A novel porcine acellular dermal matrix scaffold used in periodontal regeneration

Regeneration of periodontal tissue is the most promising method for restoring periodontal structures.To find a suitable bioactive three- dimensional scaffold promoting cell proliferation and differentiation is critical in periodontal tissue engineering.The objective of this study was to evaluate the biocompatibility of a novel porcine acellular dermal matrix as periodontal tissue scaffolds both in vitro and in vivo.The scaffolds in this study were purified porcine acellular dermal matrix(PADM) and hydroxyapatite-treated PADM(HA-PADM). The biodegradation patterns of the scaffolds were evaluated in vitro.The biocompatibility of the scaffolds in vivo was assessed by implanting them into the sacrospinal muscle of 20 New Zealand white rabbits.The hPDL cells were cultured with PADM or HA-PADM scaffolds for 3,7,14,21 and 28 days.Cell viability assay,scanning electron microscopy(SEM),hematoxylin and eosin(H&E) staining, immunohistochemistry and confocal microscopy were used to evaluate the biocompatibility of the scaffolds.In vitro,both PADM and HA-PADM scaffolds displayed appropriate biodegradation pattern,and also,demonstrated favorable tissue compatibility without tissue necrosis,fibrosis and other abnormal response.The absorbance readings of the WST-1 assay were increased with the time course, suggesting the cell proliferation in the scaffolds.The hPDL cells attaching,spreading and morphology on the surface of the scaffold were visualized by SEM,H&E staining,immnuohjstochemistry and confocal microscopy,demonstrated that hPDL cells were able to grow into the HA-PADM scaffolds and the amount of cells were growing up in the course of time.This study proved that HA-PADM scaffold had good biocompatibility in animals in vivo and appropriate biodegrading characteristics in vitro.The hPDL cells were able to proliferate and migrate into the scaffold.These observations may suggest that HA-PADM scaffold is a potential cell carrier for periodontal tissue regeneration.

The recent advances in scaffolds for integrated periodontal regeneration

The periodontium is an integrated,functional unit of multiple tissues surrounding and supporting the tooth,including but not limited to cementum(CM),periodontal ligament(PDL)and alveolar bone(AB).Periodontal tissues can be destructed by chronic periodontal disease,which can lead to tooth loss.In support of the treatment for periodontally diseased tooth,various biomaterials have been applied starting as a contact inhibition membrane in the guided tissue regeneration(GTR)that is the current gold standard in dental clinic.Recently,various biomaterials have been prepared in a form of tissue engineering scaffold to facilitate the regeneration of damaged periodontal tissues.From a physical substrate to support healing of a single type of periodontal tissue to multi-phase/bioactive scaffold system to guide an integrated regeneration of periodontium,technologies for scaffold fabrication have emerged in last years.This review covers the recent advancements in development of scaffolds designed for periodontal tissue regeneration and their efficacy tested in vitro and in vivo.Pros and Cons of different biomaterials and design parameters implemented for periodontal tissue regeneration are also discussed,including future perspectives.

Local icariin application enhanced periodontal tissue regeneration and relieved local inflammation in a minipig model of periodontitis

Periodontitis is an inflammatory autoimmune disease. Treatment should alleviate inflammation, regulate the immune reaction and promote periodontal tissue regeneration. Icariin is the main active ingredient of Epimedii Folium, and it is a promising compound for the enhancement of mesenchymal stem cell function, promotion of bone formation, inhibition of bone resorption, alleviation of inflammation and regulation of immunity. The study investigated the effect of icariin on periodontal tissue regeneration in a minipig model of periodontitis. The minipig model of periodontitis was established. Icariin was injected locally. The periodontal clinical assessment index, a computed tomography(CT) scan, histopathology and enzyme-linked immune sorbent assay(ELISA)were used to evaluate the effects of icariin. Quantitative analysis results 12 weeks post-injection demonstrated that probing depth,gingival recession, attachment loss and alveolar bone regeneration values were(3.72 ± 1.18) mm vs.(6.56 ± 1.47) mm,(1.67 ± 0.59)mm vs.(2.38 ± 0.61) mm,(5.56 ± 1.29) mm vs.(8.61 ± 1.72) mm, and(25.65 ± 5.13) mm3 vs.(9.48 ± 1.78) mm3 in the icariin group and0.9% NaCl group, respectively. The clinical assessment, CT scan, and histopathology results demonstrated significant enhancement of periodontal tissue regeneration in the icariin group compared to the 0.9% NaCl group. The ELISA results suggested that the concentration of interleukin-1 beta(IL-1β) in the icariin group was downregulated compared to the 0.9% NaCl group, which indicates that local injection of icariin relieved local inflammation in a minipig model of periodontitis. Local injection of icariin promoted periodontal tissue regeneration and exerted anti-inflammatory and immunomodulatory function. These results support the application of icariin for the clinical treatment of periodontitis.

Research progress of strontium in promoting periodontal tissue regeneration

Periodontal disease is a chronic infectious disease of the oral cavity.Its main clinical features are periodontal pocket formation and alveolar bone resorption.Scholars'research hotspot is to achieve periodontal tissue regeneration in patients.Studies have found that strontium has certain potential in promoting periodontal tissue regeneration.In recent years,scholars have been conducting research on strontium and periodontal tissue regeneration,with a view to opening a new path for periodontal disease treatment.This article reviews the research status of strontium and periodontal tissue regeneration.The review results show that strontium can induce the proliferation and differentiation of PDLSCs and promote the regeneration of lost bone tissue;it can inhibit osteoclast activity and induce osteoclast apoptosis through a variety of signaling pathways,thereby inhibiting bone resorption;Promote bone formation;Strontium also has the function of promoting early angiogenesis and suppressing immune inflammatory response.Because the current research on strontium and periodontal tissue regeneration is only focused on in vivo and in vitro experiments,there is no relevant clinical trial to apply strontium to periodontal tissue regeneration.Therefore,if strontium is used to promote periodontal tissue regeneration to achieve the treatment of periodontal disease,further research is needed.

Effectiveness of two regeneration materials in autogenous tooth transplantation in larger sockets:an experimental study in beagle dogs

Objective： To evaluate the effectiveness of regenerous tissue and bone substitute in autogenous tooth transplantation in the larger recipient socket. Methods：In 3 Beagle dogs, 18 incisors were transplanted to the recipient sockets, 2 mm wider mesio-distally. The regenerous tissue group, the bone substitute group and the control group contained 7, 7 and 4 teeth respectively. No additional material was used in control group. Clinical and radiographic examinations were done every month and were sacrificed 3 months later. Subsequently, decalcified sections were prepared for routine histological evaluation. Ordinal scores for root surface resorption were analyzed using the Kruskal-Wallis test. Results：All donor teeth survived. A statistically significant difference was found among all three treatment groups（P= 0.0001）. The proliferating tissue in space positively affected the periodontal healing without any resorption. Inflammatory resorption of the root surface and formation of new bone were observed in the bone substitute group. Surface resorptions of the roots were found in the control group. Conclusion：Proliferating tissues enhance the regeneration of periodontal tissues in larger recipient sockets and prevent root resorption. Sinbone HT is beneficial for the stabilization of the transplanted teeth in larger sockets.

Tissue-specific melt electrowritten polymeric scaffolds for coordinated regeneration of soft and hard periodontal tissues

Periodontitis is a chronic inflammatory condition that often causes serious damage to tooth-supporting tissues.The limited successful outcomes of clinically available approaches underscore the need for therapeutics that cannot only provide structural guidance to cells but can also modulate the local immune response.Here,three-dimensional melt electrowritten(i.e.,poly(ε-caprolactone))scaffolds with tissue-specific attributes were engineered to guide differentiation of human-derived periodontal ligament stem cells(hPDLSCs)and mediate macrophage polarization.The investigated tissue-specific scaffold attributes comprised fiber morphology(aligned vs.random)and highly-ordered architectures with distinct strand spacings(small 250μm and large 500μm).Macrophages exhibited an elongated morphology in aligned and highly-ordered scaffolds,while maintaining their round-shape on randomly-oriented fibrous scaffolds.Expressions of periostin and IL-10 were more pronounced on the aligned and highly-ordered scaffolds.While hPDLSCs on the scaffolds with 500μm strand spacing show higher expression of osteogenic marker(Runx2)over 21 days,cells on randomly-oriented fibrous scaffolds showed upregulation of M1 markers.In an orthotopic mandibular fenestration defect model,findings revealed that the tissue-specific scaffolds(i.e.,aligned fibers for periodontal ligament and highly-ordered 500μm strand spacing fluorinated calcium phosphate[F/CaP]-coated fibers for bone)could enhance the mimicking of regeneration of natural periodontal tissues.

An Overview of the Use of Medicinal Plants in Regenerative Dentistry

Aim: The oral cavity has the particularity to host multiple hard and soft tissues, in this paper, we will discuss the current therapies that lead to cell differentiation by regenerative therapies and the future alternatives proposed by medicinal plants and all the regenerative potential of these different tissues. Material and Methods: A detailed review of the literature through the various search engines: Scopus, PubMed, google scholar, Cochrane, etc., uses the selected keywords to explore the effect of the regenerative potential of several medicinal plants. Results: Through our research, we have proceeded to sort different medicinal plants, according to their repairing and regenerative potential on the different tissues of the oral cavity. Conclusion: Future studies are conceivable to explore the opportunities and potential provided by medicinal plants in the field of regenerative dentistry.

In Vitro Evaluation of Two Tissue Substitutes for Gingival Augmentation

Three-dimensional collagen matrices of porcine origin are being used as substitutes for soft tissue grafts in periodontal plastic surgery in search of aesthetic and natural results. This in vitro study aimed to compare Fibro-Gide® (GeistlichBiomaterials) and Mucoderm® (BotissBiomaterials) matrices during the initial phase of soft tissue formation. For this purpose, samples of 5 × 5 mm were obtained, and then human fibroblasts were plated on them. After 24, 48 and 72 h, cell viability was assessed using an MTT assay, and the secretion of type I collagen, MMP-2, TIMP-1 and TIMP-2 was analyzed by ELISA immunoassay. The control group (C) consisted of cells plated on polystyrene without the matrices. The morphology of the surfaces was also examined using scanning electron microscopy (SEM), as was the average roughness (Ra) of the samples by a profilometer. Topographic analysis revealed that roughness was significantly higher on Mucoderm® than on Fibro-Gide® (p 0.05). The synthesis of type I collagen, MMP-2 and TIMP-1 were significantly higher from cells plated on Fibro-Gide® than on Mucoderm®, in all time points (p ® than on Mucoderm® (p ® induced an increase in type I collagen, MMP-2 and TIMP-1 and TIMP-2.

Bioinspired drug-delivery system emulating the natural bone healing cascade for diabetic periodontal bone regeneration

Diabetes mellitus(DM)aggravates periodontitis,resulting in accelerated periodontal bone resorption.Disordered glucose metabolism in DM causes reactive oxygen species(ROS)overproduction resulting in compromised bone healing,which makes diabetic periodontal bone regeneration a major challenge.Inspired by the natural bone healing cascade,a mesoporous silica nanoparticle(MSN)-incorporated PDLLA(poly(DL-lactide))-PEG-PDLLA(PPP)thermosensitive hydrogel with stepwise cargo release is designed to emulate the mesenchymal stem cell“recruitment-osteogenesis”cascade for diabetic periodontal bone regeneration.During therapy,SDF-1 quickly escapes from the hydrogel due to diffusion for early rat bone marrow stem cell(rBMSC)recruitment.Simulta-neously,slow degradation of the hydrogel starts to gradually expose the MSNs for sustained release of metformin,which can scavenge the overproduced ROS under high glucose conditions to reverse the inhibited osteogenesis of rBMSCs by reactivating the AMPK/β-catenin pathway,resulting in regulation of the diabetic microenvironment and facilitation of osteogenesis.In vitro experiments indicate that the hydrogel markedly restores the inhibited migration and osteogenic capacities of rBMSCs under high glucose conditions.In vivo results suggest that it can effectively recruit rBMSCs to the periodontal defect and significantly promote periodontal bone regeneration under type 2 DM.In conclusion,our work provides a novel therapeutic strategy of a bioinspired drug-delivery system emulating the natural bone healing cascade for diabetic periodontal bone regeneration.

Dimethyloxallyl glycine/nanosilicates-loaded osteogenic/angiogenic difunctional fibrous structure for functional periodontal tissue regeneration

The coupled process of osteogenesis-angiogenesis plays a crucial role in periodontal tissue regeneration.Although various cytokines or chemokines have been widely applied in periodontal in situ tissue engineering,most of them are macromolecular proteins with the drawbacks of short effective half-life,poor stability and high cost,which constrain their clinical translation.Our study aimed to develop a difunctional structure for periodontal tissue regeneration by incorporating an angiogenic small molecule,dimethyloxalylglycine(DMOG),and an osteoinductive inorganic nanomaterial,nanosilicate(nSi)into poly(lactic-co-glycolic acid)(PLGA)fibers by electrospinning.The physiochemical properties of DMOG/nSi-PLGA fibrous membranes were characterized.Thereafter,the effect of DMOG/nSi-PLGA membranes on periodontal tissue regeneration was evaluated by detecting osteogenic and angiogenic differentiation potential of periodontal ligament stem cells(PDLSCs)in vitro.Additionally,the fibrous membranes were transplanted into rat periodontal defects,and tissue regeneration was assessed with histological evaluation,micro-computed tomography(micro-CT),and immunohistochemical analysis.DMOG/nSi-PLGA membranes possessed preferable mechanical property and biocompatibility.PDLSCs seeded on the DMOG/nSi-PLGA membranes showed up-regulated expression of osteogenic and angiogenic markers,higher alkaline phosphatase(ALP)activity,and more tube formation in comparison with single application.Further,in vivo study showed that the DMOG/nSi-PLGA membranes promoted recruitment of CD90+/CD34stromal cells,induced angiogenesis and osteogenesis,and regenerated cementum-ligament-bone complex in periodontal defects.Consequently,the combination of DMOG and nSi exerted admirable effects on periodontal tissue regeneration.DMOG/nSi-PLGA fibrous membranes could enhance and orchestrate osteogenesis-angiogenesis,and may have the potential to be translated as an effective scaffold in periodontal tissue engineering.

Application of Induced Pluripotent Stem Cells Derived from Human Periodontal Ligament Cells in Bone Regeneration

The purpose of this study was to primarily culture human periodontal ligament cells(hPDLCs)and to reprogram hPDLCs with exogenous genes via a lentivirus-mediated transfection system.Then induced pluripotent stem cells derived from h PDLCs(hPDLC-iPSCs)were identified.Alizarin red staining was used to observe the formation of mineralized nodules and real-time Polymerase Chain Reaction(PCR)was used to detect the expression of osteogenic genes.For the in vivo experiment,nude mouse skull defect models were established and cell sheets were made to repair the bone defect.The reprogrammed cells were positive for alkaline phosphatase(ALP)staining and embryonic stem cells(ESCs)-specific proteins,and could form teratomas.After osteogenic induction,alizarin red staining showed that the number of mineralized nodules in the h PDLC-i PSCs group was more and the osteogenic related factors ALP,osteocalcin(OCN),Col-I and Runx2 were also expressed higher in hPDLC-iPSCs.The hPDLC-iPSC cell sheets were all successfully made.Histological analysis showed that the h PDLC-i PSC cell sheet got new bone formation.These results demonstrated that hPDLC-iPSCs were successfully generated from human periodontal ligament fibroblasts and hPDLC-iPSC cell sheets provided new options for bone tissue engineering.

PREPARATION OF CHITOSAN/HYDROXYAPATITE GUIDED MEMBRANE USED FOR PERIODONTAL TISSUE REGENERATION

In an effort to develop biomaterials to meet guided tissue regeneration （GTR） standards for periodontal tissue recovery, a homogeneous and transparent chitosan （CS）/hydroxyapatite （HA） membrane with potential applications as GTR barrier in periodontal therapy has been prepared via in situ compositing. The membrane has been designed to have a smoothrough asymmetric structure that meets the demand for GTR. Component and morphology of the membrane are characterized by XRD and SEM. It can be indicated that HA was in situ synthesized uniformly in the CS membrane. Mechanical experiments of the membranes with various HA contents show that their tensile strengths are adequate for periodontal therapy. Biological properties of the membrane have been performed by cell toxicity assays, hemolysis tests and animal experiments. Results indicate that the membrane has good biocompatibility and inductive effect for cell growth. Therefore this membrane can be potentially applied as GTR barrier membrane for periodontal tissue regeneration.

A viscoelastic alginate-based hydrogel network coordinated with spermidine for periodontal ligament regeneration

Periodontitis can cause irreversible defects in the periodontal ligament(PDL),the regeneration of which is the major obstacle to the clinical treatment of periodontitis.Implanting hydrogel for releasing anti-inflammatory drugs is a promising treatment to promote PDL regeneration.However,existing hydrogel systems fail to mimic the typical viscoelastic feature of native periodontium,which may have been shown as an important role in tissue regeneration.Meanwhile,the synergistic benefits of mechanical cues and biochemical agents for PDL regeneration remain elusive.In this study,we developed a bi-crosslinking viscoelastic hydrogel(Alg-PBA/Spd)by integrating phenylboronic acid-modified alginate with anti-inflammatory agent(spermidine)through borate ester and B-N coordination bonds,where spermidine will be released with the degradation of the hydrogel.Alg-PBA/Spd hydrogel is biocompatible,injectable and can quickly adapt to complex periodontal structures due to the dynamic crosslinking.We demonstrated in rat models that the viscoelastic Alg-PBA/Spd hydrogel significantly promotes the deposition of periodontal collagen and accelerates the repair of periodontal damage.Our results suggest that the viscoelastic Alg-PBA/Spd hydrogel would be a promising mechano-biochemically synergistic treatment for periodontal regeneration.

Functional biomaterials for comprehensive periodontitis therapy

Periodontitis is an inflammatory disease caused by bacterial infection directly, and the dysregulation of host immune-inflammatory response finally destroys periodontal tissues. Current treatment strategies for periodontitis mainly involve mechanical scaling/root planing(SRP), surgical procedures,and systemic or localized delivery of antimicrobial agents. However, SRP or surgical treatment alone has unsatisfactory long-term effects and is easy to relapse. In addition, the existing drugs for local periodontal therapy do not stay in the periodontal pocket long enough and have difficulties in maintaining a steady, effective concentration to obtain a therapeutic effect, and continuous administration always causes drug resistance. Many recent studies have shown that adding bio-functional materials and drug delivery systems upregulates the therapeutic effectiveness of periodontitis. This review focuses on the role of biomaterials in periodontitis treatment and presents an overview of antibacterial therapy, host modulatory therapy, periodontal regeneration, and multifunctional regulation of periodontitis therapy. Biomaterials provide advanced approaches for periodontal therapy, and it is foreseeable that further understanding and applications of biomaterials will promote the development of periodontal therapy.

Effect of platelet-rich plasma in the treatment of periodonta intrabony defects in humans

Background Platelet-rich plasma （PRP） is a kind of natural source of autologous growth factors, and has been used successfully in medical community. However, the effect of PRP in periodontal regeneration is not clear yet. This study was designed to evaluate the effectiveness of PRP as an adjunct to bovine porous bone mineral （BPBM） graft in the treatment of human intrabony defects. Methods Seventeen intrabony defects in 10 periodontitis patients were randomly treated either with PRP and BPBM （test group, n=9） or with BPBM alone （control group, n=8）. Clinical parameters were evaluated including changes in probing depth, relative attachment level （measured by Florida Probe and a stent）, and bone probing level between baseline and 1 year postoperatively. Standardized periapical radiographs of each defect were taken at baseline, 2 weeks, and 1 year postoperatively, and analyzed by digital subtraction radiography （DSR）. Results Both treatment modalities resulted in significant attachment gain, reduction of probing depth, and bone probing level at 1-year post-surgery compared to baseline. The test group exhibited statistically significant improvement compared to the control sites in probing depth reduction： （4.78± 0.95） mm versus （3.48 ± 0.41） mm （P〈0.01）; clinical attachment gain： （4.52± 1.14） mm versus （2.85 ± 0.80） mm （P〈0.01）; bone probing reduction： （4.56±1.04） mm versus （2.88±0.79） turn （P〈0.01）; and defect bone fill： （73.41± 14.78）% versus （47.32± 11.47）% （P〈0.01）. DSR analysis of baseline and 1 year postoperatively also showed greater radiographic gains in alveolar bone mass in the test group than in the control group： gray increase （580±50） grays versus （220± 32） grays （P=0.0001）; area with increased gray were （5.21± 1.25） mm^2 versus （3.02± 1.22） mm^2 （P=0.0001）.Conclusions The treatment with a combination of PRP and BPBM led to a significantly favorable clinical improvement in periodontal intrabony defects compared to using BPBM alone. Further studies are necessary to assess the long-term effectiveness of PRP, and a larger sample size is needed.

Effects of secretive bone morphogenetic protein 2 induced by gene transfection on the biological changes of NIH3T3 cells

Background Bone morphogenetic proteins （BMPs）, which belong to the transforming growth factor beta superfamily, are powerful regulators of cartilage and bone formation. This study investigated the biological changes of NIH3T3 ceils incubated with secretive BMP2 that was induced by gene transfection through transwell.Methods Eukaryonic expression vector （pcDNA3. 1-B2 ） was transfered into NIH333 cells with Sofast^TM, a positive compound transfection agent. The positive cell clones were selected with G418. The cytoplasmic and extracellular expressions of BMP2 were determined by immunohistochemical stain and enzyme-linked immunosorbent assay. NIH333 ceils were co-cultured with hBMP2 gene transfecting ceils through transwell, and the ultrastructure, alkaline phosphatase activity and the expression of osteocalcin （the marker of osteogenetic differentiation） changes were observed.Results There were cytoplasmic and extracellular expressions of BMP2 in transfecting NIH3T3 ceils. The ultrastructural changes, the high activity of alkaline phosphatase and the positive stain of osteocalcin suggested the osteogenetic differentiation tendency of NIH3T3 cells co-cultured with transfecting NIH3T3 cells.Conclusion Secretive BMP2 that is induced by gene transfection could promote the osteogenetic differentiation of fibroblast ceils.