Evaluation of bone healing with eggshell-derived bone graft substitutes in rat calvaria: A pilot study

Influence of physicochemical characteristics of calcium phosphate-based biomaterials in cranio-maxillofacial bone regeneration. A systematic literature review and meta-analysis of preclinical models

Objectives

Calcium phosphate-based biomaterials (CaP) are the most widely used biomaterials to enhance bone regeneration in the treatment of alveolar bone deficiencies, cranio-maxillofacial and periodontal infrabony defects, with positive preclinical and clinical results reported. This systematic review aimed to assess the influence of the physicochemical properties of CaP biomaterials on the performance of bone regeneration in preclinical animal models.

Methods

The PubMed, EMBASE and Web of Science databases were searched to retrieve the preclinical studies investigating physicochemical characteristics of CaP biomaterials. The studies were screened for inclusion based on intervention (physicochemical characterization and in vivo evaluation) and reported measurable outcomes.

Results

A total of 1532 articles were retrieved and 58 studies were ultimately included in the systematic review. A wide range of physicochemical characteristics of CaP biomaterials was found to be assessed in the included studies. Despite a high degree of heterogeneity, the meta-analysis was performed on 39 studies and evidenced significant effects of biomaterial characteristics on their bone regeneration outcomes. The study specifically showed that macropore size, Ca/P ratio, and compressive strength exerted significant influence on the formation of newly regenerated bone. Moreover, factors such as particle size, Ca/P ratio, and surface area were found to impact bone-to-material contact during the regeneration process. In terms of biodegradability, the amount of residual graft was determined by macropore size, particle size, and compressive strength.

Conclusion

The systematic review showed that the physicochemical characteristics of CaP biomaterials are highly determining for scaffold's performance, emphasizing its usefulness in designing the next generation of bone scaffolds to target higher rates of regeneration.

Natural Biomaterials from Biodiversity for Healthcare Applications

Natural biomaterials originating during the growth cycles of all living organisms have been used for many applications. They span from bioinert to bioactive materials including bioinspired ones. As they exhibit an increasing degree of sophistication, natural biomaterials have proven suitable to address the needs of the healthcare sector. Here the different natural healthcare biomaterials, their biodiversity sources, properties, and promising healthcare applications are reviewed. The variability of their properties as a result of considered species and their habitat is also discussed. Finally, some limitations of natural biomaterials are discussed and possible future developments are provided as more natural biomaterials are yet to be discovered and studied.

Eggshell Microparticle Reinforced Scaffolds for Regeneration of Critical Sized Cranial Defects

Scaffold-based approaches for bone regeneration have been studied using a wide range of biomaterials as reinforcing agents to improve the mechanical strength and bioactivity of the 3D constructs. Eggshells are sustainable and inexpensive materials with unique biological and chemical properties to support bone differentiation. The incorporation of eggshell particles within hydrogels yields highly osteoinductive and osteoconductive scaffolds. This study reveals the effects of microparticles of whole eggshells, eggshells without a membrane, and a pristine eggshell membrane on osteogenic differentiation in protein-derived hydrogels. The in vitro studies showed that gels reinforced with eggshells with and without a membrane demonstrated comparable cellular proliferation, osteogenic gene expression, and osteogenic differentiation. Subsequently, in vivo studies were performed to implant eggshell microparticle-reinforced composite hydrogel scaffolds into critical-sized cranial defects in Sprague Dawley (SD) rats for up to 12 weeks to study bone regeneration. The in vivo results showed that the eggshell microparticle-based scaffolds supported an average bone volume of 60 mm³ and a bone density of 2000 HU 12 weeks post implantation. Furthermore, histological analyses of the explanted scaffolds showed that the eggshell microparticle-reinforced scaffolds permitted tissue infiltration and induced bone tissue formation over 12 weeks. The histology staining also indicated that these scaffolds induced significantly higher bone regeneration at 6 and 12 weeks as compared to the blank (no scaffold) and pristine gel scaffolds. The eggshell microparticle-reinforced scaffolds also supported significantly higher bone formation, remodeling, and vascularization over 6 and 12 weeks as confirmed by immunohistochemistry analysis. Collectively, our results indicated that eggshell microparticle-reinforced scaffolds facilitated significant bone regeneration in critical-sized cranial defects.

The effect of extraction time on the physicochemical characteristics of nanocalcium powder from chicken and duck eggshells

Calcium deficiency is associated with the risks of bone fracture and osteoporosis. This type of malnutrition has been a concern of governments and the World Health Organization for decades, and extensive efforts have been made to address it. There are several solutions to increase calcium intake. One is to take calcium in the form of nanocalcium. The objective of the present research was to determine the effect of extraction time on the physicochemical characteristics of nanocalcium powder extracted from chicken and duck eggshells through precipitation. This research was conducted by using a completely randomized factorial design with two factors, and each treatment analysis was repeated three times. The first factor was the type of eggshell (chicken and duck), and the second was the extraction time (1, 1.5, and 2 hours). The observed parameters were physical (yield and color) and chemical characteristics (moisture, ash, calcium content, and crystalline structure). The results showed that the type of eggshell had a significant effect (p <0.05) on yield, color (lightness), and moisture content and that extraction time had a significant effect (p <0.05) on yield, color (chroma and hue), moisture, and ash content. The highest content of the crystalline structure of nanocalcium formation (100%) was nanocalcium powder from chicken and duck eggshells, with 1 hour of extraction time. The particle size of the crystalline structure of nanocalcium from chicken and duck eggshells were 41.54 nm and 24.90 nm, respectively.

Evaluation of Guided Bone Regeneration in Critical Defects Using Bovine and Porcine Collagen Membranes: Histomorphometric and Immunohistochemical Analyses

Guided bone regeneration (GBR) is a technique used to facilitate bone regeneration, which uses a biocompatible membrane acting as a physical barrier to prevent the adjacent connective tissue from invading the bone defect. The aim of this study was to evaluate and compare the effectiveness of bovine and porcine collagenous membranes as barriers to connective tissue invasion during the repair of critical bone defects in rat calvaria, using histological, histometric, and immunohistochemical analyses. For this study, 72 rats were divided into three groups: clot group (CG), bovine collagen group (BCG), and porcine collagen group (PCG). Analyses were performed on days 7, 15, 30, and 60. The histological results showed that the PCG exhibited bone neoformation starting from day 7, and after 30 days of repair, the surgical defect was completely filled in some animals. For the BCG, there was little bone neoformation activity in the initial periods, and from day 30 onwards, there was an increase in bone neoformation, with a greater increase on day 60. The data obtained in the histometric analysis reveal that, on day 30, the neoformed bone area did not vary greatly between the PCG and the BCG, though both varied from the CG. By day 60, the PCG presented a greater area of neoformation than the BCG. These results were corroborated by the immunohistochemistry results. In view of the results obtained, it can be concluded that all membranes studied in this research promoted GBR.

Probiotic yogurt supplemented with nanopowdered eggshell: Shelf-life stability, physicochemical, and sensory characteristics

The objectives of this study were to produce probiotic yogurt (5.0-7.0 log cfu/g) fortified with nanopowdered eggshell (NPES) at a rate of 0.02, 0.04, and 0.06 mg/ml, as well as, examine the effect of NPES on the physicochemical, microbial, sensory properties, and shelf-life of probiotic yogurt. The NPES was prepared by milling preboiled dried eggshell using a mortar grinder. The size of the milled powder was measured to assure that the diameter of the powder is 27 ± 1.7 nm. Yogurt was manufactured by dividing the pasteurized milk into four aliquots portions. The first portion was utilized as control (T1), while the other three portions were supplemented with 0.02 (T2), 0.04 (T3), and 0.06 (T4) mg/ml NPES. All treatments were inoculated with 5.11 log cfu of Lactobacillus delbruckii ssp. bulgaricus (Lb) and Streptococcus thermophilus (St) combined and 5 log cfu of Bifidobacterium bifidum (Bb) per kg of milk at 40°C until the pH of 4.6 was reached. The acidity, sensory properties, Bb count, total bacterial count (TBC), yeast, and mold counts were examined. The results showed that the acidity was increasing during storage, however, increasing NPES resulted in low acid development (p < .05). The shelf-life of control was ended after 8 d of storage at 4°C because molds were grown on the surface of the sample. The TBC significantly decreased (p < .05) as the concentration of NPES increased. Bb count in probiotic yogurt was also decreasing during storage. Yeast and molds were detected in control after 8 d; however, NPES did not result in molds even after 16 d of storage but yeast was exhibited. The NPES improved the sensory evaluation of probiotic yogurt slightly and increased the shelf-life of probiotic yogurt as compared to control.

The Influence of Eggshell on Bone Regeneration in Preclinical In Vivo Studies

Simple Summary

The aim of this study is to review the available information on the use of avian eggshell as bone regeneration material. Five databases were searched up to October 2020. Animal studies with a bone defect model using eggshell as a grafting material were included. Risk of bias and the quality of the papers were assessed. Overall, a total of 581 studies were included in the study, 187 after duplicate removal. Using the inclusion and exclusion criteria 167 records were further excluded. The full text of the remaining 20 articles was assessed for eligibility and included in the review. There were different methods of obtaining eggshell for grafting purposes. Eggshell is a biocompatible grafting material, with bone formation capabilities. It forms new bone similar to other products currently in use in clinical practice. It can be combined with other materials to enhance its proprieties. Eggshell is a promising biomaterial to be used in bone grafting procedures, though further research is needed.

Abstract

The aim of this study is to systemically review the available evidence on the in vivo behavior of eggshell as a guided bone regeneration substitute material. Five databases (PubMed, Cochrane, Web of Science, Scopus, EMBASE) were searched up to October 2020. In vivo animal studies with a bone defect model using eggshell as a grafting material were included. Risk of bias was assessed using SYRCLE tool and the quality assessment using the ARRIVE guidelines. Overall, a total of 581 studies were included in the study, 187 after duplicate removal. Using the inclusion and exclusion criteria 167 records were further excluded. The full text of the remaining 20 articles was assessed for eligibility and included in the qualitative and quantitative assessment synthesis. There were different methods of obtaining eggshell grafting materials. Eggshell is a biocompatible grafting material, with osteoconduction proprieties. It forms new bone similar to Bio-Oss and demineralized freeze-dried bone matrix. It can be combined with other materials to enhance its proprieties. Due to the high variability of the procedures, animals, production and assessment methods, no meta-analysis could be performed. Eggshell might be considered a promising biomaterial to be used in bone grafting procedures, though further research is needed.

Clinical applications of avian eggshell-derived hydroxyapatite

The search for bone reconstruction materials and methods is an ongoing challenge. The aim of this review is to systemically search the available literature concerning the clinical performance of eggshell as a substitute material in guided bone regeneration in oral surgery. Five databases (PubMed, Cochrane, Web of Science, Scopus, and Embase) were searched up to February 2020. Clinical trials that used eggshell as a bone substitute material were included in the review. Animal and in vivo studies were excluded from the review. ROBINS-I was used to evaluate the risk of bias. A total of 840 studies were retrieved, out of which 55 full-text articles were screened. Five studies were finally included: one study showed critical and four serious risk of bias. A total of 74 patients and 88 intervention sites were included in the five studies. Clinical and radiological evaluation showed complete healing during the follow-ups. Statistically significant radiological and clinical evidence of new bone formation was achieved for socket preservation, grafting after third molar extraction, and cystic/apicectomy grafting. One patient with complications was reported. Histological analysis and micro computed tomography confirmed that it promotes bone regeneration. A comparison with synthetic hydroxyapatite showed similar healing characteristics. Within the limitations of the included studies, the eggshell can be safely and efficiently used in guided bone regeneration procedures, but more research is needed to completely evaluate the full potential of this material.

Cytotoxic effect of natural cuttlefish bone xenograft: an <em> in vitro </em> and <em> in vivo </em> study

BACKGROUND Commercialized synthetic bone grafts are commonly used to replace the bone defect. Cuttlefish bone is naturally available and widely studied, but the specific cytotoxicity test has not been conducted. This study aimed to evaluate the cytotoxicity of the xenograft compared to commercial grafts.  METHODS We performed an in vitro test evaluating the viability of human mesenchymal stem cells (hMSCs) when cultured for 48 hours with the tested materials (cuttlefish bone graft and fabricated PerOssal®). The trypsinized mitochondrial activity of the viable hMSC was assayed based on colorimetry of the formazan color change. The tested material was considered nontoxic if >70% of the hMSCs were viable. The in vivo cytotoxic effect was evaluated by implanting the graft material in the femoral muscle of New Zealand (NZ) white rabbits. Nine rabbits were used in each test (cuttlefish bone, PerOssal®, and NaCl 0.9%). The systemic acute pyrogenic effect was evaluated based on 72 hours body weight changes and rectal temperature changes every 30 min in the first 3 hours and 72 hours post-implantation.  RESULTS The mean percentage of hMSC viability when cultured with cuttlefish bone graft and PerOssal® was comparable (93.47% and 105.37%, respectively, p = 0.240). The in vivo cytotoxicity on NZ rabbit was similar between all tested materials, as shown by the minor changes in body weight (<10% body weight, p = 0.391) and rectal temperature (<0.5°C, p = 0.127).  CONCLUSIONS Cuttlefish bone xenograft and fabricated PerOssal® have a similar non-cytotoxic effects on hMSCs and non-pyrogenic systemic effects on rabbits.

Osteopromotion Capacity of Bovine Cortical Membranes in Critical Defects of Rat Calvaria: Histological and Immunohistochemical Analysis

Membranes that aid the guided bone regeneration (GBR) process have been the subject of studies of compatible biomaterials that contribute to this repair process. The present study compared different membranes used in critical-size defects of rat calvaria by assessing GBR as well as histological, histomorphometric, and immunohistochemical reactions. Forty-eight male albino Wistar rats were randomly allocated into four groups (n = 12 each), namely, C: membrane-free control group (only blood clot, negative control group); BG: porcine collagen membrane group (Bio-Gide®, positive control group); GD: bovine cortical membrane group (first experimental group); and GDF: thicker bovine cortical membrane group (second experimental group). Rats were euthanized at 30 and 60 days postoperatively. Quantitative data from the histometric analysis were submitted to two-way ANOVA and Tukey's posttest when p < 0.05. Histomorphometric results of the thicker bovine cortical membrane at 30 and 60 days were promising, showing improved new bone formation values (p < 0.05), and the CD group presented similar results in both analysis periods, being surpassed only by the GDF group (p < 0.05). The immunohistochemical results were associated with the histomorphometric data. A less-thick membrane also assisted in GBR. All membranes promoted GBR, especially the positive control and experimental groups.

Socket preservation using eggshell-derived nanohydroxyapatite with platelet-rich fibrin as a barrier membrane: a new technique

Objectives

Socket grafting is vital to prevent bone resorption after tooth extraction. Several techniques to prevent resorption have been described, and various bone graft substitutes have been developed and used with varying success. We conducted this pilot study to evaluate the performance of nanohydroxyapatite (nHA) derived from chicken eggshells in socket preservation.

Materials and Methods

This was a prospective, single center, outcome assessor-blinded evaluation of 23 sockets (11 patients) grafted with nHA and covered with platelet-rich fibrin (PRF) membrane as a barrier. Bone width and radiographic bone density were measured using digital radiographs at 1, 12, and 24 weeks post-procedure. Postoperative histomorphometric and micro-computed tomography (CT) evaluation were performed. The study protocol was approved by the Institutional Ethics Committee.

Results

All patients had uneventful wound healing without graft material displacement or leaching despite partial exposure of the grafted socket. Tissue re-epithelialized with thick gingival biotype (>3 mm). Width of the bone was maintained and radiographic density increased significantly with a trabecular pattern (73.91% of sockets) within 12 weeks. Histomorphometric analysis showed 56.52% Grade 3 bone formation and micro-CT analysis revealed newly formed bone with interconnecting trabeculae.

Conclusion

Use of a PRF membrane with nHA resulted in good bone regeneration in sockets. Use of a PRF membrane prevents periosteal-releasing incisions for primary closure, thereby facilitating the preservation of keratinized mucosa and gingival architecture. This technique, which uses eggshell-derived nHA and PRF membrane from the patient's own blood, is innovative and is free of disease transfer risks. nHA is a promising economic bone graft substitute for bone regeneration and reconstruction because of the abundant availability of eggshell waste as a raw material.

Elaboration and Biocompatibility of an Eggshell-Derived Hydroxyapatite Material Modified with Si/PLGA for Bone Regeneration in Dentistry

Hydroxyapatite (HAp) is the most commonly used biomaterial in modern bone regeneration studies because of its chemical similarity to bone, biocompatibility with different polymers, osteoconductivity, low cost, and lack of immune response. However, to overcome the disadvantages of HAp, which include fragility and low mechanical strength, current studies typically focus on property modification through the addition of other materials. Objective. To develop and evaluate the biocompatibility of a HAp material extracted from eggshells and modified with silicon (Si) and poly(lactic-co-glycolic) acid (PLGA). Materials and Methods. An in vitro experimental study in which a HAp material prepared from eggshells was synthesized by wet chemical and conventional chemical precipitation. Subsequently, this material was reinforced with Si/PLGA using the freezing/lyophilization method, and then osteoblast cells were seeded on the experimental material (HAp/Si/PLGA). To analyse the biocompatibility of this composite material, scanning electron microscopy (SEM) and fluorescence confocal microscopy (FCM) techniques were used. PLGA, bovine bone/PLGA (BB/PLGA), and HAp/PLGA were used as controls. Results. A cellular viability of 96% was observed for the experimental HAp/Si/PLGA material as well as for the PLGA. The viability for the BB/PLGA material was 90%, and the viability for the HAp/PLGA was 86%. Cell adhesion was observed on the exterior surface of all materials. However, a continuous monolayer and the presence of filopodia were observed over both external and internal surface of the experimental materials. Conclusions. The HAp/Si/PLGA material is highly biocompatible with osteoblastic cells and can be considered promising for the construction of three-dimensional scaffolds for bone regeneration in dentistry.

Cytotoxic and the proliferative effect of cuttlefish bone on MC3T3-E1 osteoblast cell line

Objective:

To evaluate the cytotoxic and the proliferative effect of cuttlefish bone on MC3T3-E1 osteoblast cell line.

Materials and Methods:

MC3T3-E1 cells were treated with 0.5, 1, 5, 25, 50, 100, or 200 μg/ml cuttlefish bone powder (CBP). Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. This assay was also used to determine cell proliferation over 16 days of treatment with 0.5, 25, or 100 μg/ml CBP.

Results:

CBP was not cytotoxic to MC3T3-E1 cells at any concentration. The percentage of cell viability in the 0.5–200 μg/ml CBP groups dose dependently decreased from 107.52 ± 11.03 to 92.48 ± 5.60%; however, the differences between the groups or the negative control group were not significant. At 16 days, 0.5, 25, and 100 μg/ml CBP groups showed 123.19 ± 10.07%, 126.02 ± 15.69%, and 133.33 ± 11.74% proliferation, respectively, that were significantly higher than that of the control group.

Conclusion:

These results indicate that CBP promotes osteoblast proliferation and may be a potential material to increase the number of osteoblasts in a bone defect in the oral cavity.

Histomorphometric evaluation of a nano-sized eggshell-containing supplement as a natural alloplast: An animal study

Background

Limitations of autogenous grafts have dictated the need for development of new biomaterials that can serve as allografts. A paradigm shift directed manufacturers to revert to nature in the search for such allografts. This study aimed to evaluate an eggshell-based supplement, Membrell’s® BONEhealth Plus D₃ & K₂, indicated to support bone mineral density, as a natural bone graft material.

Methods

Twelve 5 × 10 × 1 mm full-thickness cranial bone defects were created in six adult male New Zealand rabbits. Six defects were filled with Membrell’s® BONEhealth™ Plus D₃ & K_2, and the others were left empty as control. The animals were sacrificed 14 days postoperatively. The defects were dissected and prepared for histological assessment. Bone formation was compared both qualitatively and quantitatively. The area percent of newly-formed bone was evaluated in five successive regions using image analysis. Statistical analysis was performed using unpaired t-test. Differences between the two groups were considered significant at p ≤ 0.05.

Results

Cranial bone defects filled with the nano-sized eggshell powder “Membrell’s® BONEhealth™ Plus D₃ & K₂” revealed significantly higher levels of osteoid, newly-formed, regularly-arranged bone trabeculae in the center of the defects (47.37% ± 1.12) compared to the control defects (21.6% ± 4.92), which revealed no bone formation. A rapid rate of resorption of the nano-sized eggshell powder and consequently a rapid osteogenic effect was evident.

Conclusions

The eggshell-based graft powder, Membrell’s® BONEhealth™ Plus D₃ & K₂, is a biocompatible material which has the potential to enhance new bone formation.

Natural bioceramics: our experience with changing perspectives in the reconstruction of maxillofacial skeleton

Objectives

Various bone graft substitute materials are used to enhance bone regeneration in the maxillofacial skeleton. In the recent past, synthetic graft materials have been produced using various synthetic and natural calcium precursors. Very recently, eggshell-derived hydroxyapatite (EHA) has been evaluated as a synthetic bone graft substitute. To assess bone regeneration using EHA in cystic and/or apicectomy defects of the jaws through clinical and radiographic evaluations.

Materials and Methods

A total of 20 patients were enrolled in the study protocol (CTRI/2014/12/005340) and were followed up at 4, 8, 12, and 24 weeks to assess the amount of osseous fill through digital radiographs/cone-beam computed tomography along with clinical parameters and complications. Wilcoxon matched pairs test, means, percentages and standard deviations were used for the statistical analysis.

Results

The sizes of the lesions in the study ranged from 1 to 4 cm and involved one to four teeth. The study showed significant changes in the formation of bone, the merging of material and the surgical site margins from the first week to the first month in all patients (age range, 15-50 years) irrespective of the size of the lesions and the number of teeth involved. Bone formation was statistically significant from the fourth to the eighth week, and the trabecular pattern was observed by the end of 12 weeks with uneventful wound healing.

Conclusion

EHA showed enhancement of bone regeneration, and healing was complete by the end of 12 weeks with a trabecular pattern in all patients irrespective of the size of the lesion involved. The study showed enhancement of bone regeneration in the early bone formative stage within 12 weeks after grafting. EHA is cost effective and production is environment friendly with no disease transfer risks. Thus, natural bioceramics will play an important role in the reduction of costs involved in grafting and reconstruction.

Application of nano-hydroxyapatite/chitosan scaffolds on rat calvarial critical-sized defects: A pilot study

BACKGROUND

The purpose of this pilot study was to evaluate for the first time the effect of 75/25 w/w nano-Hydroxyapatite/Chitosan (nHAp/CS) scaffolds on Guided Bone Regeneration (GBR) in rat calvarial critical-sized defects (CSDs).

MATERIAL AND METHODS

Six adult Sprague Dawley rats, 3 males and 3 females, were used. Two CSDs, full thickness and 5mm in diameter, were trephined in both sides of the parietal bone. The right CSD was filled with nHAp/CS scaffold, while the left CSD remained empty, as the control group. The wound was sutured in layers. Rats were euthanized with diethyl ether inhalation at 2, 4 and 8 weeks after surgical procedure. Histological and histomorphometric analysis was performed within distinct regions of interest (ROI): the lateral area inward of the middle sagittal seam; the lateral area outward of the middle sagittal seam and the central area.

RESULTS

The mean surface of newly formed bone (in μm2) in the lateral area inward of the middle sagittal seam of all rats was significantly higher (P=0.039) in the experimental group (91733.00±38855.60) than the control group (46762.17±25507.97). The NOex-c, defined as total number of osteocytes (OST) in newly formed bone surface in experimental group [experimental OST] minus the total number of osteocytes in newly formed bone surface in control group [control OST], was significantly greater (P=0.029) at 4th week post-surgery. Within the experimental group, a statistically significant increase (P=0.042) in the surface of newly formed bone was noticed in rats euthanized in 4th week compared with rats euthanized in 2nd week after surgery in the lateral area inward of the middle sagittal seam.

CONCLUSIONS

The results of this study suggest that 75/25 w/w nHAp/CS scaffolds should be considered as a suitable biomaterial for GBR.

Cell viability and hemocompatibility evaluation of a starch-based hydrogel loaded with hydroxyapatite or calcium carbonate for maxillofacial bone regeneration

The objective of this study is to evaluate the cell viability and hemocompatibility of starch-based hydrogels for maxillofacial bone regeneration. Seven starch-based hydrogels were prepared: three loaded with 0.5, 1 and 2% calcium carbonate (Sigma Aldrich, St. Louis, MO, USA); three loaded with 2, 3 and 4% hydroxyapatite (Sigma Aldrich); and one not loaded as a control. A 10 M NaOH was then added to induce hydrogel formation. Human osteoblasts were cultured on each hydrogel for 72 h. An MTS assay (Cell Titer96; PROMEGA, Madison, WI, USA) was used to assess cell viability. Hemocompatibility testing was conducted with normal human blood in the following conditions: 100 mg of each hydrogel in contact with 900 µL of whole blood for 15 min at 37 °C under lateral stirring. Higher percentages of cell viability were observed in starch-based hydrogels loaded with hydroxyapatite as compared with the control. The hemolysis test showed a hemolysis level lower than 2%. Activated partial thromboplastin time and prothrombin time were unchanged, while platelet counting showed a slight decrease when compared with controls.

Hydroxyapatite–-Past, Present, and Future in Bone Regeneration

Hydroxyapatite (HA) is an essential element required for bone regeneration. Different forms of HA have been used for a long time. The essence of bone regeneration always revolves around the healthy underlying bone or it may be the surroundings that give enough strength. HA is well known for bone regeneration through conduction or by acting as a scaffold for filling of defects from ancient times, but emerging trends of osteoinductive property of HA are much promising for new bone regeneration. Emerging technology has made the dreams of clinicians to realize the use of HA in different forms for various regenerative purposes both in vivo and in vitro. The nanostructured calcium apatite plays an important role in the construction of calcified tissues. The nanostructured material has the ability to attach biological molecules such as proteins, which can be used as functional materials in many aspects, and the capability of synthesizing controlled structures of apatite to simulate the basic structure of bone and other calcified tissues. The process of regeneration requires a biomimetic and biocompatible nanostructured novel material. The nanostructured bioceramic particles are of interest in synthetic bone grafts and bone cements both injectable and controlled setting, so that such composites will reinforce the strength of bioceramics. Extensive research is being carried out for bone regeneration using nanotechnology. Artificial bone formation is not far from now. Nanotechnology has made many dreams come true. This paper gives comprehensive insights into the history and evolution with changing trends in the use of HA for various regenerative purposes.

Effect of hydroxyapatite on critical-sized defect

Background

Xenologous or synthetic graft materials are commonly used as an alternative for autografts for guided bone regeneration. The purpose of this study was to evaluate effectiveness of carbonate apatite on the critical-size bone defect of rat’s calvarium.

Methods

Thirty-six critical-size defects were created on 18 adult male Sprague-Dawley rat calvaria under general anesthesia. Calvarial bones were grinded with 8 mm in daimeter bilaterally and then filled with (1) no grafts (control, n = 10 defects), (2) bovine bone mineral (Bio-Oss®, Geistlich Pharma Ag. Swiss, n = 11 defects), and (3) hydroxyapatite (Bongros®, Bio@ Inc., Seongnam, Korea, n = 15 defects). At 4 and 8 weeks after surgery, the rats were sacrificed and all samples were processed for histological and histomorphometric analysis.

Results

At 4 weeks after surgery, group 3 (42.90 ± 9.33 %) showed a significant difference (p < 0.05) compared to the control (30.50 ± 6.05 %) and group 2 (28.53 ± 8.62 %). At 8 weeks after surgery, group 1 (50.21 ± 6.23 %), group 2 (54.12 ± 10.54 %), and group 3 (50.92 ± 6.05 %) showed no significant difference in the new bone formation.

Conclusions

Bongros®-HA was thought to be the available material for regenerating the new bone formation.

Physicochemical and sensory properties of milk supplemented with dispersible nanopowdered oyster shell during storage

The current study was carried out to investigate the dispersibility of powdered oyster shell (POS), nanopowdered oyster shell (NPOS), and Zn-activated nanopowdered oyster shell (Zn-NPOS) in milk and to determine effects of adding oyster shell on the physicochemical and sensory properties of milk during storage at 4°C for 16 d. To ensure dispersibility, 10% (wt/vol) oyster shell was added to distilled water and stirred at 800 rpm for 2 h, and then the emulsifier 0.5% polyglycerol monostearate (PGMS) was added and stirred continually for 24 h. The particle sizes of POS, NPOS, and Zn-NPOS were 180μm, 389 nm, and 257 nm, respectively. The pH values of all milk samples ranged from 6.62 to 6.88 during storage, and the zeta-potential of milks with NPOS and Zn-NPOS added were more stable than that of milk with POS in low concentrations (0.5 and 1.0%, vol/vol) during storage. The L and a color values of the milks were not significantly influenced by treatment; however, the b value (yellow-blue color) significantly increased during storage after adding POS, NPOS, or Zn-NPOS. Sensory analysis revealed that sedimentation score significantly increased with POS-supplemented milk, but the NPOS- and Zn-NPOS-supplemented milks did not show sedimentation until after 8 d of storage. Based on the data obtained, we conclude that dispersible nanosized oyster shell at concentrations of 0.5 and 1.0% (vol/vol) could be supplemented to milk without significant adverse effects on physicochemical and sensory properties.

Enhanced bone regeneration by silicon-substituted hydroxyapatite derived from cuttlefish bone

OBJECTIVE

There is growing interest in the use of cuttlefish bone (CB) as a bone graft material. Silicon (Si) plays an important role in bone formation and calcification. This study aimed to prepare Si-substituted CB-derived hydroxyapatite (Si-CB-HAp) using a natural CB to improve the bioactivity for bone formation.

MATERIALS AND METHODS

We prepared Si-HAp from CB (Si-CB-HAp) using a hydrothermal and solvothermal method. The microstructure and chemical composition were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and energy dispersive X-ray spectrometer (EDS). The bioactivity of the Si-CB-HAp was evaluated using human mesenchymal stem cells. Furthermore, the in vivo bone regeneration efficiency was evaluated using a rabbit calvarial defect model.

RESULTS

Our results show that the Si content was 0.77 wt% in Si-CB-HAp, and its original microstructure was conserved. The presence of Si was shown to enhance cell proliferation and early cellular attachment of human mesenchymal stem cells. Additionally, results of alkaline phosphatase activity and real-time PCR for osteoblast marker genes show that Si substitution into CB-HAp enhanced osteoblast differentiation. In addition, in vivo bone defect healing experiments show that the formation of bone with Si-CB-HAp is higher than that with CB-HAp.

CONCLUSION

These results indicate that Si-CB-HAp may potentially be used as a bone graft material to enhance bone healing.

Effect of chicken egg shell powder solution on early enamel carious lesions: an invitro preliminary study

AIM

To evaluate the remineralization potential of enamel surface lesion using chicken eggshell powder (CESP) solution.

MATERIALS AND METHODS

Ten freshly extracted un-erupted third molars decoronated at cement-enamel junction (CEJ) used in this study. Each decoronated tooth was sectioned to get 4 samples of enamel blocks such that 40 blocks were obtained which were then subjected to demineralization protocol and grouped as: Group 1-untreated group, Group 2-subsurface demineralization, Group 3-subsurface demineralization + 7 days CESP immersion, Group 4- subsurface demineralization + clinpro application. The samples were evaluated for X-ray fluorescence spectroscopy analysis, microhardness testing and atomic analyses using energy dispersive X-ray spectroscopy. The data were statistically analysed by using one-way ANOVA and Tukey - Kramer multiple comparison test.

RESULTS

X-ray Fluorescence spectroscopy shows Calcium concentration of 98% and 0.46% of phosphate. Group 4 (Clinpro) shows the highest efficacy in enhancing the remineralization followed by Group 3 (CESP). The results of atomic analyses showed that quantitative amounts of Ca weight % and P weight % is statistically greater for all the three groups except the demineralized group.

CONCLUSION

CESP with higher calcium content can remineralise enamel surface lesion.

Physicochemical, microbial, and sensory properties of nanopowdered eggshell-supplemented yogurt during storage

This study was carried out to investigate the possibility of adding nanopowdered eggshell (NPES) into yogurt to improve the functionality of yogurt and the effects of adding NPES on the physicochemical, microbial, and sensory properties of the products during storage. The pH and mean lactic acid bacteria counts of NPES-added (0.15-0.45%, wt/vol) yogurt ranged from 4.31 to 4.66 and from 6.56 × 10(8) to 8.56 × 10(8)cfu/mL, respectively, whereas these values ranged from 4.13 to 4.44 and 8.46 × 10(8) to 1.39 × 10(9), respectively, for the control samples during storage at 5 °C for 16d, which indicates a prolonged shelf-life with NPES-supplemented yogurt. Color analysis showed that the lightness (L*) and position between red and green (a*) values were not significantly influenced by the addition of NPES. However, the position between yellow and blue (b*) value significantly increased with the addition of the concentration (0.45%, wt/vol) of NPES at d 16 of storage. Sensory evaluation revealed that NPES-added yogurts showed a notably less sourness score and a higher astringency score than the control. An earthy flavor was higher in 0.45% NPES-supplemented yogurt compared with the control. Based on the results obtained from the current study, the concentration (0.15 to 0.30%, wt/vol) of NPES can be used to formulate NPES-supplemented yogurt without any significant adverse effects on the physicochemical, microbial, and sensory properties.

Comparison of in vitro and in vivo bioactivity: cuttlefish-bone-derived hydroxyapatite and synthetic hydroxyapatite granules as a bone graft substitute

Bone reconstruction in clinical settings often requires bone substitutes. Hydroxyapatite (HAp) is a widely used bone substitute due to its osteoconductive properties and bone bonding ability. The aim of this study was to evaluate HAp granules derived from cuttlefish bone (CB-HAp) as a substitute biomaterial for bone grafts. In this study, HAp granules were prepared from raw CB by using a hydrothermal reaction. The formation of HAp from CB was confirmed by scanning electron microscopy and x-ray diffraction analysis. The bioactivity of the CB-HAp granules was evaluated both in vitro and in vivo. Our results show that CB-HAp is non-toxic and that CB-HAp granules supported improved cell adhesion, proliferation and differentiation compared to stoichiometric synthetic HAp granules. Furthermore, in vivo bone defect healing experiments show that the formation of bone with CB-HAp is higher than that with pure HAp. These results show that CB-HAp granules have excellent potential for use as a bone graft material.

A polycaprolactone/cuttlefish bone-derived hydroxyapatite composite porous scaffold for bone tissue engineering

Cuttlefish bone (CB) is an attractive natural biomaterial source to obtain hydroxyapatite (HAp). In this study, a porous polycaprolactone (PCL) scaffold incorporating CB-derived HAp (CB-HAp) powder was fabricated using the solvent casting and particulate leaching method. The presence of CB-HAp in PCL/CB-HAp scaffold was confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) and porosity analysis showed that the average pore dimension of the fabricated scaffold was approximately 200-300 μm, with ∼85% porosity, and that the compressive modulus increased after addition of CB-HAp powders. In vitro tests such as cell proliferation assay, cytotoxicity analysis, cell attachment observations, and alkaline phosphatase activity assays showed that the PCL/CB-HAp scaffold could improve the proliferation, viability, adherence, and osteoblast differentiation rate of MG-63 cells. When surgically implanted into rabbit calvarial bone defects, consistent with the in vitro results, PCL/CB-HAp scaffold implantation resulted in significantly higher new bone formation than did implantation of PCL alone. These findings suggest that addition of CB-HAp powder to the PCL scaffold can improve cellular response and that the PCL/CB-HAp composite scaffold has great potential for use in bone tissue engineering.

Improvement of the compressive strength of a cuttlefish bone-derived porous hydroxyapatite scaffold via polycaprolactone coating

Cuttlefish bones (CBs) have emerged as attractive biomaterials because of their porous structure and components that can be converted into hydroxyapatite (HAp) via a hydrothermal reaction. However, their brittleness and low strength restrict their application in bone tissue engineering. Therefore, to improve the compressive strength of the scaffold following hydrothermal conversion to a HAp form of CB (CB-HAp), the scaffold was coated using a polycaprolactone (PCL) polymer at various concentrations. In this study, raw CB was successfully converted into HAp via a hydrothermal reaction. We then evaluated their surface properties and composition by scanning electron microscopy and X-ray diffraction analysis. The CB-HAp coated with PCL showed improved compressive performance and retained a microporous structure. The compressive strength was significantly increased upon coating with 5 and 10% PCL, by 2.09- and 3.30-fold, respectively, as compared with uncoated CB-HAp. However, coating with 10% PCL resulted in a reduction in porosity. Furthermore, an in vitro biological evaluation demonstrated that MG-63 cells adhered well, proliferated and were able to be differentiated on the PCL-coated CB-HAp scaffold, which was noncytotoxic. These results suggest that a simple coating method is useful to improve the compressive strength of CB-HAp for bone tissue engineering applications.

Histologic and histomorphometric assessment of eggshell-derived bone graft substitutes on bone healing in rats

OBJECTIVE

The objective of this study was to histologically and histomorphometrically evaluate the efficacy of the new formulations of eggshell-derived calcium carbonate in rats.

STUDY DESIGN

The study was conducted on 30 adult male rats. Four standardized and circular intrabony defects were created in the both maxilla and mandibula of each animal. Three different graft materials were prepared as follows: 1) Material A: Eggshell-derived calcium carbonate combined with carrageenan gel, 2) Material B: Eggshell-derived calcium carbonate combined with xanthan gum gel, and 3) Material C: Eggshell-derived calcium carbonate powder. The right mandibular defect sites were grafted with Material A in all animals, and defects on the left were grafted with Material B. Defects on the right side of maxilla were received Material C in all animals, and all left maxillary defects were remained untreated as controls. The animals were sacrificed either postoperatively on the 15th day, postoperatively on the 30th day or postoperatively on the 45th day. Histomorphometric measurements were made of the areas of newly formed bone, necrotic bone, fibrous tissue and residual graft material.

RESULTS

Material A exhibited the highest level of osteoid formation followed by Material B and Material C on the 45th day. In terms of osteoid formation, statistically significant differences were observed between graft materials and controls at 45th day compared to 15th and 30th day (p<0.05).

CONCLUSIONS

Eggshell-derived graft substitutes in both gel and powder forms are biocompatible materials which may have the potential to enhance the new bone formation. Key words:Bone graft material, bone defects, eggshell, histopathological evaluation, rat.

Zinc-coated carbonate apatite derived from avian eggshell for potential use as bone substitute. Part I: preparation and properties

PURPOSE

To develop antibacterial bone substitutes derived from avian eggshell using microwave processing to convert natural calcium carbonate (CaCO3) into zinc-coated carbonate apatite (CHA).

METHODS

Zinc-coated carbonate apatite was prepared using domestic microwave and then characterized with scanning electron microscopy (SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and energy dispersive x-ray analysis (EDXA). The trial animal study was conducted by filling different bone substitutes into 5-mm-diameter standard defects on the parietal bone of New Zealand rabbits to observe new bone formation for 8 weeks.

RESULTS

SEM, XRD, FT-IR, and EDXA confirmed characteristics of zinc-coated CHA derived from avian eggshell using microwave method. Histological analysis demonstrated that the defects filled with carbonate apatite had more calcified bone and less uncalcified bone formation than other groups.

CONCLUSIONS

The present research demonstrated the efficient use of microwave in the conversion of natural CaCO3 into CHA with zinc coating. The examined properties showed the potential use of the new material as an antibacterial bone substitute in oral surgery. The trial animal study implied favorable osteoconductive ability of carbonate apatite in new bone formation.

Synthesis of three-dimensional calcium carbonate nanofibrous structure from eggshell using femtosecond laser ablation

BACKGROUND

Natural biomaterials from bone-like minerals derived from avian eggshells have been considered as promising bone substitutes owing to their biodegradability, abundance, and lower price in comparison with synthetic biomaterials. However, cell adhesion to bulk biomaterials is poor and surface modifications are required to improve biomaterial-cell interaction. Three-dimensional (3D) nanostructures are preferred to act as growth support platforms for bone and stem cells. Although there have been several studies on generating nanoparticles from eggshells, no research has been reported on synthesizing 3D nanofibrous structures.

RESULTS

In this study, we propose a novel technique to synthesize 3D calcium carbonate interwoven nanofibrous platforms from eggshells using high repetition femtosecond laser irradiation. The eggshell waste is value engineered to calcium carbonate nanofibrous layer in a single step under ambient conditions. Our striking results demonstrate that by controlling the laser pulse repetition, nanostructures with different nanofiber density can be achieved. This approach presents an important step towards synthesizing 3D interwoven nanofibrous platforms from natural biomaterials.

CONCLUSION

The synthesized 3D nanofibrous structures can promote biomaterial interfacial properties to improve cell-platform surface interaction and develop new functional biomaterials for a variety of biomedical applications.