Rabbit Femoral Condyle Research Articles

Evaluation of injectable strontium-containing borate bioactive glass cement with enhanced osteogenic capacity in a critical-sized rabbit femoral condyle defect model.

The development of a new generation of injectable bone cements that are bioactive and have enhanced osteogenic capacity for rapid osseointegration is receiving considerable interest. In this study, a novel injectable cement (designated Sr-BBG) composed of strontium-doped borate bioactive glass particles and a chitosan-based bonding phase was prepared and evaluated in vitro and in vivo. The bioactive glass provided the benefits of bioactivity, conversion to hydroxyapatite, and the ability to stimulate osteogenesis, while the chitosan provided a cohesive biocompatible and biodegradable bonding phase. The Sr-BBG cement showed the ability to set in situ (initial setting time = 11.6 ± 1.2 min) and a compressive strength of 19 ± 1 MPa. The Sr-BBG cement enhanced the proliferation and osteogenic differentiation of human bone marrow-derived mesenchymal stem cells in vitro when compared to a similar cement (BBG) composed of chitosan-bonded borate bioactive glass particles without Sr. Microcomputed tomography and histology of critical-sized rabbit femoral condyle defects implanted with the cements showed the osteogenic capacity of the Sr-BBG cement. New bone was observed at different distances from the Sr-BBG implants within eight weeks. The bone-implant contact index was significantly higher for the Sr-BBG implant than it was for the BBG implant. Together, the results indicate that this Sr-BBG cement is a promising implant for healing irregularly shaped bone defects using minimally invasive surgery.

Effects of particle size and porosity on in vivo remodeling of settable allograft bone/polymer composites.

Established clinical approaches to treat bone voids include the implantation of autograft or allograft bone, ceramics, and other bone void fillers (BVFs). Composites prepared from lysine-derived polyurethanes and allograft bone can be injected as a reactive liquid and set to yield BVFs with mechanical strength comparable to trabecular bone. In this study, we investigated the effects of porosity, allograft particle size, and matrix mineralization on remodeling of injectable and settable allograft/polymer composites in a rabbit femoral condyle plug defect model. Both low viscosity and high viscosity grafts incorporating small (<105 μm) particles only partially healed at 12 weeks, and the addition of 10% demineralized bone matrix did not enhance healing. In contrast, composite grafts with large (105-500 μm) allograft particles healed at 12 weeks postimplantation, as evidenced by radial μCT and histomorphometric analysis. This study highlights particle size and surface connectivity as influential parameters regulating the remodeling of composite bone scaffolds.

Nanomechanical mapping of bone tissue regenerated by magnetic scaffolds.

Nanoindentation can provide new insights on the maturity stage of regenerating bone. The aim of the present study was the evaluation of the nanomechanical properties of newly-formed bone tissue at 4 weeks from the implantation of permanent magnets and magnetic scaffolds in the trabecular bone of rabbit femoral condyles. Three different groups have been investigated: MAG-A (NdFeB magnet + apatite/collagen scaffold with magnetic nanoparticles directly nucleated on the collagen fibers during scaffold synthesis); MAG-B (NdFeB magnet + apatite/collagen scaffold later infiltrated with magnetic nanoparticles) and MAG (NdFeB magnet). The mechanical properties of different-maturity bone tissues, i.e. newly-formed immature, newly-formed mature and native trabecular bone have been evaluated for the three groups. Contingent correlations between elastic modulus and hardness of immature, mature and native bone have been examined and discussed, as well as the efficacy of the adopted regeneration method in terms of "mechanical gap" between newly-formed and native bone tissue. The results showed that MAG-B group provided regenerated bone tissue with mechanical properties closer to that of native bone compared to MAG-A or MAG groups after 4 weeks from implantation. Further, whereas the mechanical properties of newly-formed immature and mature bone were found to be fairly good correlated, no correlation was detected between immature or mature bone and native bone. The reported results evidence the efficacy of nanoindentation tests for the investigation of the maturity of newly-formed bone not accessible through conventional analyses.

SrO- and MgO-doped microwave sintered 3D printed tricalcium phosphate scaffolds: mechanical properties and in vivo osteogenesis in a rabbit model.

The presence of interconnected macro pores allows guided tissue regeneration in tissue engineering scaffolds. However, highly porous scaffolds suffer from having poor mechanical strength. Previously, we showed that microwave sintering could successfully be used to improve mechanical strength of macro porous tricalcium phosphate (TCP) scaffolds. This study reports the presence of SrO and MgO as dopants in TCP scaffolds improves mechanical and in vivo biological performance. We have used direct three dimensional printing (3DP) technology for scaffold fabrication. These 3DP scaffolds possessed multiscale porosity, that is, 3D interconnected designed macro pores along with intrinsic micro pores. A significant increase in mechanical strength, between 37 and 41%, was achieved due to SrO and MgO doping in TCP as compared with pure TCP. Maximum compressive strengths of 9.38 ± 1.86 MPa and 12.01 ± 1.56 MPa were achieved by conventional and microwave sintering, respectively, for SrO-MgO-doped 3DP scaffolds with 500 μm designed pores. Histomorphological and histomorphometric analysis revealed a significantly higher osteoid, bone and haversian canal formation induced by the presence of SrO and MgO dopants in 3DP TCP as compared with pure TCP scaffolds when tested in rabbit femoral condyle defect model. Increased osteon and thus enhanced network of blood vessel formation, and osteocalcin expression were observed in the doped TCP scaffolds. Our results show that these 3DP SrO-MgO-doped TCP scaffolds have the potential for early wound healing through accelerated osteogenesis and vasculogenesis.

The effect of compressive loading magnitude on in situ chondrocyte calcium signaling.

Chondrocyte metabolism is stimulated by deformation and is associated with structural changes in the cartilage extracellular matrix (ECM), suggesting that these cells are involved in maintaining tissue health and integrity. Calcium signaling is an initial step in chondrocyte mechanotransduction that has been linked to many cellular processes. Previous studies using isolated chondrocytes proposed loading magnitude as an important factor regulating this response. However, calcium signaling in the intact cartilage differs compared to isolated cells. The purpose of this study was to investigate the effect of loading magnitude on chondrocyte calcium signaling in intact cartilage. We hypothesized that the percentage of cells exhibiting at least one calcium signal increases with increasing load. Fully intact rabbit femoral condyle and patellar bone/cartilage samples were incubated in calcium-sensitive dyes and imaged continuously under compressive loads of 10–40 % strain. Calcium signaling was primarily associated with the dynamic loading phase and greatly increased beyond a threshold deformation of about 10 % nominal tissue strain. There was a trend toward more cells exhibiting calcium signaling as loading magnitude increased (p = 0.133). These results provide novel information toward identifying mechanisms underlying calcium-dependent signaling pathways related to cartilage homeostasis and possibly the onset and progression of osteoarthritis.

Development of a novel calcium phosphate cement composed mainly of calcium sodium phosphate with high osteoconductivity

Two novel calcium phosphate cements (CPC) have been developed using calcium sodium phosphate (CSP) as the main ingredient. The first of these cements, labeled CAC, contained CSP, α-tricalcium phosphate (TCP), and anhydrous citric acid, whereas the second, labeled CABC, contained CSP, α-TCP, β-TCP, and anhydrous citric acid. Biopex(®)-R (PENTAX, Tokyo, Japan), which is a commercially available CPC (Com-CPC), and OSferion(®) (Olympus Terumo Biomaterials Corp., Tokyo, Japan), which is a commercially available porous β-TCP, were used as reference controls for analysis. In vitro analysis showed that CABC set in 5.7 ± 0.3 min at 22 °C and had a compressive strength of 86.0 ± 9.7 MPa after 5 days. Furthermore, this material had a compressive strength of 26.7 ± 3.7 MPa after 2 h in physiologic saline. CAC showed a statistically significantly lower compressive strength in the presence of physiologic saline and statistically significantly longer setting times than those of CABC. CABC and CAC exhibited apatite-forming abilities in simulated body fluid that were faster than that of Com-CPC. Samples of the materials were implanted into the femoral condyles of rabbits for in vivo analysis, and subsequent histological examinations revealed that CABC exhibited superior osteoconductivity and equivalent bioresorbability compared with Com-CPC, as well as superior osteoconductivity and bioresorbability compared with CAC. CABC could therefore be used as an alternative bone substitute material.

Shape and Site Dependent in Vivo Degradation of Mg-Zn Pins in Rabbit Femoral Condyle

A type of specially designed pin model of Mg-Zn alloy was implanted into the full thickness of lesions of New Zealand rabbits’ femoral condyles. The recovery progress, outer surface healing and in vivo degradation were characterized by various methods including radiographs, Micro-CT scan with surface rendering, SEM (scanning electron microscope) with EDX (Energy Dispersive X-ray analysis) and so on. The in vivo results suggested that a few but not sufficient bridges for holding force were formed between the bone and the implant if there was a preexisting gap between them. The rapid degradation of the implantation in the condyle would result in the appearance of cavities. Morphological evaluation of the specially designed pins indicated that the cusp was the most vulnerable part during degradation. Furthermore, different implantation sites with distinct components and biological functions can lead to different degradation rates of Mg-Zn alloy. The rate of Mg-Zn alloy decreases in the following order: implantation into soft tissue, less trabecular bone, more trabecular bone, and cortical bone. Because of the complexities of in vivo degradation, it is necessary for the design of biomedical Mg-Zn devices to take into consideration the implantation sites used in clinics.

Bone responses to zirconia implants with a thin carbonate‐containing hydroxyapatite coating using a molecular precursor method

Thin carbonate-containing hydroxyapatite (CA) films coating partially stabilized zirconia (Y-TZP) were prepared (CA-Y-TZP) to establish a metal-free implant system. CA was coated using a molecular precursor method. The CA film was deposited on the surface of Y-TZP using a precursor solution, which was a mixture of a calcium-ethylenediaminetetraacetic acid (EDTA) complex and phosphate compounds. The deposited CA film was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy measurements. A focus ion beam system technique revealed that the thickness of the CA film was less than 1.0 µm. Biological evaluations of CA-Y-TZP were performed by immersion experiments in simulated body fluid (SBF) and implantation experiments in the tibiae and femoral condyles of rabbits. In the SBF immersion experiment, apatite deposition progressed more on CA-Y-TZP at the early stage of immersion than on Y-TZP without the CA coating. Animal experiments revealed that bone formation on CA-Y-TZP was similar with than on Y-TZP. Histomorphometrical evaluations showed a significantly higher bone-to-implant contact ratio and bone mass on CA-Y-TZP after implantation into the femoral trabecular bone of rabbits. Therefore, CA-Y-TZP appears to be applicable as a metal-free implant.

Bone formation with deproteinized bovine bone mineral or biphasic calcium phosphate in the presence of autologous platelet lysate: comparative investigation in rabbit.

Bone substitutes alone or supplemented with platelet-derived concentrates are widely used to promote bone regeneration but their potency remains controversial. The aim of this study was, therefore, to compare the regenerative potential of preparations containing autologous platelet lysate (APL) and particles of either deproteinized bovine bone mineral (DBBM) or biphasic calcium phosphate (BCP), two bone substitutes with different resorption patterns. Rabbit APL was prepared by freeze-thawing a platelet suspension. Critical-size defects in rabbit femoral condyle were filled with DBBM or DBBM+APL and BCP or BCP+APL. Rabbits were sacrificed after six weeks and newly formed bone and residual implanted material were evaluated using nondemineralized histology and histomorphometry. New bone was observed around particles of all fillers tested. In the defects filled with BCP, the newly formed bone area was greater (70%; P < 0.001) while the residual material area was lower (60%; P < 0.001) than that observed in those filled with DBBM. New bone and residual material area of defects filled with either APL+DBBM or APL+BCP were similar to those observed in those filled with the material alone. In summary, osteoconductivity and resorption of BCP were greater than those of DBBM, while APL associated with either DBBM or BCP did not have an additional benefit.

Injectable Biocomposites for Bone Healing in Rabbit Femoral Condyle Defects

A novel biomimetic bone scaffold was successfully prepared in this study, which was composed of calcium sulfate hemihydrate (CSH), collagen and nano-hydroxyapatite (nHAC). CSH/nHAC was prepared and observed with scanning electron microscope and rhBMP-2 was introduced into CSH/nHAC. The released protein content from the scaffold was detected using high performance liquid chromatography at predetermined time interval. In vivo bone formation capacity was investigated by means of implanting the scaffolds with rhBMP-2 or without rhBMP-2 respectively into a critical size defect model in the femoral condyle of rabbit. The releasing character of rhBMP-2 was that an initial burst release (37.5%) was observed in the first day, followed by a sustained release and reached 100% at the end of day 20. The CSH/nHAC showed a gradual decrease in degradation with the content of nHAC increase. The results of X-rays, Micro CT and histological observation indicated that more new bone was formed in rhBMP-2 group. The results implied that this new injectable bone scaffold should be very promising for bone repair and has a great potential in bone tissue engineering.

Balancing the Rates of New Bone Formation and Polymer Degradation Enhances Healing of Weight-Bearing Allograft/Polyurethane Composites in Rabbit Femoral Defects

There is a compelling clinical need for bone grafts with initial bone-like mechanical properties that actively remodel for repair of weight-bearing bone defects, such as fractures of the tibial plateau and vertebrae. However, there is a paucity of studies investigating remodeling of weight-bearing bone grafts in preclinical models, and consequently there is limited understanding of the mechanisms by which these grafts remodel in vivo. In this study, we investigated the effects of the rates of new bone formation, matrix resorption, and polymer degradation on healing of settable weight-bearing polyurethane/allograft composites in a rabbit femoral condyle defect model. The grafts induced progressive healing in vivo, as evidenced by an increase in new bone formation, as well as a decrease in residual allograft and polymer from 6 to 12 weeks. However, the mismatch between the rates of autocatalytic polymer degradation and zero-order (independent of time) new bone formation resulted in incomplete healing in the interior of the composite. Augmentation of the grafts with recombinant human bone morphogenetic protein-2 not only increased the rate of new bone formation, but also altered the degradation mechanism of the polymer to approximate a zero-order process. The consequent matching of the rates of new bone formation and polymer degradation resulted in more extensive healing at later time points in all regions of the graft. These observations underscore the importance of balancing the rates of new bone formation and degradation to promote healing of settable weight-bearing bone grafts that maintain bone-like strength, while actively remodeling.

Quaternised chitosan-loaded polymethylmethacrylate bone cement: Biomechanical and histological evaluations

Our previous studies have demonstrated that the quaternised chitosan-loaded polymethylmethacrylate (PMMA) is a promising new antibacterial bone cement. The aim of this study was to evaluate biomechanical properties of quaternised chitosan-loaded PMMA in vitro and interface histology between cement and bone in vivo. In this study, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) with 26% degree of substitution (referred to as 26% HACC) was loaded into PMMA bone cement at a 20% mass ratio, and the specimens of 26% HACC-loaded PMMA bone cement (PMMA–H) were prepared for compressive and bending mechanical test according to ISO 5883-2002 standard prior to and after the 4-week immersion in PBS. The chitosan-loaded PMMA bone cement (PMMA–C) at the same mass ratio, pure PMMA, and gentamicin-loaded PMMA (PMMA–G) were also prepared and tested as controls. Then each of four kinds of bone cements was implanted into the rabbit femoral condyle and the osseointegration of the cement–bone interface was evaluated after its implantation over 6 weeks. The results show that biomechanical properties of both PMMA–C and PMMA–H were reduced significantly compared with the PMMA or PMMA–C, and the elastic modulus of PMMA–H was close to that of human cancellous bone. Histological observation in animal studies indicates that there was better osseointegration at the cement–bone interface in the PMMA–H group than that in the PMMA, PMMA–G, or PMMA–C groups. More new bone formation was found around PMMA–H bone cement as compared with that in the other three groups. Our findings indicated that the biomechanical properties of PMMA–H were reduced but close to that of neighbouring bone. The PMMA–H had good biocompatibility and osseointegration potential, implying its suitability for vertebral augmentation of osteoporotic vertebral compression fractures and fixation of prosthesis in cemented joint replacement.

Solid freeform fabrication of porous calcium polyphosphate structures for bone substitute applications: In vivo studies

Porous calcium polyphosphate (CPP) structures with 30 volume percent porosity and made by solid freeform fabrication (SFF) were implanted in rabbit femoral condyle sites for 6-wk periods. Two forms of SFF implants with different stacked layer orientation were made in view of prior studies reporting on anisotropic/orthotropic mechanical properties of structures so formed. In addition, porous CPP implants of equal volume percent porosity made by conventional sintering and machining methods were prepared. Bone ingrowth and in vivo degradation of the three different implant types were compared using back-scattered scanning electron microscopy (BS-SEM) of implant samples and quantitative analysis of the images. The results indicated bone ingrowth with all samples resulting in 30-40% fill of available porosity by bone within the 6-wk period. In the 6-wk in vivo period, approximately 7-9% loss of CPP by degradation had occurred.

Bioavailability of Strontium Ions from Bioactive Glasses In Vivo: A Micro-PIXE Study of Trace Elements at the Bone Interface

Studying the local release of strontium traces in vivo is of key interest, but calls for highly sensitive techniques besides providing an excellent (micronic) spatial resolution. In this context nuclear microprobes such as the PIXE (Particle-Induced X-ray Emission) technique, appear as powerful tools of investigation. Here, the in vivo behaviour of a Sr-delivering bioactive glass has been investigated through micro-PIXE analyses in connection with histological studies. New bone formation is observed after 6 weeks of implantation in rabbit femoral condyle. Interestingly, Sr traces are detected over a large area at the site of implantation, demonstrating the efficient release of Sr osteo inductive ions from the glass and their diffusion over several ten microns through the tissues. From its inorganic composition and content in traces of interest such as Zn, neo formed bone seems of higher quality for Sr-delivering particles compared to Sr-free particles, evidencing the positive effect of Sr in vivo.

Osteoconductivity of New Sodium Calcium Phosphate Pastes

We are developing a new bone paste (CaNaP paste), consists of calcium sodium phosphate (CaNaPO4), alpha-TCP, beta-TCP and citrate. It has improved handling and mechanical property with decreased setting time. For in vivo analysis using a rabbit model, four kinds of materials (Material 1: CaNaPO4 + alpha, beta-TCP + citrate, Material 2: commercially available CaP paste, Material 3: CaNaPO4 + alpha-TCP + citrate, and Material 4: commercially available porous beta-TCP) were prepared, and they were implanted into the rabbit femoral condyles (n=8). After 4 weeks and 12 weeks, histo-morphometrical analyses were performed, and bone-material contact index, bone area in the material, bone area ratio around the material, degree of bone penetration into the material, and material absorptivity were calculated. Results showed that Material 1 (newly developed CaNaP pasted containing beta-TCP) is more osteoconductive than Material 2 and Material 3 (CaNaP paste without beta-TCP), and can be expected as an attractive alternative for the bone substitute material.

Porous calcium polyphosphate as load-bearing bone substitutes:In vivostudy

Porous calcium polyphosphate (CPP) is being investigated for fabrication of novel biodegradable bone substitutes. In this study, porous CPP implants formed by conventional CPP powder packing and using a two-step sinter/anneal process was used to form 20 and 30 vol % porous samples displaying relatively high strength. These were implanted in rabbit femoral condyle sites to study their ability for secure fixation in prepared sites through bone ingrowth. Porous implants of 20 and 30 vol % porosity and displaying compressive strengths ~80 and 35 MPa, respectively, were used. Bone ingrowth sufficient to allow secure implant fixation was observed by 6 weeks (~19% bone ingrowth per available pore space for the 30 vol % and 13% for the 20 vol % porous implants). The results of the in vivo study suggest the potential usefulness of porous CPP as biodegradable bone substitutes/augments in high load-bearing skeletal regions.

Porous surface modified bioactive bone cement for enhanced bone bonding.

BackgroundPolymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth.Materials and MethodsThe porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant–bone interface was also investigated by push-out tests.ResultsThe modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect.ConclusionsOur findings suggested a new bioactive bone cement for prosthetic fixation in total joint replacement.

Construction of tissue-engineered osteochondral composites and repair of large joint defects in rabbit

In this study, a novel three-dimensional (3D) heterogeneous/bilayered scaffold was constructed to repair large defects in rabbit joints. The scaffold includes two distinct but integrated layers corresponding to the cartilage and bone components. The upper layer consists of gelatin, chondroitin sulphate and sodium hyaluronate (GCH), and the lower layer consists of gelatin and ceramic bovine bone (GCBB). The two form a 3D bilayered scaffold (GCH-GCBB), which mimics the natural osteochondral matrix for use as a scaffold for osteochondral tissue engineering. The purpose of this study was to evaluate the efficacy of this novel scaffold, combined with chondrocytes and bone marrow stem cells (BMSCs) to repair large defects in rabbit joints. Thirty-six large defects in rabbit femoral condyles were created; 12 defects were treated with the same scaffold combined with cells (group A); another 12 defects were treated with cell-free scaffolds (group B); the others were untreated (group C). At 6 and 12 weeks, in group A hyaline-like cartilage formation could be observed by histological examination; the newly formed cartilage, which stained for type II collagen, was detected by RT-PCR at high-level expression. Most of the GCBB was replaced by bone, while little remained in the underlying cartilage. At 36 weeks, GCBB was completely resorbed and a tidemark was observed in some areas. In contrast, groups B and C showed no cartilage formation but a great amount of fibrous tissue, with only a little bone formation. In summary, this study demonstrated that a novel scaffold, comprising a top layer of GCH, having mechanical properties comparable to native cartilage, and a bottom layer composed of GCBB, could be used to repair large osteochondral defects in joints.

Minocycline reduces articular cartilage damage following osteochondral injury

IntroductionSecondary injury pathways activated after chondral and osteochondral injury represent a potential target for therapies designed to minimize articular cartilage loss. The primary objective of this study was to test the potential chondroprotective effects of intra-articular minocycline following osteochondral injury. MethodsIn vitro experiments were first performed with rabbit femoral condyles explants using an osteochondral drill injury model. Data from these in vitro experiments showed that minocycline at concentrations of 10–1000nM decreased chondrocyte apoptosis in a dose-dependent manner. In vivo experiments were then conducted using the same injury model, studying the effects of intra-articular minocycline on chondrocyte apoptosis, chondrocyte cell number, and cartilage thickness. ResultsFour days after injury, minocycline delivered daily directly into the rabbit knee joints decreased acute chondrocyte apoptosis by 56% compared to controls. Analysis performed six weeks after injury demonstrated superior chondrocyte cell number, cartilage thickness, and cartilage repair in animals receiving short-term (one-week) minocycline treatment compared to controls. ConclusionsThese data support a therapeutic approach utilizing drugs like minocycline for the acute treatment of osteochondral injuries.

Osseointegration of porous titanium modified by diamond-like carbon and carbon nitride

High-porous implants capable of osteointegration are currently of great interest. Osseointegration is the establishment of bond strength between implant and host bone due to bone ingrowth into the porous structure. Ingrowth of bone tissue requires open interconnected pores and biocompatible surface, which is in direct contact with host tissues. Implants for orthopedics must have in addition a sufficient mechanical strength. In this work for in vivo experiments, cylindrical implants of 4.5mm diameter made of porous titanium (PTi) produced by the original technology were used. To improve osseointegration, on the implant surface the diamond-like carbon (DLC) or nitrogen-containing carbon (CN0.25) films were deposited using PVD technique. The PTi, PTi (DLC) and PTi (CN0.25) implants saturated by adhesion fraction of autologous bone marrow were implanted in rabbit right tibia and femoral condyles. Tensile strength study of native compact bone (σNB) and neogenic bone tissue (σBTS) at the implant–host bone interface showed the following: after 4weeks (σBTS/σNB)=0.39, 0.57 and 0.52, at 16weeks (σBTS/σNB)=0.46, 0.70 and 0.58 for PTi, PTi (DLC) and PTi (CN0.25), respectively. In all cases after 52weeks the neogenic bone tissue strength at the interface did not differ from the native bone strength. Histological studies of tissue formed in the implant pores, showed that after 4weeks a bone tissue of varying maturity was formed in the entire volume of implants: on the periphery of the implant it found bone trabecules ingrown from parent bed, and closer to the implant center a spongy immature bone tissue. In 16weeks the integration of parent bed bone and newly formed bone trabecules was determined. This process was most inhered to PTi (DLC). After 52weeks bone tissue integrated a 2/3 PTi (DLC) and 1/3 PTi (CN0.25) diameter of the implant. Our studies showed that all implants are biocompatible and osseointegrate with the native host bone. The porous titanium with DLC is the most effective and can be recommended for use in clinical trial.