Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 107
Filter
1.
Appl Microbiol Biotechnol ; 108(1): 296, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38607413

ABSTRACT

Sophorolipids (SLs) are promising glycolipid biosurfactants as they are easily produced and functional. SLs from microorganisms are comprised of mixtures of multiple derivatives that have different structures and properties, including well-known acidic and lactonic SL (ASLs and LSLs, respectively). In this study, we established a method for analyzing all SL derivatives in the products of Starmerella bombicola, a typical SL-producing yeast. Detailed component analyses of S. bombicola products were carried out using reversed-phase high-performance liquid chromatography and mass spectrometry. Methanol was used as the eluent as it is a good solvent for all SL derivatives. With this approach, it was possible to not only quantify the ratio of the main components of ASL, LSL, and SL glycerides but also confirm trace components such as SL mono-glyceride and bola-form SL (sophorose at both ends); notably, this is the first time these components have been isolated and identified successfully in naturally occurring SLs. In addition, our results revealed a novel SL derivative in which a fatty acid is bonded in series to the ASL, which had not been reported previously. Using the present analysis method, it was possible to easily track compositional changes in the SL components during culture. Our results showed that LSL and ASL are produced initially and that SL glycerides accumulate from the middle stage during the fermentation process. KEY POINTS: • An easy and detailed component analysis method for sophorolipids (SLs) is introduced. • Multiple SL derivatives were identified different from known SLs. • A novel hydrophobic acidic SL was isolated and characterized.


Subject(s)
Oleic Acids , Saccharomycetales , Fatty Acids , Glycerides
2.
J Craniofac Surg ; 34(7): 2087-2091, 2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37253149

ABSTRACT

This retrospective study aimed to assess the accuracy of prebent plates and computer-aided design and manufacturing osteotomy guide for orthognathic surgery. The prebent plates correspondent to the planning model were scanned with a 3-dimensional printed model for guide design and used for fixation. Forty-two patients who underwent bimaxillary orthognathic surgery using computer-aided design and manufacturing intermediate splint with the guide (guided group: 20 patients) or with conventional fixation under straight locking miniplates (SLMs) technique (SLM group: 20 patients) were analyzed. A deviation of the maxilla between the planned and postoperative positions was evaluated using computed tomography, which was taken 2 weeks before and 4 days after the surgery. The surgery time and the infraorbital nerve paranesthesia were also evaluated. The mean deviations in the mediolateral ( x ), anteroposterior ( y ), and vertical directions ( z ) were 0.25, 0.50, and 0.37 mm, respectively, in the guided group, while that in the SLM group were 0.57, 0.52, and 0.82 mm, respectively. There were significant differences in x and z coordinates ( P <0.001). No significant difference in the surgery duration and paranesthesia was seen, suggesting the present method offers a half-millimeter accuracy for the maxillary repositioning without increasing the risk of extending surgery duration and nerve complication.


Subject(s)
Orthognathic Surgery , Orthognathic Surgical Procedures , Surgery, Computer-Assisted , Humans , Maxilla/diagnostic imaging , Maxilla/surgery , Orthognathic Surgical Procedures/methods , Retrospective Studies , Imaging, Three-Dimensional/methods , Computer-Aided Design , Surgery, Computer-Assisted/methods
3.
Int J Mol Sci ; 24(21)2023 Oct 26.
Article in English | MEDLINE | ID: mdl-37958605

ABSTRACT

The exact mechanisms by which implant surface properties govern osseointegration are incompletely understood. To gain insights into this process, we examined alterations in protein and blood recruitment around screw implants with different surface topographies and wettability using a computational fluid dynamics (CFD) model. Compared with a smooth surface, a microrough implant surface reduced protein infiltration from the outer zone to the implant thread and interface zones by over two-fold. However, the microrough implant surface slowed blood flow in the interface zone by four-fold. As a result, compared with the smooth surface, the microrough surface doubled the protein recruitment/retention index, defined as the mass of proteins present in the area per unit time. Converting implant surfaces from hydrophobic to superhydrophilic increased the mass of protein infiltration 2-3 times and slowed down blood flow by up to two-fold in the implant vicinity for both smooth and microrough surfaces. The protein recruitment/retention index was highest at the implant interface when the implant surface was superhydrophilic and microrough. Thus, this study demonstrates distinct control of the mass and speed of protein and blood flow through implant surface topography, wettability, and their combination, significantly altering the efficiency of protein recruitment. Although microrough surfaces showed both positive and negative impacts on protein recruitment over smooth surfaces, superhydrophilicity was consistently positive regardless of surface topography.


Subject(s)
Dental Implants , Hydrodynamics , Wettability , Osseointegration/physiology , Surface Properties , Prostheses and Implants , Titanium/chemistry
4.
J Oral Implantol ; 48(2): 84-91, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-33760031

ABSTRACT

This study was conducted to determine the most secure implant positioning on the marginally resected mandible to support a fixed complete denture through finite element analysis. Three or 4 implants were placed at near, middle, or far positions from the resected margin in a simulation model with a symmetrical marginal defect in the mandibular symphysis. The height of the residual bone was 5, 10, or 15 mm. The 4 possible implant patterns for 3 or 4 implants were defined as (1) asymmetrically isolated position 1 to position 2, (2) asymmetrically isolated position 1 to position 3, (3) asymmetrically isolated with greater-length position 1 to position 2, and (4) 2 implants symmetrically positioned on each side of the defect. The von Mises stress in the resected and peri-implant bone with respect to the occlusal force was calculated. Initially, because the peri-implant bone stress around the isolated implant at the near position was greater than at the middle and far positions regardless of the residual bone height, the near position was excluded. Second, the von Mises stress in the resected bone region was >10 MPa when the isolated implant was at the far position, and it increased inversely depending on the bone height. However, the stress was <10 MPa when the isolated implant was placed at the middle position regardless of the bone height, and it was significantly lower compared with the far position and equivalent to the symmetrically positioned implants. Furthermore, the use of a greater-length implant reduced peri-implant bone stress, which was even lower than that of the symmetrically positioned implants. These results suggest that the asymmetrically positioned 3-implant-supported fixed denture, using a greater-length isolated implant, placed neither too close to nor too far from the resected margin, can be an effective alternative to the symmetrically positioned 4-implant-supported fixed denture.


Subject(s)
Dental Implants , Dental Prosthesis, Implant-Supported , Computer Simulation , Dental Prosthesis Design , Dental Stress Analysis/methods , Finite Element Analysis , Mandible/surgery , Stress, Mechanical
5.
Int J Mol Sci ; 22(13)2021 Jun 24.
Article in English | MEDLINE | ID: mdl-34202795

ABSTRACT

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.


Subject(s)
Biocompatible Materials , Collagen , Osteogenesis , Titanium , Ultraviolet Rays , Adsorption , Albumins , Animals , Biocompatible Materials/chemistry , Collagen/chemistry , Dental Implants , Diffusion , Hydrophobic and Hydrophilic Interactions , Osseointegration , Osteoblasts/cytology , Osteoblasts/metabolism , Surface Properties , Titanium/chemistry , Wettability
6.
Int J Mol Sci ; 22(22)2021 Nov 17.
Article in English | MEDLINE | ID: mdl-34830275

ABSTRACT

Peri-implantitis is an unsolved but critical problem with dental implants. It is postulated that creating a seal of gingival soft tissue around the implant neck is key to preventing peri-implantitis. The objective of this study was to determine the effect of UV surface treatment of titanium disks on the adhesion strength and retention time of oral connective tissues as well as on the adherence of mucosal fibroblasts. Titanium disks with a smooth machined surface were prepared and treated with UV light for 15 min. Keratinized mucosal tissue sections (3 × 3 mm) from rat palates were incubated for 24 h on the titanium disks. The adhered tissue sections were then mechanically detached by agitating the culture dishes. The tissue sections remained adherent for significantly longer (15.5 h) on the UV-treated disks than on the untreated control disks (7.5 h). A total of 94% of the tissue sections were adherent for 5 h or longer on the UV-treated disks, whereas only 50% of the sections remained on the control disks for 5 h. The adhesion strength of the tissue sections to the titanium disks, as measured by tensile testing, was six times greater after UV treatment. In the culture studies, mucosal fibroblasts extracted from rat palates were attached to titanium disks by incubating for 24, 48, or 96 h. The number of attached cells was consistently 15-30% greater on the UV-treated disks than on the control disks. The cells were then subjected to mechanical or chemical (trypsinization) detachment. After mechanical detachment, the residual cell rates on the UV-treated surfaces after 24 and 48 h of incubation were 35% and 25% higher, respectively, than those on the control surfaces. The remaining rate after chemical detachment was 74% on the control surface and 88% on the UV-treated surface for the cells cultured for 48 h. These trends were also confirmed in mouse embryonic fibroblasts, with an intense expression of vinculin, a focal adhesion protein, on the UV-treated disks even after detachment. The UV-treated titanium was superhydrophilic, whereas the control titanium was hydrophobic. X-ray photoelectron spectroscopy (XPS) chemical analysis revealed that the amount of carbon at the surface was significantly reduced after UV treatment, while the amount of TiOH molecules was increased. These ex vivo and in vitro results indicate that the UV treatment of titanium increases the adhesion and retention of oral mucosa connective tissue as a result of increased resistance of constituent fibroblasts against exogenous detachment, both mechanically and chemically, as well as UV-induced physicochemical changes of the titanium surface.


Subject(s)
Cell Adhesion/radiation effects , Connective Tissue/metabolism , Fibroblasts/metabolism , Mouth Mucosa/metabolism , Titanium/metabolism , Titanium/radiation effects , Ultraviolet Rays , Animals , Carbon/metabolism , Dental Implants , Focal Adhesions/metabolism , Gingiva/cytology , Gingiva/metabolism , Male , Mice , NIH 3T3 Cells , Photoelectron Spectroscopy/methods , Rats , Rats, Sprague-Dawley , Surface Properties/radiation effects , Tensile Strength , Vinculin/metabolism
7.
Int J Mol Sci ; 22(15)2021 Jul 26.
Article in English | MEDLINE | ID: mdl-34360734

ABSTRACT

Biomimetic design provides novel opportunities for enhancing and functionalizing biomaterials. Here we created a zirconia surface with cactus-inspired meso-scale spikes and bone-inspired nano-scale trabecular architecture and examined its biological activity in bone generation and integration. Crisscrossing laser etching successfully engraved 60 µm wide, cactus-inspired spikes on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) with 200-300 nm trabecular bone-inspired interwoven structures on the entire surface. The height of the spikes was varied from 20 to 80 µm for optimization. Average roughness (Sa) increased from 0.10 µm (polished smooth surface) to 18.14 µm (80 µm-high spikes), while the surface area increased by up to 4.43 times. The measured dimensions of the spikes almost perfectly correlated with their estimated dimensions (R2 = 0.998). The dimensional error of forming the architecture was 1% as a coefficient of variation. Bone marrow-derived osteoblasts were cultured on a polished surface and on meso- and nano-scale hybrid textured surfaces with different spike heights. The osteoblastic differentiation was significantly promoted on the hybrid-textured surfaces compared with the polished surface, and among them the hybrid-textured surface with 40 µm-high spikes showed unparalleled performance. In vivo bone-implant integration also peaked when the hybrid-textured surface had 40 µm-high spikes. The relationships between the spike height and measures of osteoblast differentiation and the strength of bone and implant integration were non-linear. The controllable creation of meso- and nano-scale hybrid biomimetic surfaces established in this study may provide a novel technological platform and design strategy for future development of biomaterial surfaces to improve bone integration and regeneration.


Subject(s)
Biomimetic Materials , Cell Differentiation/drug effects , Nanostructures/chemistry , Osteoblasts/metabolism , Osteogenesis/drug effects , Zirconium , Animals , Biomimetic Materials/chemistry , Biomimetic Materials/pharmacology , Cactaceae , Male , Nanostructures/ultrastructure , Osteoblasts/cytology , Rats , Rats, Sprague-Dawley , Zirconium/chemistry , Zirconium/pharmacology
8.
J Oral Maxillofac Surg ; 78(10): 1834.e1-1834.e9, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32428461

ABSTRACT

PURPOSE: The straight locking miniplate (SLM) technique is a straightforward method to accurately reposition the maxilla during bimaxillary orthognathic surgery. The present study evaluated the accuracy of the SLM technique in maintaining the condylar position during surgery without the use of a cutting guide. PATIENTS AND METHODS: The present prospective, single-center study was conducted at Yokohama City University between 2016 and 2017 and included patients with skeletal Class III malocclusion. The patients were divided into 2 groups according to the fixation method used for the mandibular segments. The mandibular segments were fixed with miniplates either manually (manual group) or using the SLM technique (SLM group). Computed tomography was performed before and 3 days after surgery to compare the condylar position. The bodily and rotational movements of the condyle were analyzed. RESULTS: The subjects were 18 Japanese patients (36 condyles) who had undergone bilateral set back surgery with Le Fort I osteotomy. The amount of bodily movements in the manual and SLM groups were 1.44 and 0.62 mm, respectively. The degree of rotational movement in the sagittal plane in the manual and SLM groups was 3.33° and 0.23°, respectively. The bodily and rotational movements in the SLM group were significantly smaller than those in the manual group (P < .05 and P < .01, respectively). CONCLUSIONS: These results suggest that use of the SLM technique reduces the risk of condylar positional changes to less than 1 mm during orthognathic surgery without the use of any complex devices or a cutting guide.


Subject(s)
Malocclusion, Angle Class III , Orthognathic Surgery , Orthognathic Surgical Procedures , Cephalometry , Humans , Malocclusion, Angle Class III/diagnostic imaging , Malocclusion, Angle Class III/surgery , Mandible , Mandibular Condyle/diagnostic imaging , Mandibular Condyle/surgery , Osteotomy, Le Fort , Osteotomy, Sagittal Split Ramus , Prospective Studies
9.
Int J Mol Sci ; 21(12)2020 Jun 12.
Article in English | MEDLINE | ID: mdl-32545509

ABSTRACT

Titanium materials are essential treatment modalities in the medical field and serve as a tissue engineering scaffold and coating material for medical devices. Thus, there is a significant demand to improve the bioactivity of titanium for therapeutic and experimental purposes. We showed that ultraviolet light (UV)-pre-treatment changed the protein-adsorption ability and subsequent osteoconductivity of titanium. Fibronectin (FN) adsorption on UV-treated titanium was 20% and 30% greater after 1-min and 1-h incubation, respectively, than that of control titanium. After 3-h incubation, FN adsorption on UV-treated titanium remained 30% higher than that on the control. Osteoblasts were cultured on titanium disks after 1-h FN adsorption with or without UV-pre-treatment and on titanium disks without FN adsorption. The number of attached osteoblasts during the early stage of culture was 80% greater on UV-treated and FN-adsorbed (UV/FN) titanium than on FN-adsorbed (FN) titanium; osteoblasts attachment on UV/FN titanium was 2.6- and 2.1-fold greater than that on control- and UV-treated titanium, respectively. The alkaline phosphatase activity of osteoblasts on UV/FN titanium was increased 1.8-, 1.8-, and 2.4-fold compared with that on FN-adsorbed, UV-treated, and control titanium, respectively. The UV/FN implants exhibited 25% and 150% greater in vivo biomechanical strength of bone integration than the FN- and control implants, respectively. Bone morphogenetic protein-2 (BMP-2) adsorption on UV-treated titanium was 4.5-fold greater than that on control titanium after 1-min incubation, resulting in a 4-fold increase in osteoblast attachment. Thus, UV-pre-treatment of titanium accelerated its protein adsorptivity and osteoconductivity, providing a novel strategy for enhancing its bioactivity.


Subject(s)
Bone Substitutes/chemistry , Cell Culture Techniques/methods , Mesenchymal Stem Cells/cytology , Osteoblasts/cytology , Titanium/chemistry , Adsorption , Alkaline Phosphatase/metabolism , Animals , Bone Morphogenetic Protein 2/metabolism , Bone Regeneration , Bone Substitutes/radiation effects , Cell Adhesion , Cells, Cultured , Fibronectins/metabolism , Male , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/metabolism , Osteoblasts/metabolism , Rats , Surface Properties , Titanium/radiation effects , Ultraviolet Rays
10.
Int J Mol Sci ; 21(3)2020 Jan 25.
Article in English | MEDLINE | ID: mdl-31991761

ABSTRACT

Titanium implants are the standard therapeutic option when restoring missing teeth and reconstructing fractured and/or diseased bone. However, in the 30 years since the advent of micro-rough surfaces, titanium's ability to integrate with bone has not improved significantly. We developed a method to create a unique titanium surface with distinct roughness features at meso-, micro-, and nano-scales. We sought to determine the biological ability of the surface and optimize it for better osseointegration. Commercially pure titanium was acid-etched with sulfuric acid at different temperatures (120, 130, 140, and 150 °C). Although only the typical micro-scale compartmental structure was formed during acid-etching at 120 and 130 °C, meso-scale spikes (20-50 µm wide) and nano-scale polymorphic structures as well as micro-scale compartmental structures formed exclusively at 140 and 150 °C. The average surface roughness (Ra) of the three-scale rough surface was 6-12 times greater than that with micro-roughness only, and did not compromise the initial attachment and spreading of osteoblasts despite its considerably increased surface roughness. The new surface promoted osteoblast differentiation and in vivo osseointegration significantly; regression analysis between osteoconductivity and surface variables revealed these effects were highly correlated with the size and density of meso-scale spikes. The overall strength of osseointegration was the greatest when the acid-etching was performed at 140 °C. Thus, we demonstrated that our meso-, micro-, and nano-scale rough titanium surface generates substantially increased osteoconductive and osseointegrative ability over the well-established micro-rough titanium surface. This novel surface is expected to be utilized in dental and various types of orthopedic surgical implants, as well as titanium-based bone engineering scaffolds.


Subject(s)
Bone Regeneration , Nanostructures/chemistry , Osseointegration , Titanium/chemistry , Animals , Cell Adhesion , Cell Differentiation , Cells, Cultured , Dental Implants , Male , Nanostructures/ultrastructure , Osteoblasts/cytology , Osteoblasts/metabolism , Prostheses and Implants , Rats , Surface Properties
11.
Int J Mol Sci ; 21(2)2020 Jan 19.
Article in English | MEDLINE | ID: mdl-31963895

ABSTRACT

Ultraviolet treatment of titanium implants makes their surfaces hydrophilic and enhances osseointegration. However, the mechanism is not fully understood. This study hypothesizes that the recruitment of fibrinogen, a critical molecule for blood clot formation and wound healing, is influenced by the degrees of hydrophilicity/hydrophobicity of the implant surfaces. Computational fluid dynamics (CFD) implant models were created for fluid flow simulation. The hydrophilicity level was expressed by the contact angle between the implant surface and blood plasma, ranging from 5° (superhydrophilic), 30° (hydrophilic) to 50° and 70° (hydrophobic), and 100° (hydrorepellent). The mass of fibrinogen flowing into the implant interfacial zone (fibrinogen infiltration) increased in a time dependent manner, with a steeper slope for surfaces with greater hydrophilicity. The mass of blood plasma absorbed into the interfacial zone (blood plasma infiltration) was also promoted by the hydrophilic surfaces but it was rapid and non-time-dependent. There was no linear correlation between the fibrinogen infiltration rate and the blood plasma infiltration rate. These results suggest that hydrophilic implant surfaces promote both fibrinogen and blood plasma infiltration to their interface. However, the infiltration of the two components were not proportional, implying a selectively enhanced recruitment of fibrinogen by hydrophilic implant surfaces.


Subject(s)
Dental Implants , Fibrinogen/metabolism , Plasma/chemistry , Humans , Hydrophobic and Hydrophilic Interactions , Models, Biological , Molecular Dynamics Simulation , Osseointegration , Surface Properties/radiation effects , Titanium , Ultraviolet Rays , Wound Healing
12.
Int J Mol Sci ; 21(3)2020 Jan 23.
Article in English | MEDLINE | ID: mdl-31979313

ABSTRACT

Titanium (Ti) is an osteoconductive material that is routinely used as a bulk implant to fix and restore bones and teeth. This study explored the effective use of Ti as a bone engineering scaffold. Challenges to overcome were: (1) difficult liquid/cell infiltration into Ti microfiber scaffolds due to the hydrophobic nature of Ti; and (2) difficult cell attachment on thin and curved Ti microfibers. A recent discovery of UV-photofunctionalization of Ti prompted us to examine its effect on Ti microfiber scaffolds. Scaffolds in disk form were made by weaving grade 4 pure Ti microfibers (125 µm diameter) and half of them were acid-etched to roughen the surface. Some of the scaffolds with original or acid-etched surfaces were further treated by UV light before cell culture. Ti microfiber scaffolds, regardless of the surface type, were hydrophobic and did not allow glycerol/water liquid to infiltrate, whereas, after UV treatment, the scaffolds became hydrophilic and immediately absorbed the liquid. Osteogenic cells from two different origins, derived from the femoral and mandibular bone marrow of rats, were cultured on the scaffolds. The number of cells attached to scaffolds during the early stage of culture within 24 h was 3-10 times greater when the scaffolds were treated with UV. The development of cytoplasmic projections and cytoskeletal, as well as the expression of focal adhesion protein, were exclusively observed on UV-treated scaffolds. Osteoblastic functional phenotypes, such as alkaline phosphatase activity and calcium mineralization, were 2-15 times greater on UV-treated scaffolds, with more pronounced enhancement on acid-etched scaffolds compared to that on the original scaffolds. These effects of UV treatment were associated with a significant reduction in atomic carbon on the Ti microfiber surfaces. In conclusion, UV treatment of Ti microfiber scaffolds tunes their physicochemical properties and effectively enhances the attachment and function of osteoblasts, proposing a new strategy for bone engineering.


Subject(s)
Osseointegration , Osteoblasts/metabolism , Tissue Scaffolds/chemistry , Titanium/radiation effects , Animals , Bone Marrow Cells/cytology , Calcification, Physiologic/physiology , Cell Culture Techniques , Cells, Cultured , Femur/cytology , Hydrophobic and Hydrophilic Interactions , Male , Mandible/cytology , Microscopy, Electron, Scanning , Osteoblasts/chemistry , Osteoblasts/enzymology , Osteogenesis/physiology , Rats , Rats, Sprague-Dawley , Surface Properties/radiation effects , Tissue Engineering , Titanium/chemistry , Ultraviolet Rays
13.
Int J Mol Sci ; 21(4)2020 Feb 12.
Article in English | MEDLINE | ID: mdl-32059603

ABSTRACT

Effects of UV-photofunctionalization on bone-to-titanium integration under challenging systemic conditions remain unclear. We examined the behavior and response of osteoblasts from sham-operated and ovariectomized (OVX) rats on titanium surfaces with or without UV light pre-treatment and the strength of bone-implant integration. Osteoblasts from OVX rats showed significantly lower alkaline phosphatase, osteogenic gene expression, and mineralization activities than those from sham rats. Bone density variables in the spine were consistently lower in OVX rats. UV-treated titanium was superhydrophilic and the contact angle of ddH2O was ≤5°. Titanium without UV treatment was hydrophobic with a contact angle of ≥80°. Initial attachment to titanium, proliferation, alkaline phosphatase activity, and gene expression were significantly increased on UV-treated titanium compared to that on control titanium in osteoblasts from sham and OVX rats. Osteoblastic functions compromised by OVX were elevated to levels equivalent to or higher than those of sham-operated osteoblasts following culture on UV-treated titanium. The strength of in vivo bone-implant integration for UV-treated titanium was 80% higher than that of control titanium in OVX rats and even higher than that of control implants in sham-operated rats. Thus, UV-photofunctionalization effectively enhanced bone-implant integration in OVX rats to overcome post-menopausal osteoporosis-like conditions.


Subject(s)
Dental Implants , Osseointegration/drug effects , Osteogenesis/drug effects , Osteoporosis , Titanium/pharmacology , Titanium/radiation effects , Ultraviolet Rays , Alkaline Phosphatase , Animals , Bone Density/drug effects , Bone Regeneration/drug effects , Bone and Bones , Calcification, Physiologic/drug effects , Cell Proliferation , Female , Gene Expression , Hydrophobic and Hydrophilic Interactions , Osteoblasts/drug effects , Osteoblasts/pathology , Osteogenesis/genetics , Ovariectomy , Rats , Rats, Sprague-Dawley , Surface Properties
14.
Int J Mol Sci ; 21(7)2020 Mar 31.
Article in English | MEDLINE | ID: mdl-32244335

ABSTRACT

Poly(methyl methacrylate) (PMMA)-based bone cement, which is widely used to affix orthopedic metallic implants, is considered bio-tolerant but lacks osteoconductivity and is cytotoxic. Implant loosening and toxic complications are significant and recognized problems. Here we devised two strategies to improve PMMA-based bone cement: (1) adding 4-methacryloyloxylethyl trimellitate anhydride (4-META) to MMA monomer to render it hydrophilic; and (2) using tri-n-butyl borane (TBB) as a polymerization initiator instead of benzoyl peroxide (BPO) to reduce free radical production. Rat bone marrow-derived osteoblasts were cultured on PMMA-BPO, common bone cement ingredients, and 4-META/MMA-TBB, newly formulated ingredients. After 24 h of incubation, more cells survived on 4-META/MMA-TBB than on PMMA-BPO. The mineralized area was 20-times greater on 4-META/MMA-TBB than PMMA-BPO at the later culture stage and was accompanied by upregulated osteogenic gene expression. The strength of bone-to-cement integration in rat femurs was 4- and 7-times greater for 4-META/MMA-TBB than PMMA-BPO during early- and late-stage healing, respectively. MicroCT and histomorphometric analyses revealed contact osteogenesis exclusively around 4-META/MMA-TBB, with minimal soft tissue interposition. Hydrophilicity of 4-META/MMA-TBB was sustained for 24 h, particularly under wet conditions, whereas PMMA-BPO was hydrophobic immediately after mixing and was unaffected by time or condition. Electron spin resonance (ESR) spectroscopy revealed that the free radical production for 4-META/MMA-TBB was 1/10 to 1/20 that of PMMA-BPO within 24 h, and the substantial difference persisted for at least 10 days. The compromised ability of PMMA-BPO in recruiting cells was substantially alleviated by adding free radical-scavenging amino-acid N-acetyl cysteine (NAC) into the material, whereas adding NAC did not affect the ability of 4-META/MMA-TBB. These results suggest that 4-META/MMA-TBB shows significantly reduced cytotoxicity compared to PMMA-BPO and induces osteoconductivity due to uniquely created hydrophilic and radical-free interface. Further pre-clinical and clinical validations are warranted.


Subject(s)
Bone Cements/pharmacology , Boron Compounds/pharmacology , Free Radicals/pharmacology , Methacrylates/pharmacology , Methylmethacrylates/pharmacology , Osteogenesis/drug effects , Animals , Arthroplasty, Replacement, Hip , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Bone Cements/chemistry , Bone Marrow Cells/drug effects , Bone Regeneration/drug effects , Bone and Bones/drug effects , Bone and Bones/pathology , Boranes , Boron Compounds/chemistry , Calcification, Physiologic/drug effects , Cell Line , Cell Survival/drug effects , Free Radicals/chemistry , Hydrophobic and Hydrophilic Interactions , Male , Materials Testing , Methacrylates/chemistry , Methylmethacrylate/chemistry , Methylmethacrylates/chemistry , Osteoblasts/drug effects , Osteoblasts/pathology , Osteogenesis/genetics , Phenotype , Polymerization , Polymethyl Methacrylate/chemistry , Polymethyl Methacrylate/pharmacology , Prostheses and Implants , Rats , Rats, Sprague-Dawley
15.
Int J Mol Sci ; 20(16)2019 Aug 18.
Article in English | MEDLINE | ID: mdl-31426563

ABSTRACT

Titanium micro-scale topography offers excellent osteoconductivity and bone-implant integration. However, the biological effects of sub-micron topography are unknown. We compared osteoblastic phenotypes and in vivo bone and implant integration abilities between titanium surfaces with micro- (1-5 µm) and sub-micro-scale (0.1-0.5 µm) compartmental structures and machined titanium. The calculated average roughness was 12.5 ± 0.65, 123 ± 6.15, and 24 ± 1.2 nm for machined, micro-rough, and sub-micro-rough surfaces, respectively. In culture studies using bone marrow-derived osteoblasts, the micro-rough surface showed the lowest proliferation and fewest cells attaching during the initial stage. Calcium deposition and expression of osteoblastic genes were highest on the sub-micro-rough surface. The bone-implant integration in the Sprague-Dawley male rat femur model was the strongest on the micro-rough surface. Thus, the biological effects of titanium surfaces are not necessarily proportional to the degree of roughness in osteoblastic cultures or in vivo. Sub-micro-rough titanium ameliorates the disadvantage of micro-rough titanium by restoring cell attachment and proliferation. However, bone integration and the ability to retain cells are compromised due to its lower interfacial mechanical locking. This is the first report on sub-micron topography on a titanium surface promoting osteoblast function with minimal osseointegration.


Subject(s)
Bone-Implant Interface/physiology , Osseointegration , Osteoblasts/drug effects , Titanium/pharmacology , Animals , Cell Proliferation , Cells, Cultured , Male , Osteoblasts/physiology , Rats , Rats, Sprague-Dawley , Titanium/chemistry
16.
J Craniofac Surg ; 29(3): e296-e298, 2018 May.
Article in English | MEDLINE | ID: mdl-29420385

ABSTRACT

Occlusal and esthetic rehabilitation of jaw deformities in patients with partially edentulous maxilla are challenging procedures. This article describes a patient involving a skeletal Class III, 36-year-old male patient with a single bilateral anterior partially edentulous maxilla resulting from injuries sustained in a motor vehicle accident; his anterior teeth had been lost for more than 10 years. His lip protruded from the lateral view due to the proclined upper incisors and mandibular protrusion.Because of the facial deformity and inadequate prosthesis of the maxilla, the prosthesis had dropped out repeatedly. Bone deficiency was prominent in the area of the anterior maxillary region and required augmentation for implant restoration.Consultation among the prosthodontist, orthodontist, and patient led to a decision to perform an orthognathic surgery and bone graft before implant treatment. After orthodontic treatment combined with orthognathic surgery, 3 dental implants were placed with simultaneous iliac bone graft for prosthetic rehabilitation. The treatment restored the maxillary dental arch, which supported the upper lip with appropriate occlusion, both esthetically and functionally. After a 2-year clinical follow-up, the orthoprosthesis of the maxilla remained stable, and the patient was satisfied with the outcome of treatment. The combination of orthodontic, surgical, and dental implant treatment could be an option for skeletal Class III patients with bone-deficient, edentulous jaws.


Subject(s)
Accidents, Traffic , Dental Implants , Maxilla , Orthognathic Surgical Procedures , Adult , Bone Transplantation , Humans , Jaw, Edentulous/surgery , Male , Maxilla/injuries , Maxilla/surgery
17.
Implant Dent ; 27(4): 405-414, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29851661

ABSTRACT

OBJECTIVES: Hydrophilicity/hydrophobicity of titanium surfaces may affect osseointegration. Ordinary titanium surfaces are hydrophobic. Recently, 2 different methods of storing titanium in saline solution or treating it with ultraviolet (UV) light were introduced to generate surface hydrophilicity. This study compared biological and physicochemical properties of 2 different hydrophilic titanium surfaces created by these methods. MATERIALS: Acid-etched control, saline-stored, and UV-treated titanium surfaces were assessed by scanning electron microscopy, energy dispersive spectroscopy, and x-ray photoelectron spectroscopy. The attachment, spreading behaviors, mineralization, and gene expression of osteoblasts were examined. RESULTS: Similar microroughness was found on control and UV-treated surfaces, whereas foreign deposits were observed on saline-stored surfaces. Control and UV-treated surfaces consisted of Ti, O, and C, whereas saline-stored surfaces showed Na and Cl in addition to these 3 elements. Atomic percentage of surface carbon was higher in order of control, saline-stored, and UV-treated surfaces. Osteoblasts cultured on saline-stored surfaces showed higher levels of calcium deposition and collagen I expression than control. Osteoblasts on UV-treated surfaces showed significantly increased levels for all parameters related to cell attachment, cell spreading, the expression of adhesion and cytoskeletal proteins, mineralization, and gene expression compared with control, outperforming saline-stored surfaces for most parameters. CONCLUSION: Despite similar hydrophilicity, saline-stored and UV light-treated surfaces showed substantially different biological effects on osseointegration, associated with different surface chemistry and morphology.


Subject(s)
Osteoblasts/metabolism , Titanium/chemistry , Acid Etching, Dental , Cell Adhesion , Hydrophobic and Hydrophilic Interactions , Microscopy, Electron, Scanning , Osseointegration/physiology , Photoelectron Spectroscopy , Sodium Chloride , Spectrometry, X-Ray Emission , Surface Properties , Ultraviolet Rays
18.
Medicina (Kaunas) ; 54(4)2018 Jul 30.
Article in English | MEDLINE | ID: mdl-30344283

ABSTRACT

Background and objectives: The aim of present study was to compare the treatment results of daily cisplatin (CDDP), weekly docetaxel (DOC) intra-arterial infusion chemotherapy combined with radiotherapy (DIACRT) regimen and weekly CDDP intra-arterial infusion chemotherapy combined with radiotherapy (WIACRT) for patients with tongue cancer. Materials and Methods: Between January 2007 and December 2016, a total of 11 patients treated with WIACRT and 45 patients treated with DIACRT were enrolled in the present study. In the DIACRT group, 25 patients had late T2, and 20 patients had T3. A total of nine patients had late T2 and two had T3 in WIACRT (p = NS). In DIACRT, the treatment schedule consisted of intra-arterial chemotherapy (DOC, total 60 mg/m²; CDDP, total 150 mg/m²) and daily concurrent radiotherapy (RT) (total, 60 Gy). In WIACRT, the treatment schedule consisted of intra-arterial chemotherapy (CDDP, total 360 mg/m²) and daily concurrent RT (total, 60 Gy). Results: The median follow-up periods for DIACRT and WIACRT were 61 and 66 months, respectively. The five-year local control (LC) and overall survival (OS) rate were 94.5% and 89.6% for the DIACRT group, and 60.6% and 63.6% for the WIACRT group, respectively. The LC rate and OS of the DIACRT group were significantly higher than those of the WIACRT group. As regards toxicities, no treatment-related deaths were observed during the follow-up periods in both groups. Conclusions: DIACRT was found to be feasible and effective for patients with tongue cancer and could become a new treatment modality.


Subject(s)
Antineoplastic Agents/therapeutic use , Chemoradiotherapy/methods , Cisplatin/therapeutic use , Docetaxel/therapeutic use , Tongue Neoplasms/therapy , Adult , Aged , Antineoplastic Agents/administration & dosage , Cisplatin/administration & dosage , Cohort Studies , Docetaxel/administration & dosage , Drug Administration Schedule , Feasibility Studies , Female , Humans , Infusions, Intra-Arterial , Male , Middle Aged , Pilot Projects , Retrospective Studies , Survival Rate , Treatment Outcome
19.
J Prosthet Dent ; 118(3): 357-362, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28222880

ABSTRACT

STATEMENT OF PROBLEM: Despite its clinical benefits, the immediate loading protocol might have a higher risk of implant failure than the regular protocol. Ultraviolet (UV) photofunctionalization is a novel surface enhancement technique for dental implants. However, the effect of photofunctionalization under loading conditions is unclear. PURPOSE: The purpose of this animal study was to evaluate the effect of photofunctionalization on the biomechanical quality and strength of osseointegration under loaded conditions in a rat model. MATERIAL AND METHODS: Untreated and photofunctionalized, acid-etched titanium implants were placed into rat femurs. The implants were immediately loaded with 0.46 N of constant lateral force. The implant positions were evaluated after 2 weeks of healing. The strength of osseointegration was evaluated by measuring the bone-implant interfacial breakdown point during biomechanical push-in testing. RESULTS: Photofunctionalization induced hydrophilic surfaces on the implants. Osseointegration was successful in 28.6% of untreated implants and 100% of photofunctionalized implants. The strength of osseointegration in successful implants was 2.4 times higher in photofunctionalized implants than in untreated implants. The degree of tilt of untreated implants toward the origin of force was twice that of photofunctionalized implants. CONCLUSIONS: Within the limit of an animal model, photofunctionalization significantly increased the success of osseointegration and prevented implant tilt. Even for the implants that underwent successful osseointegration, the strength of osseointegration was significantly higher for photofunctionalized implants than for untreated implants. Further experiments are warranted to determine the effectiveness of photofunctionalization on immediately loaded dental implants.


Subject(s)
Dental Implants , Osseointegration/physiology , Osseointegration/radiation effects , Ultraviolet Therapy/methods , Animals , Biomechanical Phenomena , Male , Models, Animal , Rats, Sprague-Dawley , Surface Properties , Weight-Bearing
20.
J Oral Maxillofac Surg ; 74(4): 861.e1-16, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26704430

ABSTRACT

PURPOSE: Ultraviolet-mediated photofunctionalization is a new technology to improve bone and titanium integration. We hypothesized that photofunctionalization would enhance the stability of titanium screws used for segmental bone defects. MATERIALS AND METHODS: Disks were prepared of a titanium alloy (Ti6Al4V) for an in vitro study to evaluate the attachment, proliferation, and differentiation of osteoblasts. Commercially available Ti6Al4V screws were used in vivo. Segmental bone defects were created in rat femurs as an immediate loading reconstruction model. The defects were reconstructed with commercially available titanium plates and Ti6Al4V screws, with or without photofunctionalization. The screw survival rates and mechanical stability were evaluated at 2 and 4 weeks, and the bone formation around the screws was analyzed. RESULTS: Osteoblasts showed greater attachment, proliferation, and differentiation on the photofunctionalized Ti6Al4V disks. Photofunctionalized screws had significantly greater survival rates and mechanical stability at 2 and 4 weeks. The bone formation around the photofunctionalized screws was significantly greater than that around the untreated screws at 4 weeks. CONCLUSIONS: The results of the present study have demonstrated the efficacy of photofunctionalization on enhancing the survival and stability of Ti6Al4V screws under a loaded condition in the reconstruction of segmental defects. This was associated with increased bioactivity and bone formation around the photofunctionalized Ti6Al4V material.


Subject(s)
Alloys/radiation effects , Biocompatible Materials/radiation effects , Bone Screws , Bone-Implant Interface/radiation effects , Femur/surgery , Titanium/radiation effects , Ultraviolet Rays , Alloys/chemistry , Animals , Biocompatible Materials/chemistry , Bone Diseases/surgery , Bone Plates , Cell Adhesion/physiology , Cell Differentiation/physiology , Cell Proliferation/physiology , Cells, Cultured , Male , Materials Testing , Microscopy, Electron, Scanning , Osteoblasts/physiology , Osteogenesis/physiology , Rats , Rats, Sprague-Dawley , Plastic Surgery Procedures/instrumentation , Spectrometry, X-Ray Emission , Stress, Mechanical , Survival Analysis , Time Factors , Titanium/chemistry
SELECTION OF CITATIONS
SEARCH DETAIL