and divided into three groups subjected to water storage at 37 °C for 24 h (control group), 10,000 cycles in distilled water at 5-55 °C (first aged group), and 22,000 cycles in distilled water at 5-55 °C (second aged group) [(n= 15, each]). The nanoindentation hardness and Young's modulus (nanoindenter), surface roughness (atomic force microscopy (AFM)), surface texture (scanning electron microscopy (FE-SEM)), elemental concentration (energy dispersive spectroscopy (EDS)) and contact angle were evaluated. The morphology, proliferation and adhesion of cultured human gingival fibroblasts (HGFs) were analyzed. The data were analyzed using one-way ANOVA and Tukey's test (p < 0.05). The results showed that the nanoindentation hardness and Young's modulus were decreased after thermocycling aging. Cell viability and proliferation of the material decreased with aging except for the highly translucent zirconia. Zirconia-reinforced lithium silicate exhibited significantly lower cell viability compared to other materials. The surface roughnesses of all groups increased with aging. Cell viability and Cell adhesion were influenced by various factors, including the surface chemical composition, hydrophilicity, surface roughness, and topography.
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Calcium silicate-based cement (CSC) is a pharmaceutical agent that is widely used in dentistry. This bioactive material is used for vital pulp treatment due to its excellent biocompatibility, sealing ability, and antibacterial activity. Its drawbacks include a long setting time and poor maneuverability. Hence, the clinical properties of CSC have recently been improved to decrease its setting time. Despite the widespread clinical usage of CSC, there is no research comparing recently developed CSCs. Therefore, the purpose of this study is to compare the physicochemical, biological, and antibacterial properties of four commercial CSCs: two powder-liquid mix types (RetroMTA® [RETM]; Endocem® MTA Zr [ECZR]) and two premixed types (Well-Root™ PT [WRPT]; Endocem® MTA premixed [ECPR]). Each sample was prepared using circular Teflon molds, and tests were conducted after 24 h of setting. The premixed CSCs exhibited a more uniform and less rough surface, higher flowability, and lower film thickness than the powder-liquid mix CSCs. In the pH test, all CSCs showed values between 11.5 and 12.5. In the biological test, cells exposed to ECZR at a concentration of 25% showed greater cell viability, but none of the samples showed a significant difference at low concentration (p > 0.05). Alkaline phosphatase staining revealed that cells exposed to ECZR underwent more odontoblast differentiation than the cells exposed to the other materials; however, no significant difference was observed at a concentration of 12.5% (p > 0.05). In the antibacterial test, the premixed CSCs showed better results than the powder-liquid mix CSCs, and ECPR yielded the best results, followed by WRPT. In conclusion, the premixed CSCs showed improved physical properties, and of the premixed types, ECPR exhibited the highest antibacterial properties. For biological properties, none of these materials showed significant differences at 12.5% dilution. Therefore, ECPR may be a promising material with high antibacterial activity among the four CSCs, but further investigation is needed for clinical situations.
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This study aimed to investigate the impact of different viscosities of silicone oil on the physicochemical, pre-clinical usability, and biological properties of a sodium iodide paste. Six different paste groups were created by mixing therapeutic molecules, sodium iodide (D30) and iodoform (I30), with calcium hydroxide and one of the three different viscosities of silicone oil (high (H), medium (M), and low (L)). The study evaluated the performance of these groups, including I30H, I30M, I30L, D30H, D30M, and D30L, using multiple parameters such as flow, film thickness, pH, viscosity, and injectability, with statistical analysis (p < 0.05). Remarkably, the D30L group demonstrated superior outcomes compared to the conventional iodoform counterpart, including a significant reduction in osteoclast formation, as examined through TRAP, c-FOS, NFATc1, and Cathepsin K (p < 0.05). Additionally, mRNA sequencing showed that the I30L group exhibited increased expression of inflammatory genes with upregulated cytokines compared to the D30L group. These findings suggest that the optimized viscosity of the sodium iodide paste (D30L) may lead to clinically favorable outcomes, such as slower root resorption, when used in primary teeth. Overall, the results of this study suggest that the D30L group shows the most satisfactory outcomes, which may be a promising root-filling material that could replace conventional iodoform-based pastes.
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OBJECTIVES: To investigate the influence of thermal cycling and mechanical loading (TCML) aging on fracture resistance and wear behavior of various chairside computer-aided-designed/computer-assisted-manufactured (CAD/CAM) premolar crowns cemented on standardized tooth abutments. METHODS: Eighty chairside CAD/CAM crowns were prepared using lithium disilicate (IPS e.max CAD; EM), zirconia-infiltrated lithium silicate (Celtra Duo; CD), polymer-infiltrated ceramic network (Vita Enamic; VE), and resin nanoceramics (Cerasmart; CS) (n = 20). The specimens were divided into two groups (n = 10). In one group, they were subjected to TCML: thermocycling (6000 cycles in distilled water at 5-55 °C) and mechanical loading (50 N for 1.2 × 106 cycles), while in control group they were stored in distilled water (37 °C for 24 h). The fracture load, height loss, and volume wear of the crowns were measured after TCML. Fractography was performed on fractured specimens. Data were analyzed using analysis of variance and multiple comparison tests (α=0.05). RESULTS: The mean fracture loads of EM and CD were significantly higher than those of EC and CS (p<0.05). There was no significant change in the fracture load of any CAD/CAM crowns after TCML (p>0.05). CS exhibited a significantly higher volume wear than the other materials investigated. The wear tracts of all TCML crowns acted as failure origins during the fracture test. CONCLUSIONS: The fracture resistance of glass-ceramic CAD/CAM crowns was significantly higher than that of resin composite crowns. A 5-year TCML aging did not affect the fracture resistance of CAD/CAM crowns investigated. However, TCML treatment produces a larger wear track in CS than in other materials. CLINICAL SIGNIFICANCE: Appropriate chairside CAD/CAM restorative material should be selected for successful clinical practice after considering the fracture and wear resistance of the crowns.
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Cerámica , Fracaso de la Restauración Dental , Porcelana Dental , Coronas , Materiales Dentales , Resinas Compuestas , Diseño Asistido por Computadora , Agua , Ensayo de Materiales , Análisis del Estrés DentalRESUMEN
Neural stem cells (NSC) have tremendous potential for therapeutic regeneration of diseased or traumatized neural tissues, including injured spinal cord. However, transplanted NSC suffer from low cell survival and uncontrolled differentiation, limiting in vivo efficacy. Here, this issue is tackled by delivery through silk-collagen protein hydrogels that are stiffness-matched, stress-relaxing, and shear-thinning. The mechanically-tuned hydrogels protect NSC reprogrammed from fibroblasts (iNSC) initially from injection shear-stress, and enhance long-term survival over 12 weeks. Hydrogel-iNSC treatment alleviates neural inflammation, with reduced inflammatory cells and lesions than NSC-only. The iNSC migrate from the hydrogel into surrounding tissues, secrete up-regulated neurotrophic factors, and differentiate into neural cell subtypes, forming synapses. More serotonergic axons are observed in the lesion cavity, and locomotor functions are improved in hydrogel-iNSC than in iNSC-only. This study highlights the ability of mechanically-tuned protein hydrogels to protect iNSC from the injection stress and severe inflammatory environment, allowing them to differentiate and function to recover the injured spinal cord.
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Células-Madre Neurales , Traumatismos de la Médula Espinal , Ratas , Animales , Traumatismos de la Médula Espinal/terapia , Traumatismos de la Médula Espinal/patología , Hidrogeles/farmacología , Hidrogeles/metabolismo , Seda/metabolismo , Médula Espinal/patología , Colágeno/metabolismo , Recuperación de la FunciónRESUMEN
Rigidity (or stiffness) of materials and extracellular matrix has proven to be one of the most significant extracellular physicochemical cues that can control diverse cell behaviors, such as contractility, motility, and spreading, and the resultant pathophysiological phenomena. Many 2D materials engineered with tunable rigidity have enabled researchers to elucidate the roles of matrix biophysical cues in diverse cellular events, including migration, lineage specification, and mechanical memory. Moreover, the recent findings accumulated under 3D environments with viscoelastic and remodeling properties pointed to the importance of dynamically changing rigidity in cell fate control, tissue repair, and disease progression. Thus, here we aim to highlight the works related with material/matrix-rigidity-mediated cell and tissue behaviors, with a brief outlook into the studies on the effects of material/matrix rigidity on cell behaviors in 2D systems, further discussion of the events and considerations in tissue-mimicking 3D conditions, and then examination of the in vivo findings that concern material/matrix rigidity. The current discussion will help understand the material/matrix-rigidity-mediated biological phenomena and further leverage the concepts to find therapeutic targets and to design implantable materials for the treatment of damaged and diseased tissues.
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Regenerative endodontic treatment based on tissue engineering has recently gained interest in contemporary restorative dentistry. However, low survival rates and poor potential differentiation of stem cells could undermine the success rate of pulp regenerative therapy. Human gingival fibroblast-conditioned medium (hGF-CM) has been considered a potential therapy for tissue regeneration due to its stability in maintaining multiple factors essential for tissue regeneration compared to live cell transplantation. This study aimed to investigate the potency of hGF-CM on stem cells from human dental pulp (DPSC) in pulp regeneration. A series of experiments confirmed that hGF-CM contributes to a significant increase in proliferation, migration capability, and cell viability of DPSC after H2O2 exposure. Moreover, it has been proved to facilitate the odontogenic differentiation of DPSC via qRT-PCR, ALP (alkaline phosphatase), and ARS (Alizarin Red S) staining. It has been discovered that such highly upregulated odontogenesis is related to certain types of ECM proteins (collagen and laminin) from hGF-CM via proteomics. In addition, it is found that the ERK pathway is a key mechanism via inhibition assay based on RNA-seq result. These findings demonstrate that hGF-CM could be beneficial biomolecules for pulp regeneration.
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Medios de Cultivo Condicionados , Pulpa Dental , Peróxido de Hidrógeno , Ingeniería de Tejidos , Humanos , Fosfatasa Alcalina/metabolismo , Medios de Cultivo Condicionados/química , Medios de Cultivo Condicionados/farmacología , Pulpa Dental/efectos de los fármacos , Pulpa Dental/metabolismo , Fibroblastos/metabolismo , Regeneración , Encía/citología , Encía/metabolismo , Ingeniería de Tejidos/métodosRESUMEN
Recently, bioactive glass nanoparticles (BGns) have been acknowledged for their ability to promote interactions with the periapical tissue and enhance tissue regeneration by releasing therapeutic ions. However, there have been no studies on calcium silicate sealers with bioactive glass nanoparticle (BGn) additives. In the present study, a premixed calcium silicate root canal sealer reinforced with BGn (pre-mixed-RCS@BGn) was developed and its physicochemical features and biological effects were analyzed. Three specimens were in the trial: 0%, 0.5%, and 1% bioactive glass nanoparticles (BGns) were gradually added to the premixed type of calcium silicate-based sealer (pre-mixed-RCS). To elucidate the surface properties, scanning electron microscopy, X-ray diffraction, and energy-dispersive spectroscopy were used and flowability, setting time, solubility, and radiopacity were analyzed to evaluate the physical properties. Chemical properties were investigated by water contact angle, pH change, and ion release measurements. The antibacterial effects of the bioactive set sealers were tested with Enterococcus faecalis and the viability of human bone marrow-derived mesenchymal stem cells (hMSCs) with this biomaterial was examined. In addition, osteogenic differentiation was highly stimulated, which was confirmed by ALP (Alkaline phosphatase) activity and the ARS (Alizarin red S) staining of hMSCs. The pre-mixed-RCS@BGn satisfied the ISO standards for root canal sealers and maintained antimicrobial activity. Moreover, pre-mixed-RCS@BGn with more BGns turned out to have less cytotoxicity than pre-mixed-RCS without BGns while promoting osteogenic differentiation, mainly due to calcium and silicon ion release. Our results suggest that BGns enhance the biological properties of this calcium silicate-based sealer and that the newly introduced pre-mixed-RCS@BGn has the capability to be applied in dental procedures as a root canal sealer. Further studies focusing more on the biocompatibility of pre-mixed-RCS@BGn should be performed to investigate in vivo systems, including pulp tissue.
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Novel polycaprolactone-based polyurethane (PCL-PU) copolymers with hyperelasticity, shape-memory, and ultra-cell-adhesion properties are reported as clinically applicable tissue-regenerative biomaterials. New isosorbide derivatives (propoxylated or ethoxylated ones) were developed to improve mechanical properties by enhanced reactivity in copolymer synthesis compared to the original isosorbide. Optimized PCL-PU with propoxylated isosorbide exhibited notable mechanical performance (50 MPa tensile strength and 1150% elongation with hyperelasticity under cyclic load). The shape-memory effect was also revealed in different forms (film, thread, and 3D scaffold) with 40%-80% recovery in tension or compression mode after plastic deformation. The ultra-cell-adhesive property was proven in various cell types which were reasoned to involve the heat shock protein-mediated integrin (α5 and αV) activation, as analyzed by RNA sequencing and inhibition tests. After the tissue regenerative potential (muscle and bone) was confirmed by the myogenic and osteogenic responses in vitro, biodegradability, compatible in vivo tissue response, and healing capacity were investigated with in vivo shape-memorable behavior. The currently exploited PCL-PU, with its multifunctional (hyperelastic, shape-memorable, ultra-cell-adhesive, and degradable) nature and biocompatibility, is considered a potential tissue-regenerative biomaterial, especially for minimally invasive surgery that requires small incisions to approach large defects with excellent regeneration capacity.
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Cell reprogramming can satisfy the demands of obtaining specific cell types for applications such as tissue regeneration and disease modeling. Here we report the reprogramming of human fibroblasts to produce chemically-induced osteogenic cells (ciOG), and explore the potential uses of ciOG in bone repair and disease treatment. A chemical cocktail of RepSox, forskolin, and phenamil was used for osteogenic induction of fibroblasts by activation of RUNX2 expression. Following a maturation, the cells differentiated toward an osteoblast phenotype that produced mineralized nodules. Bulk and single-cell RNA sequencing identified a distinct ciOG population. ciOG formed mineralized tissue in an ectopic site of immunodeficiency mice, unlike the original fibroblasts. Osteogenic reprogramming was modulated under engineered culture substrates. When generated on a nanofiber substrate ciOG accelerated bone matrix formation in a calvarial defect, indicating that the engineered biomaterial promotes the osteogenic capacity of ciOG in vivo. Furthermore, the ciOG platform recapitulated the genetic bone diseases Proteus syndrome and osteogenesis imperfecta, allowing candidate drug testing. The reprogramming of human fibroblasts into osteogenic cells with a chemical cocktail thus provides a source of specialized cells for use in bone tissue engineering and disease modeling.