Alveolar bone regeneration by implantation of nacre and B-tricalcium phosphate in guinea pig

Nacre Extract from Pearl Oyster Shell Prevents D-Galactose-Induced Brain and Skin Aging

Pearl oyster shells comprise two layers, a prismatic and nacreous layer, of calcium carbonate. The nacreous layer has been used in Chinese medicine since ancient times. In this study, we investigated the effects of the extract from the nacreous layer of pearl oysters (nacre extract) on D-galactose-induced brain and skin aging. Treatment with nacre extract led to the recovery of D-galactose-induced memory impairment, as examined using the Barnes maze, novel object recognition, and Y-maze tests. A histological study showed that nacre extract suppressed D-galactose-induced neuronal cell death and the expression of B cell lymphoma 2 (Bcl-2)-associated X protein (Bax), which causes apoptosis in the hippocampus. In addition, the expression levels of brain-derived neurotrophic factor, which counteracts age-related brain dysfunction, and nicotinamide adenine dinucleotide-dependent deacetylase (sirtuin 1), which delays aging and extends lifespan, increased after nacre extract treatment. Moreover, the nacre extract showed anti-aging effects against D-galactose-induced skin aging; it suppressed D-galactose-induced wrinkle formation, decreased skin moisture, decreased epidermal thickness, and destroyed collagen arrangement associated with aging. Furthermore, the nacre extract suppressed oxidative stress associated with aging in the brain and skin by upregulating the expression of catalase and superoxide dismutase. The expression level of the cellular senescence marker p16, which is induced by oxidative stress, was elevated in the hippocampus and skin epidermal layer of D-galactose-treated mice, and it was suppressed by the administration of nacre extract. These results show that the nacre extract can suppress D-galactose-induced aging by enhancing anti-oxidant activity and suppressing p16 expression. Thus, the nacre extract may be an effective anti-aging agent.

Immuno-histologic and histomorphometric evaluation of Angelica sinensis adjunctive to ß-tricalcium phosphate in critical-sized class II furcation defects in dogs

OBJECTIVE

The study evaluates the effectiveness of Angelica sinensis (As) adjunctive to Beta-tricalcium phosphate (β-TCP) bone graft in the management of induced critical sized class II furcation defects in dogs.

MATERIAL AND METHOD

A randomized study design was conducted on the third and fourth premolars of six dogs. A total of twenty-four defects were surgically created. After reflecting a mucoperiosteal flap, twelve defects were filled with As granules mixed with β-TCP (Experimental group) while the other twelve defects were filled with β-TCP only (Control group) and both were covered by collagen membrane. At the fourth and eighth weeks, jaw segments were dissected and processed for immune-histological examination and histomorphometry analysis.

RESULTS

At four and eight weeks after treatment, experimental group showed a statistically significant increase in the height of newly formed interradicular bone (p = 0.001 and p = 0.0001 respectively), its surface area (p = 0.002 and p = 0.02 respectively), and the thickness of its trabeculae (p = 0.0001 and p = 0.001 respectively), when compared to control group. Moreover. alkaline phosphatase immunoreaction showed higher intensity in the osteoblast cells of experimental group compared to control group.

CONCLUSION

As enhances periodontal regeneration and bone-formation when used in the management of furcation defects.

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.

Preclinical safety study of nacre powder in an intraosseous sheep model

Objectives

The purpose of this preclinical study was to evaluate the safety, the local tissue effects and bone healing performance (osteoconduction, osseointegration) of nacre powder in a sheep intraosseous implantation model. This represents the first preclinical study to assess nacre safety and efficacy in supporting new bone formation in accordance with the ISO 10993 standard for biomedical devices.

Methods

The local tissue effects and the material performance were evaluated 8 weeks after implantation by qualitative macroscopic observation and qualitative as well as semiquantitative microscopic analyses of the bone sites. Histopathological characterisations were run to assess local tissue effects. In addition, microarchitectural, histomorphometric and histological characterisations were used to evaluate the effects of the implanted material.

Results

Nacre powder was shown to cause a moderate inflammatory response in the site where it was implanted compared with the sites left empty. The biomaterial implanted within the generated defects was almost entirely degraded over the investigated time span and resulted in the formation of new bone with a seamless connection with the surrounding tissue. On the contrary, in the empty defects, the formation of a thick compact band of sclerotic bone was observed by both microarchitectural and histological characterisation.

Conclusions

Nacre powder was confirmed to be a safe biomaterial for bone regeneration applications in vivo, while supporting bone formation.

Induction of Osseointegration by Nacre in Pigs

Nacre is a biomaterial that has shown osteoinductive and osteoconductive properties in vitro and in vivo. These properties make nacre a material of interest for inducing bone regeneration. However, information is very limited regarding the introduction of nacre to dental implant surgery for promoting osteogenesis. This study investigated the potential of nacre powder for peri-implant bone regeneration in a porcine model. Ninety-six dental implants were placed into the tibia of twelve male domestic pigs. The dental implants were coated with nacre powder from the giant oyster before implantation. Implantations without nacre powder were used as control groups. Euthanization took place at 2, 4 and 6 weeks after implantation, after which we measured bone-to-implant contact (BIC) and bone volume density (BVD) of the implanted bone samples using micro-computed tomography (micro-CT), and examined the histology of the surrounding bone using histological sections stained with Stevenel’s blue and Alizarin red S. The micro-CT analyses showed that the BIC of dental implantations with nacre powder were significantly higher than those without nacre powder, by 7.60%. BVD of implantations with nacre powder were significantly higher than those without nacre powder, by 12.48% to 13.66% in cortical bone, and by 3.37% to 6.11% in spongy bone. Histological study revealed more peri-implant bone regeneration toward the surface of the dental implants after implantation with nacre powder. This was consistent with the micro-CT results. This study demonstrates the feasibility of using nacre to promote peri-implant bone regeneration in dental implantation.

Extraction, Purification, Bioactivities and Application of Matrix Proteins From Pearl Powder and Nacre Powder: A Review

Natural pearls are formed when sand or parasites (irritants) accidentally enter into the oyster body and form pearls under the cover of the nacre layer. Pearl powder is a powdery substance by grinding pearls into small grains, however, the nacre powder is the inner layer of outer corner layer and middle prism layer. Pearl medicine in China has a history of more than 2,000 years, pearl has the effects of calming the mind, clearing the eyes, detoxifying the muscle and so on. In this paper, the researches on the extraction of pearl powder and nacre powder, the isolation and purification of matrix protein and the various biological activities (osteogenic activity, antioxidant, anti-inflammatory, anti-apoptotic, promoting the migration of fibroblasts, and so on) are reviewed in detail. To provide readers with a faster understanding, the method of extraction and purification and the application of nacre powder and pearl powder are clearly presented in the form of figures and tables. In line with the concept of waste or by-product, there are more reports of nacre extract than pearl extract, due to the expensive and limited in origin of pearls. Mainly on the direct use of nacre powder and pearl powder or on the use of extracts (mainly water soluble proteins) through experiments in vivo or in vitro, and shows whether it is effective through the results of various indexes. There is no further study on substances other than extracts, and the structural analysis of extracts needs further exploration.

Bone regeneration of a polymeric sponge technique-Alloplastic bone substitute materials compared with a commercial synthetic bone material (MBCP+TM technology): A histomorphometric study in porcine skull

Background

Polymeric sponge technique is recommended for developing the desired porosity of Biphasic calcium phosphate (BCP) which may favor bone regeneration.

Purpose

To investigate the healing of BCP with ratio of HA30/β‐TCP70 (HA30) and HA70/β‐TCP30 (HA70) polymeric sponge preparation, compare to commercial BCP (MBCP+TM).

Materials and Methods

Materials were tested X‐ray diffraction (XRD) pattern and scanning electron microscope (SEM) analysis. In eight male pigs, six calvarial defects were created in each subject. The defects were the filled with 1 cc of autogenous bone, MBCP+TM (MBCP), HA30, HA70, and left empty (negative group). The new bone formations, residual material particles and bone‐to‐graft contacts were analyzed at 4, 8, 12 and 16 weeks.

Results

Fabricated BCP showed well‐distributed porosity. At 16 weeks, new bone formations were 45.26% (autogenous), 33.52% (MBCP), 24.34% (HA30), 19.43% (HA70) and 3.37% (negative). Residual material particles were 1.88% (autogenous), 17.58% (MBCP), 26.74% (HA30) and 37.03% (HA70). These values were not significant differences (Bonferroni correction <0.005). Bone‐to‐graft contacts were 73.68% (MBCP), which was significantly higher than 41.68% (HA30) and 14.32% (HA70; Bonferroni correction <0.017).

Conclusions

Polymeric sponge technique offers well‐distributed porosity. The new bone formation and residual material particles were comparable to MBCP+TM, but the bone‐to‐graft contact was lower than MBCP+TM.

Progress in Modern Marine Biomaterials Research

The growing demand for new, sophisticated, multifunctional materials has brought natural structural composites into focus, since they underwent a substantial optimization during long evolutionary selection pressure and adaptation processes. Marine biological materials are the most important sources of both inspiration for biomimetics and of raw materials for practical applications in technology and biomedicine. The use of marine natural products as multifunctional biomaterials is currently undergoing a renaissance in the modern materials science. The diversity of marine biomaterials, their forms and fields of application are highlighted in this review. We will discuss the challenges, solutions, and future directions of modern marine biomaterialogy using a thorough analysis of scientific sources over the past ten years.

Immunohistopathologic evaluation of Drynaria fortunei rhizome extract in the management of Class II furcation defects in a canine model

BACKGROUND

Management of furcation defects is still a challenging subject in periodontal therapy. Drynaria fortunei (Df) is a common type of traditional Chinese herb in the area of orthopedics and traumatology. In vitro and tissue engineering studies have shown that Df induces osteoblastic proliferation and promotes the differentiation of human periodontal ligament cells. This study investigated the management of Class II furcation defects in dogs using guided tissue regeneration (GTR) and Df granules mixed with β-tricalcium phosphate (β- TCP) alloplast.

METHODS

Sixteen Class II critical-sized furcation defects were surgically created in four mongrel dogs: Eight defects were treated with GTR and Df granules mixed with (β-TCP) alloplast served as the experimental group, while the other eight were managed with GTR and alloplast, served as control. Dogs were sacrificed at 4 and 8 weeks and the premolars were processed for the evaluation of treatment outcome including; osteoblastic count (OC), cementum layer thickness (CLT), percentage of collagen in bone matrix (CBM), and alkaline phosphatase (ALP) immunoreaction.

RESULTS

Experimental group treated with Df showed a significant increase (P < 0.001) in the values of OC, CLT, CBM, and ALP immunoreactivity when compared with control at 4 and 8 weeks after treatment.

CONCLUSION

Drynaria fortunei demonstrated increased regeneration and bone formation when used in the treatment of furcation defects in a canine model.

Bone substitute made from a Brazilian oyster shell functions as a fast stimulator for bone-forming cells in an animal model

Despite their demonstrated biocompatibility and osteogenic properties, oyster shells have been reported as a potential alternative to other commonly used materials for bone substitution. This study evaluated whether an experimental bone substitute (EBS) made from a typical oyster shell of Northeastern Brazil (Crassostrea rhizophora) has effects on bone development using an animal model. Oysters were collected from a biologically assisted vivarium, and their inner layer was used for preparing an EBS. Chemical and surface characterization of EBS was performed using Individually Coupled Plasma Optical Emission Spectrometry (ICP-OES) and Scanning Electron Microscope (SEM), respectively. Seventy-two rats were randomly assigned to groups according to the treatment of bone defects created in the submandibular area: Negative Control (-C), Positive Control (+C; Bio-Oss®) and EBS. Euthanasia occurred at 7, 21, 42 and 56 days postoperatively. The bone pieces were stained with hematoxylin and eosin (H&E). The formation of bone tissue was evaluated histologically and histomorphometrically. Data were analyzed through the Kruskal-Wallis test and ANOVA considering a significant level of 5%. The main element found in EBS was calcium (71.68%), and it presented heterogeneity in the particle size and a porosity aspect at SEM analysis. Histological results revealed the absence of inflammatory cells in all groups, being that EBS presented the most accelerated process of bone formation with a statistically significant difference between this group and the +C and -C groups in the 21-day time-point (p < 0.05). After 21 days, the bone formation process was similar between all groups (p > 0.05), showing an immature lamellar bone pattern after 56 days of experimentation (p > 0.05). Within the limitations of this study, it was possible to conclude that EBS presented good biocompatibility and promoted fast stimulation for bone-forming cells in an animal model.

Nacre, a natural, multi-use, and timely biomaterial for bone graft substitution

During the past two decades, with a huge and rapidly increasing clinical need for bone regeneration and repair, bone substitutes are more and more seen as a potential solution. Major innovation efforts are being made to develop such substitutes, some having advanced even to clinical practice. It is now time to turn to natural biomaterials. Nacre, or mother-of-pearl, is an organic matrix-calcium carbonate coupled shell structure produced by molluscs. In vivo and in vitro studies have revealed that nacre is osteoinductive, osteoconductive, biocompatible, and biodegradable. With many other outstanding qualities, nacre represents a natural and multi-use biomaterial as a bone graft substitute. This review aims at summarising the current needs in orthopaedic clinics and the challenges for the development of bone substitutes; most of all, we systematically review the physiological characteristics and biological evidence of nacre's effects centred on osteogenesis, and finally we put forward the potential use of nacre as a bone graft substitute. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 662-671, 2017.

Comparison of histological and three-dimensional characteristics of porous titanium granules and deproteinized bovine particulate grafts used for sinus floor augmentation in humans: a pilot study

PURPOSE

Slow-resorbing deproteinized bovine bone grafts have presented high success rates when used for sinus augmentation. However, histologic evaluation shows that this material is eventually excreted as a result of a foreign body reaction. The purpose of this study was to compare and to evaluate the performance of a recently introduced particulate porous graft material, consisting of pure titanium granule (PTG) to the deproteinized bovine bone grafts, when used as a sinus augmentation material.

MATERIALS AND METHODS

To understand the histological aspects of PTG, deproteinized bovine particulates (Bio-Oss) and PTG were placed contralaterally as sinus grafting materials in 2 patients. After 9 months, biopsies were performed for histologic and 3-dimensional analysis.

RESULTS

Both materials were in contact with newly formed bone. The Bio-Oss showed signs of foreign body reaction. In contrast, bone filled the space between the single PTG particulates, and no foreign body reaction was observed.

CONCLUSIONS

From a bone formation perspective, PTG grafts were comparable with the commonly used Bio-Oss grafts and may be regarded as a possible alternative for permanent grafting in sinus augmentation.

Shotgun proteomics analysis of proliferating STRO-1-positive human dental pulp cell after exposure to nacreous water-soluble matrix

INTRODUCTION

For dental treatment, dentin regeneration is required after a tooth injury with dental pulp exposure. The effects of the water-soluble matrix (WSM) extracted from the nacreous layer of the bivalve Pinctada maxima on human dental pulp cells in vitro were challenging and useful for clinical application.

MATERIAL AND METHODS

The biological activity of the STRO-1-positive human dental pulp cells in response to WSM compared to Dulbecco's modified Eagle medium (DMEM) as a normal control was monitored. The cell survival rate was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Proteomic profiles among inducers and noninducers with time dependency were compared by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis combined with liquid chromatography-tandem mass spectrometry (GeLC-MS/MS).

RESULTS

The human dental pulp cells cultured in nacreous WSM exhibited higher relative cell viability than those in DMEM with similar morphological appearance. Significant changes were found in the relative abundance of 44 proteins in cells after exposure to WSM for 2 weeks. They play a role in cell adhesion, cell proliferation, metabolic process, signal transduction, stress response, transcription, translation, and transport.

CONCLUSION

These results indicate that WSM of P. maxima has the ability to induce proliferation of human dental pulp cells.

CLINICAL RELEVANCE

This finding initiated the study to evaluate the suitability of nacre as biomaterial for dentistry.

Calcium orthophosphates in dentistry

Dental caries, also known as tooth decay or a cavity, remains a major public health problem in the most communities even though the prevalence of disease has decreased since the introduction of fluorides for dental care. Therefore, biomaterials to fill dental defects appear to be necessary to fulfill customers' needs regarding the properties and the processing of the products. Bioceramics and glass-ceramics are widely used for these purposes, as dental inlays, onlays, veneers, crowns or bridges. Calcium orthophosphates belong to bioceramics but they have some specific advantages over other types of bioceramics due to a chemical similarity to the inorganic part of both human and mammalian bones and teeth. Therefore, calcium orthophosphates (both alone and as components of various formulations) are used in dentistry as both dental fillers and implantable scaffolds. This review provides brief information on calcium orthophosphates and describes in details current state-of-the-art on their applications in dentistry and dentistry-related fields. Among the recognized dental specialties, calcium orthophosphates are most frequently used in periodontics; however, the majority of the publications on calcium orthophosphates in dentistry are devoted to unspecified "dental" fields.