Acemannan sponges stimulate alveolar bone, cementum and periodontal ligament regeneration in a canine class II furcation defect model

Potential applications of medicinal herbs and phytochemicals in oral and dental health: Status quo and future perspectives

OBJECTIVE

Herbal therapies are utilized to treat a broad diversity of diseases all over the globe. Although no clinical studies have been conducted to demonstrate the antibacterial, antimicrobial, and antiplaque characteristics of these plants, this does not imply that they are ineffectual as periodontal treatments or anti-cariogenic drugs. However, there is a scarcity of research confirming their efficacy and worth.

SUBJECT

Herbs are utilized in dentistry as antimicrobial, antineoplastic, antiseptic, antioxidant, and analgesics agents as well as for the elimination of bad breath. In addition, the application of herbal agents in tissue engineering improved the regeneration of oral and dental tissues. This study reviews the application of medicinal herbs for the treatment of dental and oral diseases in different aspects.

METHODS

This article focuses on current developments in the use of medicinal herbs and phytochemicals in oral and dental health. An extensive literature review was conducted via an Internet database, mostly PubMed. The articles included full-text publications written in English without any restrictions on a date.

CONCLUSION

Plants have been suggested, as an alternate remedy for oral-dental problems, and this vocation needs long-term dependability. More research on herbal medicine potential as pharmaceutical sources and/or therapies is needed.

Synthetic Calcium-Phosphate Materials for Bone Grafting

Synthetic bone grafting materials play a significant role in various medical applications involving bone regeneration and repair. Their ability to mimic the properties of natural bone and promote the healing process has contributed to their growing relevance. While calcium-phosphates and their composites with various polymers and biopolymers are widely used in clinical and experimental research, the diverse range of available polymer-based materials poses challenges in selecting the most suitable grafts for successful bone repair. This review aims to address the fundamental issues of bone biology and regeneration while providing a clear perspective on the principles guiding the development of synthetic materials. In this study, we delve into the basic principles underlying the creation of synthetic bone composites and explore the mechanisms of formation for biologically important complexes and structures associated with the various constituent parts of these materials. Additionally, we offer comprehensive information on the application of biologically active substances to enhance the properties and bioactivity of synthetic bone grafting materials. By presenting these insights, our review enables a deeper understanding of the regeneration processes facilitated by the application of synthetic bone composites.

Biopolymer collagen-chitosan scaffold containing Aloe vera for chondrogenic efficacy on cartilage tissue engineering

The chondrogenic efficacy of aloe vera blended collagen-chitosan (COL-CS-AV) porous scaffold was investigated using articular chondrocytes in a standard condition. Cytocompatibility was analyzed using fluorescent dyes (calcein AM/ethidium bromide) and the viable cells were quantified by MTT assay. Glycosaminoglycan (GAG) content of ECM was estimated by using 1, 9-Dimethyl methylene Blue (DMMB). The total RNA content was quantified and the cartilage specific genes (col2a1, Acan) were amplified by reverse transcription-PCR from the cell lysate of the scaffolds. Histological examination was made using Haematoxylin and Eosin (H&E), safranin-O, masson's trichrome, alcian blue, and alizarin red to stain the specific component of ECM secreted on the construct. The cartilage specific collagen type II was estimated by immunohistochemistry using monoclonal type II collagen antibody. The results of these studies proved that COL-CS-AV scaffold has more chondrogenic efficacy than COL-CS, thus the aloe vera blend COL-CS-AV scaffold might be used as suitable candidate for cartilage tissue engineering.

A New Biomaterial Derived from Aloe vera-Acemannan from Basic Studies to Clinical Application

Aloe vera is a kind of herb rich in polysaccharides. Acemannan (AC) is considered to be a natural polysaccharide with good biodegradability and biocompatibility extracted from Aloe vera and has a wide range of applications in the biomedical field due to excellent immunomodulatory, antiviral, antitumor, and tissue regeneration effects. In recent years, clinical case reports on the application of AC as a novel biomedical material in tissue regenerative medicine have emerged; it is mainly used in bone tissue engineering, pulp-dentin complex regeneration engineering, and soft tissue repair, among other operations. In addition, multiple studies have proved that the new composite products formed by the combination of AC and other compounds have excellent biological and physical properties and have broader research prospects. This paper introduces the preparation process, surface structure, and application forms of AC; summarizes the influence of acetyl functional group content in AC on its functions; and provides a detailed review of the functional properties, laboratory studies, clinical cutting-edge applications, and combined applications of AC. Finally, the current application status of AC from basic research to clinical treatment is analyzed and its prospects are discussed.

Histologic and histomorphometric evaluation of Aloe vera adjunctive to β-tricalcium phosphate in class II furcation defects in dogs

Aloe vera has antimicrobial activity and enhances the osseointegration process, thus it may have the potential in treating periodontal defects. This study aimed to evaluate the effect of Aloe vera as an adjunction to Beta-tricalcium phosphate (β-TCP) bone graft in Grade II furcation defects. A randomized study was conducted on six healthy mongrel dogs' premolars. A total of twenty-four Grade II furcation critical-sized defects were surgically created after reflecting a full-thickness flap, twelve defects were filled with β-TCP while the other twelve defects were filled with Aloe vera mixed with β-TCP and both covered by collagen membrane. Animals were euthanized at the end of the fourth and eighth week and defects were analyzed histologically and histomorphometrically. Histologically, Aloe vera mixed with β-TCP resulted in more bone formation and new PDL fibers compared to β-TCP alone. After 2 and 4 weeks, the experimental group had significantly higher newly formed interradicular bone height (p < 0.0001, and p < 0.0001, respectively), bone thickness (p < 0.0001, and p < 0.0001, respectively), and percentage of the surface area (p = 0.009, and p = 0.023, respectively). Aloe vera gel adjunctive to β-TCP is an effective bioactive agent that enhances periodontal tissue regeneration and bone formation in critically sized defects.

Clinical and Radiographic Evaluation of Combined Acemannan and Periodontal Surgery Induced-Periodontal Regeneration: 5-Year Follow-up Case Report

Background and Objective:

Acemannan, a polysaccharide extracted from aloe vera gel, accelerates oral wound healing, reparative dentin formation, and bone formation in extraction sockets. In this report, we evaluated the efficacy of combined acemannan and periodontal surgery on periodontal regeneration in severe periodontitis cases requiring periodontal surgery.

Case Presentation and Discussion:

Three chronic periodontitis patients with probing pocket depths of at least 6 mm and two- or three-walled vertical bone defects after initial periodontal therapy were included. The patients underwent minimally invasive periodontal surgery with acemannan sponges placed in the defect. Maintenance recall was scheduled every 6 months for 5 years. Clinical and radiographic evaluations were performed to assess the effects of the combined acemannan and periodontal surgery on periodontal regeneration. The patients demonstrated improved clinical parameters and increased radiographic bone fill at the 5-year follow-ups. The percentage bone fill in the three-walled defect, combined two- and three-walled defect, and two-walled defect cases were 70%, 60%, and 20%, respectively. The underlying mechanism of action of acemannan in periodontal regeneration was also discussed.

Conclusion:

Acemannan sponges can be used as an adjunct to periodontal surgery for periodontal regeneration.

Beneficial Effects of a Blended Fibroin/Aloe Gel Extract Film on the Biomolecular Mechanism(s) via the MAPK/ERK Pathway Relating to Diabetic Wound Healing

In diabetic patients, the process of wound healing is usually delayed or impaired. A diabetic environment could be associated with dermal fibroblast dysfunction, reduced angiogenesis, the release of excessive proinflammatory cytokines, and senescence features. Alternative therapeutic treatments using natural products are highly demanded for their high potential of bioactive activity in skin repair. Two natural extracts were combined to develop fibroin/aloe gel wound dressing. Our previous studies revealed that the prepared film enhances the healing rate of diabetic foot ulcers (DFUs). Moreover, we aimed to explore its biological effects and underlying biomolecular mechanisms on normal dermal, diabetic dermal, and diabetic wound fibroblasts. Cell culture experiments showed that the γ-irradiated blended fibroin/aloe gel extract film promotes skin wound healing by enhancing cell proliferation and migration, vascular epidermal growth factor (VEGF) secretion, and cell senescence prevention. Its action was mainly linked to the activation of the mitogen-activated protein kinases/extracellular signal-regulated kinase (MAPK/ERK) signaling pathway known to regulate various cellular activities, including proliferation. Therefore, the findings of this study confirm and support our previous data. The blended fibroin/aloe gel extract film displays a biological behavior with favorable properties for delayed wound healing and can be considered as a promising therapeutic approach in the treatment of diabetic nonhealing ulcers.

Amelogenin-Derived Peptide (ADP-5) Hydrogel for Periodontal Regeneration: An In Vitro Study on Periodontal Cells Cytocompatibility, Remineralization and Inflammatory Profile

A relevant alternative to enamel matrix derivatives from animal origin could be the use of synthetic amelogenin-derived peptides. This study aimed to assess the effect of a synthetic amelogenin-derived peptide (ADP-5), alone or included in an experimental gellan-xanthan hydrogel, on periodontal cell behavior (gingival fibroblasts, periodontal ligament cells, osteoblasts and cementoblasts). The effect of ADP-5 (50, 100, and 200 µg/mL) on cell metabolic activity was examined using Alamar blue assay, and cell morphology was assessed by confocal imaging. An experimental gellan-xanthan hydrogel was then designed as carrier for ADP-5 and compared to the commercial gel Emdogain^®. Alizarin Red was used to determine the periodontal ligament and cementoblasts cell mineralization. The inflammatory profile of these two cells was also quantified using ELISA (vascular endothelial growth factor A, tumor necrosis factor α, and interleukin 11) mediators. ADP-5 enhanced cell proliferation and remineralization; the 100 µg/mL concentration was more efficient than 50 and 200 µg/mL. The ADP-5 experimental hydrogel exhibited equivalent good biological behavior compared to Emdogain^® in terms of cell colonization, mineralization, and inflammatory profile. These findings revealed relevant insights regarding the ADP-5 biological behavior. From a clinical perspective, these outcomes could instigate the development of novel functionalized scaffold for periodontal regeneration.

Characterization of a bioscaffold containing polysaccharide acemannan and native collagen for pulp tissue regeneration

Dental pulp regeneration exploits tissue engineering concepts using stem cells/scaffolds/growth-factors. Extracted collagen is commonly used as a biomaterial-scaffold due to its biocompatibility/biodegradability and mimics the natural extracellular matrix. Adding biomolecules into a collagen-scaffold enhanced pulp regeneration. Acemannan, β-(1-4)-acetylated-polymannose, is a polysaccharide extracted from aloe vera. Acemannan is a regenerative biomaterial. Therefore, acemannan could be a biomolecule in a collagen-scaffold. Here, acemannan and native collagen were obtained and characterized. The AceCol-scaffold's physical properties were investigated using FTIR, SEM, contact angle, swelling, pore size, porosity, compressive modulus, and degradation assays. The AceCol-scaffold's biocompatibility, growth factor secretion, osteogenic protein expression, and calcification were evaluated in vitro. The AceCol-scaffolds demonstrated higher hydrophilicity, swelling, porosity, and larger pore size than the collagen scaffolds (p < 0.05). Better cell-cell and cell-scaffold adhesion, and dentin extracellular matrix protein (BSP/OPN/DSPP) expression were observed in the AceCol-scaffold, however, DSPP expression was not detected in the collagen group. Significantly increased cellular proliferation, VEGF and BMP2 expression, and mineralization were detected in the AceCol-scaffold compared with the collagen-scaffold (p < 0.05). Computer simulation revealed that acemannan's 3D structure changes to bind with collagen. In conclusion, the AceCol-scaffold synergistically provides better physical and biological properties than collagen. The AceCol-scaffold is a promising material for tissue regeneration.

Dentin regeneration based on tooth tissue engineering: A review

Missing or damaged teeth due to caries, genetic disorders, oral cancer, or infection may contribute to physical and mental impairment that reduces the quality of life. Despite major progress in dental tissue repair and those replacing missing teeth with prostheses, clinical treatments are not yet entirely satisfactory, as they do not regenerate tissues with natural teeth features. Therefore, much of the focus has centered on tissue engineering (TE) based on dental stem/progenitor cells to create bioengineered dental tissues. Many in vitro and in vivo studies have shown the use of cells in regenerating sections of a tooth or a whole tooth. Tooth tissue engineering (TTE), as a promising method for dental tissue regeneration, can form durable biological substitutes for soft and mineralized dental tissues. The cell-based TE approach, which directly seeds cells and bioactive components onto the biodegradable scaffolds, is currently the most potential method. Three essential components of this strategy are cells, scaffolds, and growth factors (GFs). This study investigates dentin regeneration after an injury such as caries using TE and stem/progenitor cell-based strategies. We begin by discussing about the biological structure of a dentin and dentinogenesis. The engineering of teeth requires knowledge of the processes that underlie the growth of an organ or tissue. Then, the three fundamental requirements for dentin regeneration, namely cell sources, GFs, and scaffolds are covered in the current study, which may ultimately lead to new insights in this field.

Synthetic electrospun nanofibers as a supportive matrix in osteogenic differentiation of induced pluripotent stem cells

Continuous remodeling is not able to repair large bone defects. Bone tissue engineering is aimed to repair these defects by creating bone grafts. To do this, several technologies and biomaterials have been employed to fabricate an in vivo-like supportive matrix. Electrospinning is a versatile technique to fabricate porous matrices with interconnected pores and high surface area, replicating in vivo microenvironment. Electrospun scaffolds have been used in a large number of studies to provide a matrix for bone regeneration and osteogenic differentiation of stem cells such as induced pluripotent stem cells (iPSCs). Electrospinning uses both natural and synthetic polymers, either alone or in combination, to fabricate scaffolds. Among them, synthetic polymers have had a great promise in bone regeneration and repair. They allow the fabrication of biocompatible and biodegradable scaffolds with high mechanical properties, suitable for bone engineering. Furthermore, several attempts have done to increase the osteogenic properties of these scaffolds. This paper reviewed the potential of synthetic electrospun scaffolds in osteogenic differentiation of iPSCs. In addition, the approaches to improve the osteogenic differentiation of these scaffolds are addressed.

In Silico Analysis of Glycosaminoglycan-Acemannan as a Scaffold Material on Alveolar Bone Healing

OBJECTIVE

 This study aimed to analyze interaction between glycosaminoglycan-acemannan as a scaffold material and toll-like receptor-2 (TLR-2) receptor, which predicted the osteogenesis potency on alveolar bone healing (in silico analysis).

MATERIALS AND METHODS

 Docking interaction between glycosaminoglycan-acemannan and TLR-2 receptor using the Molegro Virtual Docker (MVD) program. The compounds of glycosaminoglycan-acemannan and TLR-2 receptor with the structure in the form of two- and three-dimensional images were analyzed, as well as the most stable structure. It was observed the interaction of the ligand on the cavity of the TLR-2 receptor structure. The energy required for the ligand and receptor interaction (Moldock score) was calculated with MPD program.

RESULTS

 The chemical structure shows that glycosaminoglycan-acemannan is capable binding to the TLR-2 receptor with hydrogen bonds and strong steric interaction. The docking results were detected for five cavities where the compound binds to the TLR-2 receptor. The Moldock score of the ligand on the CAS-LYS-LEU-ARG-LYS-ILE-MSE[A] ligand was -95,58 Kcal/mol, that of acemannan was -91,96 Kcal/mol, and for glycosaminoglycan -61,14 Kcal/mol.

CONCLUSION

 The compound of glycosaminoglycan-acemannan as a scaffold material is able to bind with a TLR-2 target receptor, which predicted osteogenesis activity on alveolar bone healing supported by in silico analysis.

Phytochemistry and Biological Activity of Medicinal Plants in Wound Healing: An Overview of Current Research

Wound healing is a complicated process, and the effective management of wounds is a major challenge. Natural herbal remedies have now become fundamental for the management of skin disorders and the treatment of skin infections due to the side effects of modern medicine and lower price for herbal products. The aim of the present study is to summarize the most recent in vitro, in vivo, and clinical studies on major herbal preparations, their phytochemical constituents, and new formulations for wound management. Research reveals that several herbal medicaments have marked activity in the management of wounds and that this activity is ascribed to flavonoids, alkaloids, saponins, and phenolic compounds. These phytochemicals can act at different stages of the process by means of various mechanisms, including anti-inflammatory, antimicrobial, antioxidant, collagen synthesis stimulating, cell proliferation, and angiogenic effects. The application of natural compounds using nanotechnology systems may provide significant improvement in the efficacy of wound treatments. Increasing the clinical use of these therapies would require safety assessment in clinical trials.

A Review of In Vivo and Clinical Studies Applying Scaffolds and Cell Sheet Technology for Periodontal Ligament Regeneration

Different approaches to develop engineered scaffolds for periodontal tissues regeneration have been proposed. In this review, innovations in stem cell technology and scaffolds engineering focused primarily on Periodontal Ligament (PDL) regeneration are discussed and analyzed based on results from pre-clinical in vivo studies and clinical trials. Most of those developments include the use of polymeric materials with different patterning and surface nanotopography and printing of complex and sophisticated multiphasic composite scaffolds with different compartments to accomodate for the different periodontal tissues' architecture. Despite the increased effort in producing these scaffolds and their undoubtable efficiency to guide and support tissue regeneration, appropriate source of cells is also needed to provide new tissue formation and various biological and mechanochemical cues from the Extraccellular Matrix (ECM) to provide biophysical stimuli for cell growth and differentiation. Cell sheet engineering is a novel promising technique that allows obtaining cells in a sheet format while preserving ECM components. The right combination of those factors has not been discovered yet and efforts are still needed to ameliorate regenerative outcomes towards the functional organisation of the developed tissues.

A Review of Tissue Engineering for Periodontal Tissue Regeneration

Periodontal disease is one of the most common diagnoses in small animal veterinary medicine. This infectious disease of the periodontium is characterized by the inflammation and destruction of the supporting structures of teeth, including periodontal ligament, cementum, and alveolar bone. Traditional periodontal repair techniques make use of open flap debridement, application of graft materials, and membranes to prevent epithelial downgrowth and formation of a long junctional epithelium, which inhibits regeneration and true healing. These techniques have variable efficacy and are made more challenging in veterinary patients due to the cost of treatment for clients, need for anesthesia for surgery and reevaluation, and difficulty in performing necessary diligent home care to maintain oral health. Tissue engineering focuses on methods to regenerate the periodontal apparatus and not simply to repair the tissue, with the possibility of restoring normal physiological functions and health to a previously diseased site. This paper examines tissue engineering applications in periodontal disease by discussing experimental studies that focus on dogs and other animal species where it could potentially be applied in veterinary medicine. The main areas of focus of tissue engineering are discussed, including scaffolds, signaling molecules, stem cells, and gene therapy. To date, although outcomes can still be unpredictable, tissue engineering has been proven to successfully regenerate lost periodontal tissues and this new possibility for treating veterinary patients is discussed.

Efficacy of biocompatible trilayers nanofibrous scaffold with/without allogeneic adipose-derived stem cells on class II furcation defects of dogs' model

OBJECTIVE

This study aimed to evaluate the regenerative capacity of a newly-developed polycaprolactone (PCL)-based nanofibrous composite scaffold either alone or in combination with adipose-derived mesenchymal stem cells (ADSCs) as a treatment modality for class II furcation defects.

MATERIALS AND METHODS

After ADSCs isolation and scaffold characterization, the mandibular premolars of adult male mongrel dogs were selected and randomly assigned into three equal groups. In group I, class II furcation defects were surgically induced to the inter-radicular bone. While class II furcation defects of group II were induced as in group I. In addition, the defects were filled with the prefabricated scaffold. Moreover, class II furcation defects of group III were induced as in group II and instead the defects were filled with the prefabricated scaffold seeded with ADSCs. The dogs were sacrificed at 30 days or at 60 days. Periodontal wound healing/regeneration was evaluated by radiological examination using cone beam computed tomography and histologically using ordinary, histochemical, and immunohistochemical staining.

RESULTS

In the two examination periods, group II defects compared to group I, and group III compared to the other groups showed a decrease in defect dimensions radiographically. Histologically, histochemically, and immunohistochemically, they significantly demonstrated better periodontal wound healing/regeneration, predominant collagen type I of newly formed bone and periodontal ligament with a significant increase in the immunoreactivity of vascular endothelial growth factor and osteopontin.

CONCLUSIONS

The newly fabricated nanofibrous scaffold has enhanced periodontal wound healing/regeneration of class II furcation defects with further enhancement achieved when ADSCs seeded onto the scaffold before implantation.

CLINICAL RELEVANCE

The implementation of our newly-developed PCL-based nanofibrous composite scaffolds in class II furcation defect either alone or in conjunction with ADSCs can be considered as a suitable treatment modality to allow periodontal tissues regeneration.

The effect of acemannan in implant placement with simultaneous guided bone regeneration in the aesthetic zone: a randomized controlled trial

Acemannan, a linear polysaccharide produced by Aloe vera, has been shown to have important biological effects promoting wound healing and tissue regeneration. The aim of this randomized clinical trial was to investigate the impact of acemannan in guided bone regeneration (GBR) with simultaneous implant placement. Twenty patients were randomly allocated to a test group (deproteinized bovine bone with particulate acemannan (mean size 32.45 μm)) and a control group (deproteinized bovine bone only). Twenty implants were placed with simultaneous GBR. Radiographic measurements were conducted on cone beam computed tomography (CBCT) scans immediately post-surgery and at 3 and 6 months. Vertical and horizontal dimensions of the buccal bone were measured at the implant platform (0) and at points 2, 4, 6, and 8 mm apically. The dimensional reduction of vertical and horizontal buccal bone was significantly smaller in the test group at 3 months postoperative (P < 0.05) at every position measured (0, 2, 4, 6, 8 mm), but the difference was not statistically significant at 6 months. Acemannan was found to be a safe and predictable biomaterial for GBR, which resulted in enhanced dimensional stability of the regenerated tissue at 3 months. However, these results were not replicated at 6 months. Further studies are required to document the long-term efficacy and potential of acemannan use as a supplement in bone regeneration.

Effect of Complementary Medicine on Pain Relief and Wound Healing after Cesarean Section: A Systematic Review

Objectives

Cesarean sections are one of the common surgical procedures around the world. Management of cesarean section side effects, including pain, hematoma, delayed wound healing, is of particular importance in maintaining maternal health and ability to care for the baby. The tendency to use complementary medicine strategies is on the rise because of the easy treatment with low side effects. The purpose of this study was to systematically review the efficacy and safety of clinical trials performed in Iran and worldwide on the effect of complementary medicine on pain relief and wound healing after cesarean section.

Methods

PRISMA checklist was followed to prepare the report of this systematic review. The search process was carried out on databases on databases of Magiran, SID, Iran Medex, Scopus, Pub Med, Science direct, Medline and Cochrane library using keywords of cesarean, pain, wound healing, Herbal medicine, acupressure, massage, complementary medicine and their Persian equivalent and all possible combinations, from inception until February 2020. We used the Jadad scale to assess the quality of the searched articles. According to the Jadad scale, the articles with a score of at least 3 were included in the study.

Results

Finally, 28 clinical trials (with a sample size of 3,245) scored at least 3 on the Jadad scale were included into the analysis. This article reviewed 13 articles on medicinal herbs, 4 articles on massage, 1 article on reflexology, 2 articles on acupressure.

Conclusion

According to the present review, the use of medicinal herbs was the most common method of complementary medicine in pain relief and wound healing after cesarean section.

Natural medicine delivery from biomedical devices to treat bone disorders: A review

With an increasing life expectancy and aging population, orthopedic defects and bone graft surgeries are increasing in global prevalence. Research to date has advanced the understanding of bone biology and defect repair mechanism, leading to a marked success in the development of synthetic bone substitutes. Yet, the quest for functionalized bone grafts prompted the researchers to find a viable alternative that regulates cellular activity and supports bone regeneration and healing process without causing serious side-effects. Recently, researchers have introduced natural medicinal compounds (NMCs) in bone scaffold that enables them to release at a desirable rate, maintains a sustained release allowing sufficient time for tissue in-growth, and guides bone regeneration process with minimized risk of tissue toxicity. According to World Health Organization (WHO), NMCs are gaining popularity in western countries for the last two decades and are being used by 80% of the population worldwide. Compared to synthetic drugs, NMCs have a broader range of safety window and thus suitable for prolonged localized delivery for bone regeneration. There is limited literature focusing on the integration of bone grafts and natural medicines that provides detailed scientific evidences on NMCs, their toxic limits and particular application in bone tissue engineering, which could guide the researchers to develop functionalized implants for various bone disorders. This review will discuss the emerging trend of NMC delivery from bone grafts, including 3D-printed structures and surface-modified implants, highlighting the significance and potential of NMCs for bone health, guiding future paths toward the development of an ideal bone tissue engineering scaffold. STATEMENT OF SIGNIFICANCE: To date, additive manufacturing technology provids us with many advanced patient specific or defect specific bone constructs exhibiting three-dimensional, well-defined microstructure with interconnected porous networks for defect-repair applications. However, an ideal scaffold should also be able to supply biological signals that actively guide tissue regeneration while simultaneously preventing post-implantation complications. Natural biomolecules are gaining popularity in tissue engineering since they possess a safer, effective approach compared to synthetic drugs. The integration of bone scaffolds and natural biomolecules exploits the advantages of customized, multi-functional bone implants to provide localized delivery of biochemical signals in a controlled manner. This review presents an overview of bone scaffolds as delivery systems for natural biomolecules, which may provide prominent advancement in bone development and improve defect-healing caused by various musculoskeletal disorders.

Acemannan-induced tooth socket healing: A 12-month randomized controlled trial

Background/purpose

Natural compounds have become alternatives for bone regeneration. Acemannan, the main polysaccharide extracted from Aloe vera, has been demonstrated as a promising osteoinductive material in vitro and in vivo. This clinical study investigated the effect of acemannan on tooth socket healing.

Materials and methods

Thirty-five otherwise healthy patients, 18–25 years old and diagnosed with horizontal or vertical partial impaction of the lower third molars, were enrolled in this randomized controlled trial. After removing the teeth, the sockets randomly received one of the following treatments: spontaneous blood-clotting (control), 20 mg acemannan sponge, or 50 mg acemannan sponge. Cone-beam computed tomography of the mandible was performed immediately (baseline), and at 3-, 6-, and 12-months postoperatively; the data were analyzed using the OsiriX MD program. Bone healing in the socket was determined measuring the socket volume. One-way ANOVA was used to analyze the differences within each group and between groups.

Results

Thirty-five patients with 43 partially impacted lower third molars participated in this study. No patients exhibited alveolar osteitis or secondary infection. Compared with baseline, all groups showed significant reduction in socket volume at all observation time-points (p < 0.05). The 50 mg acemannan group had a significantly greater reduction in socket volume compared with the control at all postoperative time-points (p < 0.05). The 20 mg group had a significantly greater reduction in socket volume compared with the control at 3-months postoperatively (p < 0.05).

Conclusion

We conclude that acemannan increases bone healing at 3-, 6-, and 12-months after removal of partially impacted mandibular third molars.

Acemannan induces rapid early osseous defect healing after apical surgery: A 12-month follow-up of a randomized controlled trial

Background/purpose

Acemannan is an osteoinductive material. This study's objective was to compare the outcomes of bone defect healing using 3-dimensional images after apical surgery with or without adding acemannan sponges.

Materials and methods

Twenty-two anterior teeth from 9 males and 13 females requiring apical surgery were included in this randomized controlled trial. Post-surgery, the bone defects were randomly divided into three groups: blood clot control, 5-, or 10-mg acemannan sponge groups. CBCT scans were taken immediately (baseline), 3-, 6-, and 12-month post-surgery. Sagittal serial sections (1 mm thick slices parallel to the long axis of the tooth) of the defect image were created. The defect boundary was located and the total bone defect volume (BDV) was calculated from the sum of the volume of the serial defect sections. The bone healing was assessed by the percentage of total bone defect volume reduction (%ΔBDV). The paired t-test and one-way ANOVA were used to analyze the differences within each group and between groups, respectively.

Results

The baseline mean BDV of the control, 5-, and 10-mg acemannan groups were not significantly different (p > 0.05). After treatment, the mean BDV for each group was reduced in a time-dependent manner. Compared with the control group, the 5- and 10-mg acemannan groups had a significantly greater %ΔBDV (approximately 2- and 1.89-fold) at 3-months post-surgery, respectively (p < 0.05). However, at the 6- and 12- month follow-up, the %ΔBDV was not significantly different between the groups.

Conclusion

These data suggest acemannan enhanced early bone healing after apical surgery.

Acemannan Used as an Implantable Biomaterial for Vital Pulp Therapy of Immature Permanent Teeth Induced Continued Root Formation

Direct pulp-capping, a vital pulp therapy, is used to protect and preserve pulp vitality by applying a biomaterial on the pulp exposure site. Acemannan, a polysaccharide extracted from Aloe vera, induces osteodentin-bridge formation to cover the exposure site in vivo. We evaluated the effect of acemannan sponges on partial pulpotomized permanent teeth with caries or accident-induced pulp exposure (n = 50). After removing infected dentin and inflamed pulp tissue, the teeth were randomly divided into acemannan or control (mineral trioxide aggregate (MTA) groups (n = 25). The teeth were examined immediately after treatment (baseline) and at 6- and 12-month follow-ups for clinical and cone beam computed tomography (CBCT) examination. The three-dimensional tooth length and root apex area were simulated to determine treatment success. We found that the overall success rate in the acemannan and MTA groups from baseline to 12-month follow-up was 90.91% and 95.65%, respectively, with no significant difference between the two groups (p > 0.05). In the success teeth in both groups, the root length increased, and the apex area significantly decreased (p < 0.05), indicating continued root formation. Our results suggest that acemannan is a promising low-cost biomaterial for partial pulpotomy treatment for immature permanent teeth requiring vital pulp therapy.

Natural Medicinal Compounds in Bone Tissue Engineering

Recent advances in 3D printing have provided unprecedented opportunities in bone tissue engineering applications for producing a variety of complex patient-specific implants for the treatment of critical-sized bone defects. Natural medicinal compounds (NMCs) with osteogenic potential can be incorporated into these 3D-printed parts to improve bone formation and therefore enhance implant performance. Using NMCs to treat bone-related disorders may prove to be a healthy preventive choice as they are considered safe, have lesser or no side effects, and are more suitable for prolonged use than synthetic drugs. In this review paper, the current challenges of bone tissue engineering are addressed briefly, highlighting the immense potential of NMCs integrated within tissue engineering scaffolds for orthopedic and dental applications.

Evaluation of hydrophilic gel made from Acemannan and Moringa oleifera in enhancing osseointegration of dental implants. A preliminary study in rabbits

BACKGROUND

Hydrophilic implant surface has gained increasing interest as a factor to stimulate osseointegration.

PURPOSE

The study was done to formulate hydrophilic gel to be applied on to the dental implant surface, to enhance bone to implant contact (BIC).

MATERIALS AND METHODS

In first part of study, Acemannan and Moringa oleifera hydro gel formulated in different proportions were coated on the titanium disk and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay was done to evaluate cell viability.Cytotoxicity of aqueous extracts of two plants were tested against UMR106 cells. In second part of study, the prototype titanium implants were placed in tibia and femur of 8 male rabbits. Hydrophilic gel formulated from Acemannan and Moringa oleifera were coated on the study groups of implants. Histomorphometric analysis was carried out of the enbloc sections specimens. Student's unpaired t-test was used to compare mean values between the two groups.

RESULTS

The alkaline phosphatase assay showed least cell inhibition for Acemannan and Moringa oleifera (2:1) as 4.45% and osteoblastic differentiation as 0.328 at 540 nm. Titamium disc coated with hydrogel of Acemannan and Moringa oliefera and seeded with Human MSC shows increased proliferation of osteoblast cells.Compare to study group implants, control group showed no new bone formation.

CONCLUSIONS

Hydrophilic implant surface showed new bone formation with increased bone to implant contact.There was absent of degenerative changes, necrotic changes, fibrosis, and inflammation at the new BIC.

Fibre guiding scaffolds for periodontal tissue engineering

The periodontium is a highly hierarchically organized organ composed of gingiva, alveolar bone, periodontal ligament and cementum. Periodontitis leads to the destruction of hard and soft tissues ultimately leading to a loss of the teeth supporting apparatus. Current treatments are capable of limiting the disease progression; however, true regeneration, characterized by perpendicularly oriented periodontal ligament fibre attachment to cementum on the root surface remains challenging. Tissue engineering approaches have been developed to enhance regeneration via micro-engineered topographical features, purposely designed to guide the insertion of the regenerated ligament to the root surface. This review reports on the recent advancements in scaffold manufacturing methodologies for generating fibre guiding properties and provides a critical insight in the current limitations of these techniques for the formation of functional periodontal attachment.

Acemannan Induced Bone Regeneration in Lateral Sinus Augmentation Based on Cone Beam Computed Tomographic and Histopathological Evaluation

Acemannan, the major polysaccharide extracted from Aloe vera, is biomaterial that has demonstrated osteoinductive effects in vitro and in vivo. However, the effect of acemannan sponges on bone formation in open-type sinus augmentation has not evaluated. Here, we report a case study using radiographic and histological analyses to investigate the effect of acemannan on bone formation after lateral sinus lift surgery. The case was a 57-year-old female patient with an atrophic left posterior maxilla who underwent lateral sinus lift using an acemannan sponge using the two-stage procedure. In the first stage, an acemannan sponge was inserted through the bony window and placed between the antral floor and the elevated sinus membrane. Cone beam computed tomography (CBCT) images were taken immediately as baseline and 6-month postoperation for evaluation. A bone core specimen was also obtained for histological examination at the time of implant placement. The histological results revealed new bone formation, and the CBCT images demonstrated increased alveolar bone height at 6-month postoperation. Our findings suggest that an acemannan sponge could be a biomaterial for inducing bone formation in sinus lift surgery.

Indirect Sinus Augmentation With and Without the Addition of a Biomaterial: A Randomized Controlled Clinical Trial

PURPOSE

The aim of this study was to compare the results of indirect sinus augmentation with and without the addition of a biomaterial.

MATERIALS AND METHODS

Thirty patients aged 40 to 60 years participated in this randomized controlled clinical trial. After closed sinus lift operation, patients were randomly and equally divided into blood clot control and acemannan sponge graft groups. Simultaneous implant placement was then performed. Cone beam computed tomography was performed immediately and at 3 and 6 months postoperation. Bone formation was evaluated by the radiographic endo-sinus bone gain percentage around the implant.

RESULTS

Compared with the control group, the acemannan-treated group had a significantly greater radiographic endo-sinus bone gain percentage of approximately 2.4- and 2-fold at 3 and 6 months postsurgery, respectively (P < 0.05).

CONCLUSION

The addition of a biomaterial (Acemannan) with indirect sinus augmentation and simultaneous implant placement significantly enhances bone formation at 3 and 6 months postsurgery.

Effects of Aloe Vera Gel Extract in Doped Hydroxyapatite-Coated Titanium Implants on in Vivo and in Vitro Biological Properties

Hydroxyapatite-coated titanium alloys have been a popular choice as bone implants for load-bearing applications for the compositional similarity of hydroxyapatite to natural bone. The limited osteoinductive properties exhibited by the hydroxyapatite (HA) coatings have led to the incorporation of growth factor or dopants for improved osseointegration. This study aims to investigate the effects of a naturally occurring aloe vera gel extract, acemannan, in doped hydroxyapatite coatings on the in vitro osteoblast cell viability and in vivo new bone formation in a rat distal femur model. Silver oxide and silica-doped hydroxyapatite coatings were developed by the induction plasma spray coating method on Ti alloys to introduce antibacterial properties along with induction of angiogenic properties, respectively. The doped coating was further consecutively dip coated with acemannan to analyze its effects on the in vivo early stage osseointegration and chitosan to control the burst release of the acemannan from the calcium phosphate matrix. The results show controlled release of acemannan from the chitosan coatings, with enhanced osteoblast cell viability by the incorporation of acemannan in vitro. Improved osseointegration with a seamless implant interface and improved new bone formation was noted by the acemannan and chitosan coating in vivo, 5 weeks after implantation. Our results demonstrate the efficacy of a combination of natural medicine and naturally occurring polymer in a doped hydroxyapatite-coated titanium implant on the bone tissue regeneration for load-bearing orthopedic applications.

Influence of Micropatterning on Human Periodontal Ligament Cells' Behavior

The periodontal ligament (PDL) is highly ordered connective tissue located between the alveolar bone and cementum. An aligned and organized architecture is required for its physiological function. We applied micropatterning technology to arrange PDL cells in 10- or 20-μm-wide extracellular protein patterns. Cell and nuclear morphology, cytoskeleton, proliferation, differentiation, and matrix metalloproteinase system expression were investigated. Micropatterning clearly elongated PDL cells with a low cell-shape index and low spreading area. The nucleus was also elongated as nuclear height increased, but the nuclear volume remained intact. The cytoskeleton was rearranged to form prominent bundles at cells' peripheral regions. Moreover, proliferation was promoted by 10- and 20-μm micropatterning. Osteogenesis and adipogenesis were each inhibited, but micropatterning increased PDL cells' stem cell markers. β-catenin was expelled to cytoplasm. YAP/TAZ nuclear localization and activity both decreased, which might indicate their role in micropatterning-regulated differentiation. Collagen Ι expression increased in micropatterned groups. It might be due to the decreased expression of matrix metalloproteinase-1, 2 and the tissue inhibitor of metalloproteinase-1 gene expression elevation in micropatterned groups. The findings of this study provide insight into the effects of a micropatterned surface on PDL cell behavior and may be applicable in periodontal tissue regeneration.

Histologic evidence of periodontal regeneration in furcation defects: a systematic review

OBJECTIVE

To systematically review the available histologic evidence on periodontal regeneration in class II and III furcations in animals and humans.

MATERIALS AND METHODS

A protocol including all aspects of a systematic review methodology was developed including definition of the focused question, defined search strategy, study inclusion criteria, determination of outcome measures, screening methods, data extraction and analysis, and data synthesis. The focused question was defined as follows: "What is the regenerative effect obtained by using or not several biomaterials as adjuncts to open flap surgery in the treatment of periodontal furcation defects as evaluated in animal and human histological studies?"

SEARCH STRATEGY

Using the MEDLINE database, the literature was searched for articles published up to and including September 2018: combinations of several search terms were applied to identify appropriate studies. Reference lists of review articles and of the included articles in the present review were screened. A hand search of the most important dental journals was also performed.

CRITERIA FOR STUDY SELECTION AND INCLUSION

Only articles published in English describing animal and human histological studies evaluating the effect of surgical treatment, with or without the adjunctive use of potentially regenerative materials (i.e., barrier membranes, grafting materials, growth factors/proteins, and combinations thereof) for the treatment of periodontal furcation defects were considered. Only studies reporting a minimum of 8 weeks healing following reconstructive surgery were included. The primary outcome variable was formation of periodontal supporting tissues [e.g., periodontal ligament, root cementum, and alveolar bone, given as linear measurements (in mm) or as a percentage of the instrumented root length (%)] following surgical treatment with or without regenerative materials, as determined histologically/histomorphometrically. Healing type and defect resolution (i.e., complete regeneration, long junctional epithelium, connective tissue attachment, connective tissue adhesion, or osseous repair) were also recorded.

RESULTS

In animals, periodontal regeneration was reported in class II and III defects with open flap debridement alone or combined with various types of bone grafts/bone substitues, biological factors, guided tissue regeneration, and different combinations thereof. The use of biological factors and combination approaches provided the best outcomes for class II defects whereas in class III defects, the combination approaches seem to offer the highest regenerative outcomes. In human class II furcations, the best outcomes were obtained with DFDBA combined with rhPDGF-BB and with GTR. In class III furcations, evidence from two case reports indicated very limited to no periodontal regeneration.

CONCLUSIONS

Within their limits, the present results suggest that (a) in animals, complete periodontal regeneration has been demonstrated in class II and class III furcation defects, and (b) in humans, the evidence for substantial periodontal regeneration is limited to class II furcations.

CLINICAL RELEVANCE

At present, regenerative periodontal surgery represents a valuable treatment option only for human class II furcation defects but not for class III furcations.

Extraction, Purification, Structural Characteristics, Biological Activities and Pharmacological Applications of Acemannan, a Polysaccharide from Aloe vera: A Review

Aloe vera is a medicinal plant species of the genus Aloe with a long history of usage around the world. Acemannan, considered one of the main bioactive polysaccharides of Aloe vera, possesses immunoregulation, anti-cancer, anti-oxidation, wound healing and bone proliferation promotion, neuroprotection, and intestinal health promotion activities, among others. In this review, recent advancements in the extraction, purification, structural characteristics and biological activities of acemannan from Aloe vera were summarized. Among these advancements, the structural characteristics of purified polysaccharides were reviewed in detail. Meanwhile, the biological activities of acemannan from Aloe vera determined by in vivo, in vitro and clinical experiments are summarized, and possible mechanisms of these bioactivities were discussed. Moreover, the latest research progress on the use of acemannan in dentistry and wound healing was also summarized in details. The structure-activity relationships of acemannan and its medical applications were discussed. Finally, new perspectives for future research work on acemannan were proposed. In conclusion, this review summarizes the extraction, purification, structural characteristics, biological activities and pharmacological applications of acemannan, and provides information for the industrial production and possible applications in dentistry and wound healing in the future.

The influence of Aloe vera with mesenchymal stem cells from dental pulp on bone regeneration: characterization and treatment of non-critical defects of the tibia in rats

OBJECTIVE

This study aimed to evaluate the inflammatory effect and bone formation in sterile surgical failures after implantation of a collagen sponge with mesenchymal stem cells from human dental pulp (hDPSCs) and Aloe vera.

MATERIAL AND METHODS

Rattus norvegicus (n=75) were divided into five experimental groups according to treatment: G1) control (blood clot); G2) Hemospon®; G3) Hemospon® in a culture medium enriched with 8% Aloe vera; G4) Hemospon® in a culture medium containing hDPSCs and G5) Hemospon® in a culture medium enriched with 8% Aloe vera and hDPSCs. On days 7, 15 and 30, the animals were euthanized, and the tibia was dissected for histological, immunohistochemistry and immunofluorescence analyses. The results were analyzed using nonparametric Kruskal-Wallis test and Dunn's post-test.

RESULTS

On days 7 and 15, the groups with Aloe vera had less average acute inflammatory infiltrate compared to the control group and the group with Hemospon® (p<0.05). No statistically significant difference was found between the groups regarding bone formation at the three experimental points in time. Osteopontin expression corroborated the intensity of bone formation. Fluorescence microscopy revealed positive labeling with Q-Tracker® in hDPSCs before transplantation and tissue repair.

CONCLUSION

The results suggest that the combination of Hemospon®, Aloe vera and hDPSCs is a form of clinical treatment for the repair of non-critical bone defects that reduces the inflammatory cascade's effects.

Plant-Derived Bioactives in Oral Mucosal Lesions: A Key Emphasis to Curcumin, Lycopene, Chamomile, Aloe vera, Green Tea and Coffee Properties

Oral mucosal lesions have many etiologies, including viral or bacterial infections, local trauma or irritation, systemic disorders, and even excessive alcohol and tobacco consumption. Folk knowledge on medicinal plants and phytochemicals in the treatment of oral mucosal lesions has gained special attention among the scientific community. Thus, this review aims to provide a brief overview on the traditional knowledge of plants in the treatment of oral mucosal lesions. This review was carried out consulting reports between 2008 and 2018 of PubMed (Medline), Web of Science, Embase, Scopus, Cochrane Database, Science Direct, and Google Scholar. The chosen keywords were plant, phytochemical, oral mucosa, leukoplakia, oral lichen planus and oral health. A special emphasis was given to certain plants (e.g., chamomile, Aloe vera, green tea, and coffea) and plant-derived bioactives (e.g., curcumin, lycopene) with anti-oral mucosal lesion activity. Finally, preclinical (in vitro and in vivo) and clinical studies examining both the safety and efficacy of medicinal plants and their derived phytochemicals were also carefully addressed.

Photocrosslinked acemannan-based 3D matrices for in vitro cell culture

Photocrosslinking on acemannan is proposed as a green approach for the production of high added-value acemannan structures, enabling its biomedical exploitation.

Tissue Engineered Constructs for Periodontal Regeneration: Current Status and Future Perspectives

The periodontium, consisting of gingiva, periodontal ligament, cementum, and alveolar bone, is a hierarchically organized tissue whose primary role is to provide physical and mechanical support to the teeth. Severe cases of periodontitis, an inflammatory condition initiated by an oral bacterial biofilm, can lead to significant destruction of soft and hard tissues of the periodontium and result in compromised dental function and aesthetics. Although current treatment approaches can limit the progression of the disease by controlling the inflammatory aspect, complete periodontal regeneration cannot be predictably achieved. Various tissue engineering approaches are investigated for their ability to control the critical temporo-spatial wound healing events that are essential for achieving periodontal regeneration. This paper reviews recent progress in the field of periodontal tissue engineering with an emphasis on advanced 3D multiphasic tissue engineering constructs (TECs) and provides a critical analysis of their regenerative potential and limitations. The review also elaborates on the future of periodontal tissue engineering, including scaffold customization for individual periodontal defects, TEC's functionalization strategies for imparting enhanced bioactivity, periodontal ligament fiber guidance, and the utilization of chair-side regenerative solutions that can facilitate clinical translation.

Plants and Their Bioactive Constituents in Mesenchymal Stem Cell-Based Periodontal Regeneration: A Novel Prospective

Periodontitis is a common chronic inflammatory disease, which causes the destruction of both the soft and mineralized tissues. However, current treatments such as bone graft materials, barrier membranes, and protein products all have difficulties in regenerating the complete periodontal tissue structure. Stem cell-based tissue engineering has now emerged as one of the most effective treatments for the patients suffering from periodontal diseases. Plants not only can be substrates for life processes, but also contain hormones or functional molecules. Numbers of preclinical studies have revealed that products from plant can be successfully applied in modulating proliferation and differentiation of human mesenchymal stem cells. Plant-derived substances can induce stem cells osteogenic differentiation, and they also possess angiogenic potency. Furthermore, in the field of tissue engineering, plant-derived compounds or plant extracts can be incorporated with biomaterials or utilized as biomaterials for cell transplantation. So it is speculated that botanical products may become a new perspective in stem cell-based periodontal regeneration. However, the lack of achieving predict clinical efficacy and quality control has been the major impediment to its extensive application. This review gives an overview of the prospect of applying different plant-derived substances in various human mesenchymal stem cells-based periodontal regeneration.

Acemannan increased bone surface, bone volume, and bone density in a calvarial defect model in skeletally-mature rats

Background/purpose

Acemannan, a β-(1-4)-acetylated polymannose extracted from Aloe vera gel, has been proposed as biomaterial for bone regeneration. The aim of this study was to investigate the effect of acemannan in calvarial defect healing.

Materials and methods

Acemannan was processed to freeze-dried sponge form and disinfected by UV irradiation. Thirty-five female Sprague-Dawley rats were used in the in vivo study. Seven-mm diameter mid-calvarial defects were created and randomly allocated into blood clot control (C), acemannan 1 mg (A1), 2 mg (A2), 4 mg (A4), and 8 mg (A8) groups (n = 7). After four weeks, the calvarial specimens were subjected to microcomputed tomography (microCT) and histopathological analysis.

Results

MicroCT revealed a significant increase in bone surface and bone volume in the A1 and A2 groups, and tissue mineral density in the A4 and A8 groups compared with the control group (p < 0.05). Histologically, the acemannan-treated groups had denser bone matrix compared with the control group.

Conclusion

Acemannan is an effective bioactive agent for bone regeneration, enhancing bone growth as assayed in two- and three-dimensions.

One percent alendronate and aloe vera gel local host modulating agents in chronic periodontitis patients with class II furcation defects: A randomized, controlled clinical trial

AIM

Alendronate (ALN) has antiresorptive and osteostimulative properties. The major component of aloe vera (AV) gel is acemannan, which has been found to have osteogenic properties. The aim of the present study is to explore the effectiveness of 1% ALN and AV gel as an adjunct to scaling and root planing (SRP) in chronic periodontitis patients with class II furcation defects.

METHODS

Ninety volunteers were randomly assigned to three treatment groups: (a) SRP plus placebo gel; (b) SRP plus 1% ALN gel; and (c) SRP plus AV gel. Clinical and radiographic parameters were recorded at baseline and at 6 and 12 months.

RESULTS

The mean probing depth reduction and relative horizontal clinical attachment level (CAL) and relative vertical CAL gains were greater in the ALN group than in the AV and placebo groups at 6 and 12 months. Furthermore, a significantly greater mean percentage of defect depth reduction (DDR) was found in the ALN group (38.09 ± 9.53, 44.86 ± 6.29) than the AV groups (11.94 ± 15.10, 14.59 ± 25.49) at 6 and 12 months, respectively.

CONCLUSION

ALN showed significant improvement in all clinical parameters, along with greater DDR, compared to AV in the treatment of class II furcation defects as an adjunct to SRP.

Development of fish collagen/bioactive glass/chitosan composite nanofibers as a GTR/GBR membrane for inducing periodontal tissue regeneration

The development of a guided tissue or bone regeneration (GTR/GBR) membrane with excellent performance has been a major challenge in the biomedical field. The present study was designed to prepare a biomimetic electrospun fish collagen/bioactive glass/chitosan (Col/BG/CS) composite nanofiber membrane and determine its structure, mechanical property, antibacterial activity, and biological effects on human periodontal ligament cells (HPDLCs). The effects of this composite membrane on inducing periodontal tissue regeneration were evaluated using a dog class II furcation defect model. It was found that the composite membrane had a biomimetic structure with good hydrophilicity (the contact angle was 12.83 ± 3°) and a tensile strength of 13.1 ± 0.43 Mpa. Compared to the pure fish collagen membrane, the composite membrane showed some degree of antibacterial activity on Streptococcus mutans. The composite membrane not only enhanced the cell viability and osteogenic gene expression of the HPDLCs, but also promoted the expression of RUNX-2 and OPN protein. Further animal experiments confirmed that the composite membrane was able to promote bone regeneration in the furcation defect of dogs. In conclusion, a biomimetic fish Col/BG/CS composite membrane has been developed in the present study, which can induce tissue regeneration with a certain degree antibacterial activity, providing a basis for potential application as a GTR/GBR membrane.

Stimulation of Dentin Regeneration by Using Acemannan in Teeth with Lipopolysaccharide-induced Pulp Inflammation

INTRODUCTION

This study investigated the effects of acemannan, a polysaccharide from Aloe vera, on human deciduous pulp cells in vitro and the response after vital pulp therapy in dog deciduous teeth.

METHODS

Human primary dental pulpal cells were treated with acemannan in vitro and evaluated for proliferation, alkaline phosphatase activity, type I collagen, bone morphogenetic protein (BMP-2), BMP-4, vascular endothelial growth factor, and dentin sialoprotein expression and mineralization. Osteogenesis-related gene expression was analyzed by complementary DNA microarray. Pulpal inflammation was induced in dog teeth for 14 days. The inflamed pulp was removed, retaining the healthy pulp. The teeth were randomly divided into 3 treatment groups: acemannan, mineral trioxide aggregate, and formocresol. Sixty days later, the teeth were extracted and evaluated histopathologically.

RESULTS

Acemannan significantly increased pulp cell proliferation, alkaline phosphatase, type I collagen, BMP-2, BMP-4, vascular endothelial growth factor, and dentin sialoprotein expression and mineralization approximately 1.4-, 1.6-, 1.6-, 5.5-, 2.6-, 3.8-, 1.8-, and 4.8-fold, respectively, compared with control. In vivo, partial pulpotomy treatment using acemannan generated outcomes similar to mineral trioxide aggregate treatment, resulting in mineralized bridge formation with normal pulp tissue without inflammation or pulp necrosis. In contrast, the formocresol group demonstrated pulp inflammation without mineralized bridge formation.

CONCLUSIONS

Acemannan is biocompatible with the dental pulp. Furthermore, acemannan stimulated dentin regeneration in teeth with reversible pulpitis.

Acemannan increases NF-κB/DNA binding and IL-6/-8 expression by selectively binding Toll-like receptor-5 in human gingival fibroblasts

Acemannan, an acetylated polymannose from Aloe vera, has immunomodulatory effects. We investigated whether acemannan induces IL-6 and -8 expression and NF-κB/DNA binding in human gingival fibroblasts. IL-6 and -8 expression levels were assessed via RT-PCR and ELISA. The NF-κB p50/p65-DNA binding was determined. The structures of acemannan mono-pentamers and Toll-like receptor 5 (TLR5) were simulated. The binding energies between acemannan and TLR5 were identified. We found that acemannan significantly stimulated IL-6/-8 expression at both the mRNA and protein level and significantly increased p50/DNA binding. Preincubation with an anti-TLR5 neutralizing antibody abolished acemannan-induced IL-6/-8 expression and p50/DNA binding, and co-incubation of acemannan with Bay11-7082, a specific NF- κB inhibitor, abolished IL-6/-8 expression. The computer modeling indicated that monomeric/dimeric single stranded acemannan molecules interacted with the TLR5 flagellin recognition sites with a high binding affinity. We conclude that acemannan induces IL-6/-8 expression, and p50/DNA binding in gingival fibroblasts, at least partly, via a TLR5/NF-κB-dependent signaling pathway. Furthermore, acemannan selectively binds with TLR5 ectodomain flagellin recognition sites.

Effects of Hypericum perforatum on the healing of xenografts: a histomorphometric study in rabbits

The aim of this study was to investigate effects of the Hypericum perforatum (St John's Wort) on bone healing in rabbit calvarium. Ten male New Zealand rabbits each had three bicortical defects made in the calvarial bones, which were filled with xenograft, xenograft+H perforatum oil extract, and autogenous graft. Four weeks postoperatively all rabbits were killed and the bony defects examined histomorphometrically. Tissue compartments including new bone (p<0.001), marrow space (p<0.001), and residual bone grafts (p=0.014) differed significantly among groups. The volume of residual graft was significantly decreased in the xenograft/H perforatum group compared with those with xenografts alone (p=0.0147). The differences in microarchitectural variables of de novo bone formation were also significant (trabecular thickness (p<0.001), trabecular width (p<0.001), trabecular separation (p=0.001). There were no significant differences in node:terminus ratio between the xenograft/H perforatum group and the other two groups. However, the difference in node:terminus ratio between the autogenous graft and xenograft group was significant (p=0.001) Oil extracts of H perforatum improved bony healing in defects filled with bovine-derived xenografts.

Effects of Plants on Osteogenic Differentiation and Mineralization of Periodontal Ligament Cells: A Systematic Review

This systematic review aimed to evaluate the effects of plants on osteogenic differentiation and mineralization of human periodontal ligament cells. The included studies were selected using five different electronic databases. The reference list of the included studies was crosschecked, and a partial gray literature search was undertaken using Google Scholar and ProQuest. The methodology of the selected studies was evaluated using GRADE. After a two-step selection process, eight studies were identified. Six different types of plants were reported in the selected studies, which were Morinda citrifolia, Aloe vera, Fructus cnidii, Zanthoxylum schinifolium, Centella asiatica, and Epimedium species. They included five types of isolated plant components: acemannan, osthole, hesperetin, asiaticoside, and icariin. In addition, some active substances of these components were identified as polysaccharides, coumarins, flavonoids, and triterpenes. The studies demonstrated the potential effects of plants on osteogenic differentiation, cell proliferation, mineral deposition, and gene and protein expression. Four studies showed that periodontal ligament cells induce mineral deposition after plant treatment. Although there are few studies on the subject, current evidence suggests that plants are potentially useful for the treatment of periodontal diseases. However, further investigations are required to confirm the promising effect of these plants in regenerative treatments.

Incorporation of aligned PCL-PEG nanofibers into porous chitosan scaffolds improved the orientation of collagen fibers in regenerated periodontium

The periodontal ligament (PDL) is a group of highly aligned and organized connective tissue fibers that intervenes between the root surface and the alveolar bone. The unique architecture is essential for the specific physiological functionalities of periodontium. The regeneration of periodontium has been extensively studied by researchers, but very few of them pay attention to the alignment of PDL fibers as well as its functionalities. In this study, we fabricated a three-dimensional multilayered scaffold by embedding highly aligned biodegradable poly (ε-caprolactone)-poly(ethylene glycol) (PCE) copolymer electrospun nanofibrous mats into porous chitosan (CHI) to provide topographic cues and guide the oriented regeneration of periodontal tissue. In vitro, compared with random group and porous control, aligned nanofibers embedded scaffold could guide oriented arrangement and elongation of cells with promoted infiltration, viability and increased periodontal ligament-related genes expression. In vivo, aligned nanofibers embedded scaffold showed more organized arrangement of regenerated PDL nearly perpendicular against the root surface with more extensive formation of mature collagen fibers than random group and porous control. Moreover, higher expression level of periostin and more significant formation of tooth-supporting mineralized tissue were presented in the regenerated periodontium of aligned scaffold group. Incorporation of aligned PCE nanofibers into porous CHI proved to be applicable for oriented regeneration of periodontium, which might be further utilized in regeneration of a wide variety of human tissues with a specialized direction.

STATEMENT OF SIGNIFICANCE

The regeneration of periodontium has been extensively studied by researchers, but very few of them give attention to the alignment of periodontal ligament (PDL) fibers as well as its functionalities. The key issue is to provide guidance to the orientation of cells with aligned arrangement of collagen fibers perpendicular against the root surface. This study aimed to promote oriented regeneration of periodontium by structural mimicking of scaffolds. The in vitro and in vivo performances of the scaffolds were further evaluated to test the topographic-guiding and periodontium healing potentials. We also think our research may provide ideas in regeneration of a wide variety of human tissues with a specialized direction.