The fabrication of hydroxyapatite mineralized hydrogels for bone tissue engineering

Bone is a complex but orderly mineralized tissue with hydroxyapatite(HA)as the inorganic phase and collagen as the organic phase.Inspired by natural bone tissues,HA-mineralized hydrogels have been widely designed and used in bone tissue engineering.HA is majorly utilized for the treatment of bone defects because of its excellent osteoconduction and bone inductivity.Hydrogel is a three-dimensional hydrophilic network structure with similar properties to the extracellular matrix(ECM).The combination of HA and hydrogels produces a new hybrid material that could effectively promote osteointegration and accelerate the healing of bone defects.In this review,the structure and growth of bone and the common strategies used to prepare HA were briefly introduced.Importantly,we discussed the fabrication of HA mineralized hydrogels from simple blending to in situ mineralization.We hope this review can provide a reference for the development of bone repair hydrogels.

A conceptual framework for characterizing mineralized waste rocks as future resource

Conventional mining practices do not extract all mineralized rocks due to prevailing economics.Improvement in mineral prices and processing recovery(technology)could potentially make mineralized waste rocks profitable.A well-integrated mining strategy that focuses on both economic and physical resource depletion is vital to the management of non-renewable mineral resources.In this paper,a conceptual framework that maximizes the benefits of mining and processing mineralized waste rocks as future resource is proposed.Governmental policy and technical reforms that ensure mining companies incorporate the proposed mineralized waste rocks management framework in their long-term strategic mine plans have been recommended.

U-Pb Zircon and Re-Os Molybdenite Geochronology of the W-Mo Mineralized Region of South Qinling, China, and their Tectonic Implications

A W-Mo mineralized region is located along the northern margin of the South Qinling tectonic belt of China. WMo mineralization occurs mainly in Cambrian–Ordovician clastic and carbonate rocks, and the ore bodies are structurally controlled by NW–SE-and NNE–SSW-striking faults. Evidence for magmatism in the area is widespread and is dominated by intermediate–felsic intrusives or apophyses, such as the Dongjiangkou, Yanzhiba, Lanbandeng, and Sihaiping granitic bodies. Quartz-vein-type mineralization and fault-controlled skarn-type mineralization dominate the ore systems, with additional enrichment in residual deposits. At present, there are few or insufficient studies on(1) the age of mineralization,(2) the relationship between intermediate–felsic granite and W-Mo mineralization,(3) the source of ore-forming materials, and(4) the metallogenic and tectonic setting of the mineralized area. In this paper, we present geochronology results for numerous intrusive granitic bodies in the South Qinling tectonic belt. U-Pb zircon geochronology of the Lanbandeng monzogranite and Wangjiaping biotite monzogranite yields ages of 222.7 ± 2.3 and 201.9 ± 1.8 Ma, respectively. In contrast to the Late Triassic age of the Lanbandeng monzogranite, the age of the newly discovered Wangjiaping biotite monzogranite places it at the Triassic–Jurassic boundary. Re-Os molybdenite geochronology on the Qipangou W-Mo deposit yielded a model age of 199.7 ± 3.9 Ma, indicating the deposit formed in the early Yanshanian period of the Early Jurassic. Granitoid intrusions in the mineralized area are characterized by composite granite bodies that crystallized at ca. 240–190 Ma. While there were multiple stages of intrusion, most occurred at 210–220 Ma, with waning magmatic activity at 200–190 Ma. The Re-Os age of molybdenite in the region is ca. 200–190 Ma, which may represent a newly discovered period of W-Mo metallogenesis that occurred during the final stages of magmatism. The heat associated with this magmatism drove ore formation and might have provided additional ore-forming components for metallogenesis(represented by the Wangjiaping biotite monzogranite). Ore materials in the mineralized area were derived from mixed crustal and mantle sources. Enrichment of the region occurred during intracontinental orogenesis in the late Indosinian–Yanshanian, subsequent to the main Indosinian collision. At this time, the tectonic environment was dominated by extension and strike-slip motion.

Repair of Rat Segmental Defects with Mineralized Collagen Grafts Combined with or without Mesenchymal Stem Cells and BMP-2

The aim of the present study was to investigate and compare the bone formation capacity with three different grafts. Four millimeter segmental defects were created in adult rat tibias and were either left empty （control defects） or implanted with （1） nano-hydroxyapatite/collagen/PIA （nHAC/PIA） composite, （2） nHAC/ PIA composite added with bone marrow mesenchymal tem cells （ BMSCs ）, （ 3 ） nHAC/ PIA composite added with bone morphogenetic protein 2 （ BMP- 2）. Radiographs of the defects were taken weekly post-surgery. After 1 or 2 months, the rats were eathaaized. Histologic analyses were performed on the harvested tissue. nHAC/ PIA composite could enhance the repair of rat tibia segmental defects. Addition of BMSCs or BMP- 2 to nHAC/ PIA led to an increase in osteogenesis, nHAC/ PIA composite could be an Meal alternative bone-grafi material and it could also be used as an Meal carrier of BMSCs or BMP- 2.

Mineralized and Osteoid Tissue from Dental Pulp Stem Cells on Micro-arc Oxidation Titanium in vitro

The presence of insufficient bone volume affects the implant healing and success.The aim of this study was to evaluate osteogenic capacity of dental pulp stem cells(DPSCs) on micro-arc oxidation(MAO) titanium surface.DPSCs were challenged at MAO and smooth titanium surface separately for different durations,and the bone marrow mesenchymal stem cells(BMSCs) served as the positive controls.The osteogenic capacity of DPSCs on MAO titanium surface was assessed by using scanning electron microscopy,energy dispersive spectroscopy,biochemical tests and real-time quantitative PCR.Data showed that DPSCs differentiated into osteoblasts and expressed bone morphogenetic genes on MAO titanium surface.The results of this study revealed that DPSCs had good potential to generate mineralized tissue on MAO titanium plates.The differential potential of DPSCs may be regulated by MAO titanium surface.The osteogenesis potential of DPSCs on the MAO titanium was similar with BMSCs.

Threats to the Thermal Mineralized Waters Used for Therapeutic Purposes in Jordan

Although Jordan is a country with very limited water resources, the country is rich in its thermal mineralized water possessing curative properties, historically used for the therapy of a variety of ailments. Due to the country’s increasing water demand resulting from population growth, urbanization, and industrialization, extractions from the groundwater sources feeding the thermal mineralized springs has started to affect negatively the discharged quantities from the springs. In addition, urbanization, mining activities, over-exploited groundwater resources in general and severe drop in the level of the Dead Sea are leading to declining discharge of springs in general, and thermal mineralized in special, deteriorating water quality and contamination by human activities. In this article, the current quantitative and qualitative situation of the thermal mineralized springs is given and the threats to their discharges and quantities are discussed. In addition, some water policy changes and measures are suggested to conserve these therapeutic waters for the use of generations to come and to alleviate their depletion and quality deterioration on the social and economic state of Jordan.

Diversity and Adaptations of Immature Diptera in Semiaquatic Habitats at Shorelines of Hypersaline Lakes in the Crimea,with a Brief Review of Diptera in Mineralized Bodies of Water

The order Diptera(Insecta)is one of animal groups most successful in the colonization of mineralized shallow aquatic and semiaquatic environments.At the same time,the taxonomic composition of Diptera,their role in

Combined Geoelectrical Approach DC and IP Methods in the Identification of the Mineralized Bodies Parallel to the NE-SW Tectonic Line of Kadei River: Case of Quartz or Pegmatite Gold Bearing Veins of Ngoura Subdivision (East Cameroon)

A geophysical investigation of subsurface structures using the Syscal Junior 48 resistivity-meter was conducted in Ngoura subdivision (East Cameroon) following a combined geoelectrical direct current (DC) approach involving Resistivity and IP methods. This investigation was allowed to collect data on forty-five (45) profiling lines at three acquisition levels (AB = 100 m, MN = 10 m;AB = 200 m, MN = 20 m and AB = 500 m, MN = 50 m) and two electric panels L1 and L4, using the Schlumberger array. Processing, modeling and interpretation of data collected using the Winsev, Res2Dinv and Surfer software helped in highlighting a conductive and strongly mineralized discontinuity in granite formations, which lined up with the NE-SW Kadei tectonic line. It extends beyond 100 m depth over an average width of 600 m. The mineralization associated with this discontinuity is identified by a high concentration of disseminated metalliferous minerals in quartz or pegmatite veins. The mining reconnaissance works in the study area and those of several authors have characterized this anomaly to a lode gold quartz or large pegmatite. The results of this study correlate with geological and tectonic data for the region marked by NE-SW Kadei tectonic line. Therefore, they confirm the reliability of a geoelectrical DC investigation method combining Resistivity and IP to the identification of ore bodies.

Geochemical characteristics and genetic type of a lithium ore (mineralized) body in the central Yunnan Province, China

Lithium ore (mineralized) bodies in the area A of central Yunnan Province belong to a sedimentary-type, which are controlled by stratum. The studied ore (mineralized) body mainly occurs in the Middle Permian Liangshan Formation. This work described the morphology, structures, main ore types and geochemical characteristics of this ore body in detail, and discussed the ore-forming material source, occurrence state of lithium and the formation mechanism of lithium ores to clarify the prospecting marks. In the further exploration, comprehensive evaluation of the lithium resources of known bauxite ore bodies in central Yunnan Province should be strengthened, and the exploration of hidden lithium ore bodies should be intensified in order to discover more large and super-large lithium orebodies, which will fill the gap of the national demand for lithium resources, and promote the national defense construction and new energy industry development.

Mineralized Composite Nanofibrous Mats for Bone Tissue Engineering

Composite nanofibrous mats consisting of poly( L-lactideco-ε-caprolactone)( PLCL) and collagen type I( COL) were fabricated by electrospinning,and ten times simulated body fluid(10SBF) were employed to mineralize nanofibrous mats. Ballshaped hydroxyapatite( HA) was deposited on the surface of nanofibrous mats in 1. 5 h at room temperature. Human fetal osteoblasts( hFob) were seeded to investigate their proliferation and differentiation on mineralized composite nanofibrous mats. The results showed that hFob grew well on mineralized composite nanofibrous mats and alkaline phosphatase( ALP) activity of hFob on mineralized composite nanofibrous mats at 14 d was much higher than that on untreated nanofibrous mats. Moreover,the expression of osteocalcin of cells on mineralized composite nanofibrous mats was also much higher than those on untreated nanofibrous mats at 7 d and 14 d. This mineralized composite nanofibrous mats may have a great potential for bone tissue engineering.

Flame Retardant Material Based on Cellulose Scaffold Mineralized by Calcium Carbonate

Wood-based functional materials have developed rapidly.But the flammability significantly limits its further application.To improve the flame retardancy,the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold,and then alternately immersed in CaCl_(2) ethanol solution and NaHCO3 aqueous solution under vacuum.The high porosity and wettability resulting from delignification benefited the following mineralization process,changing the thermal properties of balsa wood significantly.The organic-inorganic wood composite showed abundant CaCO_(3) spherical particles under scanning electron microscopy.The peak of the heat release rate of delignified balsa-CaCO_(3) was reduced by 33%compared to the native balsa,according to the cone calorimetric characterization.The flame test demonstrated that the mineralized wood was flame retardant and selfextinguish.Additionally,the mineralized wood also displayed lower thermal conductivity.This study developed a feasible way to fabricate a lightweight,fire-retardant,self-extinguishing,and heat-insulating wood composite,providing a promising route for the valuable application of cellulosic biomass.

3D printed porous titanium filled with mineralized UV-responsive chitosan hydrogel promotes cell proliferation and osteogenesis in vitro

The modification of 3D printed porous titanium(Ti),especially for the internal pore structure,is critical and has received more attention to promoting its osteogenesis for clinical use.Ultra-violet(UV)responsive chitosan(CSMA),as an injectable filling material,was firstly incorporated into porous Ti,and then CSMA was in-situ mineralized by carbon oxide(CO_(2))diffusion(CSMA/CaCO_(3)).Their physical-chemical and biological properties were investigated in vitro.CaCO_(3) crystals within CSMA hydrogels were successfully deposited into pores of porous Ti,which exhibited favorable biocompatibility.Ti implants filled with CSMA/CaCO_(3) promoted adhesion and proliferation of bone mesenchymal stem cells(BMSCs).Moreover,Ti implant filled CSMA/CaCO_(3) hydrogels could increase alkaline phosphatase(ALP)activities,up-regulate osteopontin(OPN)and osteocalcin(OCN)expression levels,and enhance extracellular mineralization.3D printed porous Ti filled with mineralized UV-responsive chitosan hydrogel could promote proliferation and osteogenesis of BMSCs,and have great potential for the modification of porous Ti implants in bone tissue engineering.

High-strength mineralized collagen artificial bone

Mineralized collagen （MC） is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal＇s cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in v/vo implantation assay demonstrated good biocompatibility of the material, and in v/vo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load- bearing sites.

Clinical evaluations of mineralized collagen in the extraction sites preservation

The purpose of this study was to explore the different effects between biomimetic mineralized collagen(MC)and ordinary physically blended hydroxyapatite/collagen(HA/Col)composite in evaluating new bone formation and regenerated bone height in human extraction sockets.Thirty-four patients who cannot retain teeth caused by trauma or decay were randomly selected from Department of Stomatology of Dongzhimen Hospital from December 2013 to December 2014.The patients were randomly divided into two groups.After the operation of tooth extraction,17 patients were implanted with biomimetic MC(MC group),and other 17 patients were implanted with ordinary physically blended nHA/Col composite(nHA/Col group).X-ray positioning projection by auto-photographing was taken to test the distance between the lowest position and the neighboring CEJm-CEJd immediately,1 month and 3 months after the operation.The height of new bone formation of the MC group was significantly higher than the nHA/Col group.Biomimetic MC showed better clinical outcomes in the bone formation for extraction site preservation and would have broad application prospect in the field of oral and maxillofacial surgeries.

Application of PMMA bone cement composited with bone-mineralized collagen in percutaneous kyphoplasty

We investigated the feasibility of applying polymethylmethacrylate bone cement composited with biomimetic bone-mineralizsed collagen to percutaneous kyphoplasty(PKP).We performed PKP in 95 patients diagnosed with osteoporotic vertebral compression fracture.All patients had fractures of a single vertebral body,and they were divided randomly into control(group A,47 patients)and experimental(group B,48 patients)groups.Patients in group A were treated with acrylic cement,and those in group B were treated with acrylic cement composited with the bone graft material.All patients were evaluated by a visual analogue scale(VAS),Oswestry disability index(ODI),Cobb angle and anterior vertebral body height preoperatively,and 3 days and 3 months postoperatively.All patients successfully completed surgery and were followed up thereafter.The VAS score,ODI index,Cobb angle and anterior vertebral body height compression rate in both groups had significant changes(P<0.05)preoperatively,and at 3 days and 3 months postoperatively.There was no significant difference between the two groups at different times(P>0.05).The analgesic effects of bone cement composited with bone-mineralized collagen are similar to those of bone cement only.Mineralized collagen has excellent promotion prospects by inducing new bone formation and reducing the incidence of adverse reactions caused by bone cement.

Clinical evaluation following the use of mineralized collagen graft for bone defects in revision total hip arthroplasty

Revision total hip arthroplasty(THA)with massive bone loss has been a real challenge for orthopaedic surgeons.Here we describe an approach using mineralized collagen(MC)graft to reconstruct acetabulum and femur with massive bone defects.We identified 89 patients suffering acetabular or femoral bone defects after primary THA,who required revision THA for this study.During the surgery,MC was applied to reconstruct both the acetabular and femoral defects.Harris hip score was used to evaluate hip function while radiographs were taken to estimate bone formation in the defect regions.The average follow-up period was 33.662.4 months.None of the components needed re-revised.Mean Harris hip scores were 42.563.5 before operation,75.264.0 at 10th month and 95.063.6 at the final follow-up.There were no instances of deep infection,severe venous thrombosis or nerve palsy.The present study demonstrated that MC graft can serve as a promising option for revision THA with massive bone deficiency.Meanwhile,extended follow-up is needed to further prove its long-term performance.

Clinical observation of biomimetic mineralized collagen artificial bone putty for bone reconstruction of calcaneus fracture

This study investigated clinical outcomes of biomimetic mineralized collagen artificial bone putty for bone reconstruction in the treatment of calcaneus fracture.Sixty cases of calcaneal fractures surgically treated with open reduction and internal fixation in our hospital from June 2014–2015 were chosen and randomly divided into two groups,including 30 cases treated with biomimetic mineralized collagen artificial bone putty as treatment group,and 30 cases treated with autogenous ilia as control group.The average follow-up time was 17.263.0 months.The results showed that the surgery duration and postoperative drainage volume of treatment group were significantly lower than control group;there were no statistically significant differences in the fracture healing time,American Orthopaedic Foot and Ankle Society scores at 3 and 12 months after surgery,Bo¨hler’s angle,Gissane’s angle and height of calcaneus between the two groups.There were no significant differences in wound complication and reject reaction between the two groups,while significant difference in donor site complication.As a conclusion,the implantation of biomimetic mineralized collagen artificial bone putty in the open reduction of calcaneal fracture resulted in reliable effect and less complications,which is suitable for clinical applications in the treatment of bone defect in calcaneal fractures.

Efficacy of concentrated growth factors combined with mineralized collagen on quality of life and bone reconstruction of guided bone regeneration

To evaluate the clinical efficacy of concentrated growth factors(CGFs)combined with mineralized collagen(MC)in guided bone regeneration(GBR).A retrospective study involving 29 patients treated with GBR technique,which was performed either CGF and MC complexes or MC alone.Implants were inserted simultaneously and cone-beam computed tomography was taken immediately,at 3 and 6 months postoperation.Questionnaires were completed by all patients so as to evaluate the main symptoms and daily activities during the first week after surgery.The outcomes of the two groups were statistically compared.All implants healed uneventfully.Patients in both groups suffered from different levels of discomfort for the reason of swelling,pain and chewing impairment on 1-2 days.Meanwhile,swelling of the Trial group was weaker than the Control group.When compared with the Control group,pain levels in Trial group were more rapidly reduced and patients took fewer analgesics from Day 3.Furthermore,the reconstitution mean value of the graft was thicker at 3 and 6 months in Trial group.CGFs complex with MC were beneficial to relieve the clinical symptoms,promote the peri-implant bone regeneration and shorten the healing time.

A high-strength mineralized collagen bone scaffold for large-sized cranial bone defect repair in sheep

Large-sized cranial bone defect repair presents a great challenge in the clinic.The ideal cranioplasty materials to realize the functional and cosmetic recovery of the defect must have sufficient mechanical support,excellent biocompatibility,good osseointegration and biodegradability as well.In this study,a high-strength mineralized collagen(MC)bone scaffold was developed with biomimetic composition,microstructure and mechanical properties for the repair of sheep largesized cranial bone defects in comparison with two traditional cranioplasty materials,polymethyl methacrylate and titanium mesh.The compact MC scaffold showed no distinct pore structure and therefore possessed good mechanical properties.The strength and elastic modulus of the scaffold were much higher than those of natural cancellous bone and slightly lower than those of natural compact bone.In vitro cytocompatibility evaluation revealed that the human bone marrow mesenchymal stem cells(hBMSC)had good viability,attachment and proliferation on the compact MC scaffold indicating its excellent biocompatibility.An adult sheep cranial bone defect model was constructed to evaluate the performances of these cranioplasty materials in repairing the cranial bone defects.The results were investigated by gross observation,computed tomography scanning as well as histological assessments.The in vivo evaluations indicated that compact MC scaffold showed notable osteoconductivity and osseointegration with surrounding cranial bone tissues by promoting bone regeneration.Our results suggested that the compact MC scaffold has a promising potential for large-sized cranial bone defect repair.

Poly(methyl methacrylate) bone cement composited with mineralized collagen for osteoporotic vertebral compression fractures in extremely old patients

To examine the clinical effects of a new bone cement composed of poly(methyl methacrylate)(PMMA)and mineralized collagen(MC)compared with pure PMMA bone cement in treating osteoporotic vertebral compression fractures(OVCFs)in patients aged over 80.In all,32 cases using pure PMMA bone cement and 31 cases using MC-modified PMMA(MC-PMMA)bone cement for OVCFs between June 2014 and March 2016 were screened as PMMA group and MC-PMMA group,respectively,with an average age of over 80.The operation duration,intraoperative blood loss,hospital stay,oswestry disability index(ODI),visual analogue scale(VAS),anterior vertebral height(AVH),intermediate vertebral height(IVH)and posterior vertebral height(PVH)of injured vertebrae,vertebral computed tomography value,re-fracture rate of adjacent vertebrae,correction rate of spinal kyphotic angle and wedge-shaped vertebra angle and surgical complications were compared between the two groups.In the early post-operative period,the VAS,ODI,AVH and IVH in MC-PMMA group were comparable to those in the traditional PMMA group.Moreover,the MC-PMMA group showed better effects compared with the PMMA group 12months after surgery.Thus,this new bone cement has superior clinic effects in the long term.