Filling Bone Defects Research Articles

Highly bioactive bone cement microspheres based on α-tricalcium phosphate microparticles/mesoporous bioactive glass nanoparticles: Formulation, physico-chemical characterization and in vivo bone regeneration

Calcium phosphate cement (CPC) is a self-setting, biocompatible and osteoconductive bone cement, however its use as a bone substitute is still limited owing to its low bioactivity (i.e. its slow in vivo resorption and slow new bone formation rate) which is a challenging issue to be addressed. Herein, we report for the first time highly bioactive bone cement microspheres formulated from a cement paste containing α-tricalcium phosphate microparticles (α-TCP) and mesoporous calcium silicate bioactive glass nanoparticles (mesoporous BGn) using a water-in-oil emulsion method. Indeed, bioactive microspheres possess high potential as bone defect fillers for bone regeneration. The α-TCP microparticles were prepared by a solid state synthesis at 1400 ºC while mesoporous BGn were synthesized by template-assissted ultrasound-mediated sol-gel method. The particle size distribution of as-prepared cement microspheres was in the range of 200 – 450 µm with a sphericity index in the range of 0.92 – 0.94. The surface morphology of α-TCP microspheres revealed α-TCP micoparticles with smooth surfaces whereas α-TCP/BGn microspheres unveiled nano-roughened α-TCP microparticles. The as-prepared α-TCP/BGn cement microspheres exhibited larger specific surface area ca 18.6 m2/g, sustained release of soluble silicate (SiO44-) ions (118 ppm within a week) and high protein adsorption capacity (252 mg/g). Notably, the α-TCP/BGn cement microspheres showed excellent in vitro surface bioactivity via formation of massive amounts of bone-like hydroxyapatite spherules and aggregates on their surfaces after soaking in simulated body fluid. Importantly, the in vivo implantation of as-prepared α-TCP/BGn cement microspheres in rat calvarial critical size bone defects for 6 weeks unveiled high in vivo bioactivity in terms of substantial new bone ingrowth and significant new bone formation within the bone defect as evidenced by histological analyses, X-ray radiography and micro-computed tomography evaluations.

Impression metadiaphyseal fractures of the proximal end of the leg bones and our experience

Introduction: Impression fractures of the proximal end of the tibia occupy the main place in the appearance of defor-mation of the articular surfaces. The goal is to improve the results of treatment of impression fractures of the proximal end of the shin bones, based on clarifying the volume of impression defects and filling the residual cavities. Materials and methods: The study analyzed the data of 32 patients with impression fractures of the proximal end of the tibia. The volume of the formed cavities was determined according to the program for the MSCT study (per cubic centimeter measurements). V = length *thickness *width *0.52 = cubic cm, the method by which radiation diagnostics doctors work and display the volume of the cavity in cubic centimeters. V cavity volume = cavity length *cavity thickness *cavity width *0.52 = cc / cm (0.52 is the accepted average value, standard). Results: The results were also studied according to the accepted methodology compiled by the crite-ria for evaluating the results, and they turned out to be the following in terms of the totality of the treatment performed: in 25 patients it was from 62 to 76 points, i.e. good, in 7 patients they were satis-factory, i.e. averaged 58 points, there were no unsatisfactory result. Discussion: The combined use of PRP-therapy, bone grafting or bone impregnated with platelet mass proved to be compatible in osteosynthesis of bone fragments using the Ilizarov apparatus. Conclusion: The use of modern visualization diagnostic tools determines the volume and calculations for filling bone defects.

Chronic osteomyelitis treatment with PerOssal®: a literature review

Chronic osteomyelitis is an inflammatory process in the bone followed by bone destruction caused by microorganism infection. The annual incidence of osteomyelitis is approximately 21.8 cases per 100,000 person-years in the general population. Implanting antibiotic-loaded carriers directly at the site of infection becomes a promising treatment approach. PerOssal® is an osteoconductive synthetic bone substitute for restoring and filling bone defects. PerOssal® pellets contain 51.1% nanocrystalline hydroxyapatite and 48.5% calcium sulfate. It has a role as bone material to fill bone defects caused by dead bone in chronic osteomyelitis. The porosity of PerOssal® allows a high initial antibiotic release, then decreases to ensure a local concentration of the antibiotic. PerOssal® did not show any in vitro cytotoxicity and fatal adverse event as bone material. PerOssal® is a promising antibiotic-loaded carrier for the management of chronic osteomyelitis. It demonstrates good biocompatibility with initial high antibiotic release without in vitro cytotoxicity and fatal adverse event.

RESULTS OF APPLYING X-RAY INVESTIGATION METHODS IN PATIENTS AFTER BONE DEFECT RESTORATION BY OSTEOPLASTIC MATERIALS USING CELLULAR TECHNOLOGIES

The results of applying X-ray investigation methods to confirm effectiveness of the developed osteoplastic combination including multipotent mesenchymal stromal cells of adipose tissue, which was used to fill bone defects in operated patients, have been elusidated. Participants and methods. The study was conducted at the Department of Surgical Dentistry and Maxillofacial Surgery, Bukovinian State Medical University, Chernivtsi, Ukraine. To determine the density of bone tissue, CT scanning was done for 26 patients when replacing the bone defect with «Kolapan–L» (group A), for 28 people during the augmentation with an osteoplastic combination containing multipotent mesenchymal stromal cells of adipose tissue (group B), and for 25 patients where bone defect healing occurred spontaneously (group C). The study was conducted after the surgical operations (in 3-5-day, 3-, 6-, 12-month follow up period. We have found out the patients of group B who received the preparation «Kolapan–L» to fill bone defects in combination with multipotent mesenchymal stromal cells of adipose tissue and platelet-rich plasma demonstrate completed osteoregeneratis with newly formed bone tissue without granules of osteoplastic material in 6-8 months after the surgical intervention. In the patients of group A, who received the preparation «Kolapan–L» to replace bone defect, a complete osteoregeneration was observed in small and medium defects in 6-8 months, and more pronounced outcomes (more than 2.0 mm) were seen in 12-16 months. In the patients of group C (spontaneous healing), small bone defects were observed after 9-11 months the healing, while significant defects showed no complete tissues regeneration even in 12 month period. The results have demonstrated that in 12 month period, the patients of group B have the average density of osteoregenerate equalled 1036,69±55,53 HU that is 1.5 times and 1.8 times more than those values in the group A, p<0.01, and in the group B, p<0.05, p1<0.01, respectively.

EFFICIENCY OF DIFFERENT OSTEOPLASTIC MATERIALS USE BEFORE DENTAL IMPLANTATION IN PATIENTS OF RESEARCH GROUPS

Objective – to investigate the effectiveness of bone augmentation materials based onmultipotent mesenchymal stromal cells of adipose tissue, which were used to fill bonedefects after various dental surgeries before dental implantation in patients of theresearch groups.Material and methods. Examination and treatment with dental implants were performedon 140 patients who had previously used various osteoplastic materials to increase thebone volume of the alveolar processes of the jaws during surgery. All patients were dividedinto III groups: I (main) group – 49 people (35.0%), in whom the material “Colapan–L”was used to restore the bone tissue of the alveolar processes; ІІ (main) group – 62 patients(44.29%), in whom the augmentation of bone defects was carried out with the help ofour proposed composition (“Colapan–L”+MMSC–ATT +PRP); Group III (control) – 29patients (20.71%) in whom wound healing occurred under a blood clot (spontaneous).Statistical processing of the results was performed on a personal computer using licensedprograms "Microsoft Excel" and "Statistica".Results. It was found that in patients, in whom a combination based on multipotentmesenchymal stromal cells of adipose tissue, the drug “Colapan-L” and platelet-richplasma was used to fill bone defects, peri-implant tissues were completely restored afterinsertion of dental implants. Also, the adequacy of our proposed osteoplastic compositionwas confirmed by X-ray examination: after 12 months of studies in patients of the maingroup II, the values of bone resorption in the implantation sites were 1.4 times and 1.8times lower than in patients of the main group, p1<0.01, and control group III, p2<0.01,respectively.Conclusions. The effectiveness of osteoplastic materials based on multipotentmesenchymal stromal cells of adipose tissue was confirmed by the values of the stabilitycoefficient of implants, which after 12 months of the research were probably higher thanthe reference, p<0.01, and 12.43% and 19.33% higher than in patients of the I main andIII control groups.

Multifarious bone cement and its applications in endodontics – A review

Polymethyl methacrylate (PMMA), commonly known as bone cement, is widely used in orthopaedic surgery, mainly for prosthesis fixation, stabilizing compressive vertebral fracture or filling bone defects. Bone cement is a potentially new repair material that has been investigated recently in dentistry because of its properties like low cytotoxicity, excellent biocompatibility and resistance to a moist environment. In Endodontics, bone cement can be used as a furcation repair material, retrograde filling material and in apexification. Modified bone cements are introduced by adding fillers, adhesives, antibiotics, and nanoparticles that make it well suited as an endodontic repair material. This review paper highlights the importance of bone cement and its possible applications in Endodontics.

Revision tibiotalar arthrodesis with posterior iliac autograft after failed arthroplasty: A matched comparative study with primary ankle arthrodeses

IntroductionTibiotalar arthrodeses performed after failed ankle arthroplasties are known to be complex procedures with often disappointing functional outcomes. This study reports the results of a revision technique using a posterior iliac crest autograft. HypothesesWe hypothesized that: (1) revision tibiotalar arthrodeses (RTTAs) had functional outcomes which were similar to those of a reference cohort of primary tibiotalar arthrodeses (TTAs) and that (2) the union rate was satisfactory. Materials and MethodsThis retrospective study compared 16 RTTAs performed for failed arthroplasties that caused pain and a functional disability (4 aseptic loosening, 4 massive progressive periprosthetic cysts, 5 malpositioning of implants, and 3 cases of unexplained mechanical pain) with a series of 16 primary TTAs performed for painful ankle osteoarthritis. The groups were matched at a 1:1 ratio for age, sex, side and body mass index. The preoperative workup included a physical exam, the American Orthopaedic Foot and Ankle Society (AOFAS) score, weight bearing radiographs, CT and SPECT scans. Outcomes were assessed both clinically (AOFAS score) and radiographically (X-rays and scans). The mean duration of the procedure (DP), average length of stay (LOS), fusion and complication rates, and time to union were also compared. ResultsAt the mean follow-up of 30 months (range, 12–88) for the RTTA group and 59 months (range, 23–94) for the TTA group (p=.001), the AOFAS score increased from 27 to 70.8 points (p<.001) and from 29.8 to 76.2 points (p<.001), respectively; values were similar at the last follow-up (p=.442). Both groups had similar fusion (94%) and complication rates (12%). The DP was 196.9±33.6min (range, 179–213) vs. 130±28.4min (range, 118–141) (p<.001) and the LOS was 3.8 days (range, 2–6) vs. 3.9 days (range, 2–6) (p<.445) for both groups (RTTA vs. TTA). ConclusionThis RTTA technique using a posterior iliac crest allograft for filling bone defects was validated by the quality of the functional outcomes obtained. Level of EvidenceIV; Comparative retrospective study.

Pickering emulsion as template for porous bioceramics in the perspective of bone regeneration

Calcium phosphate (CaP) based bioceramics are widely used as bone substitutes. The most encountered CaP ceramics are obtained from high temperature phases. However, their bioactivity and their association with biomolecules are limited, as well as their bioresorption in-vivo. The aim of this work is to develop biomimetic low temperature apatites ceramics with tunable porosity via biocompatible high internal phase Pickering emulsions. The biocompatible emulsions developed were stabilized by stoichiometric hydroxyapatite (HA) particles. Several parameters (mass of HA particles, oil/water weight ratio, electrolytes concentration in the aqueous phase) were investigated to define the optimized formulation conditions leading to a kinetically stable monodisperse emulsion with a minimum drop diameter of 200 µm and drops enough percolated to induce interconnected porosity. Two types of porous bioceramics were produced by low temperature processes with controlled composition and porosity, evidenced by X-ray microtomography: calcium phosphate monoliths from an apatitic gel, and silica-HA monoliths via a sol-gel process. These low temperature processes should provide bioceramics able to perform bioactivity and bio-resorption in-vivo, and could prefigure a drug or other therapeutic ions-delivery disposals for filling bone defects in maxillofacial or orthopedic surgery.

Complicated Mandible Fracture Treatment with Xenogenic Bone Graft

The problem of filling bone cavities remains relevant in maxillofacial and oral surgery. There is a large selection of osteotropic materials, of various natures, for filling bone defects of different etiologies. The aim of our research was to improve the outcome of surgical treatment in a patient with a complicated mandibular fracture, with the use of a collagenic xenograft during osteosynthesis. In this article, we share our experience of the treatment of a patient with a complicated mandibular angle fracture, in combination with a follicular cyst. The obligate steps of treatment included stabilization of the bone fragments, decreasing the risk of fracture line malposition, using titan mini-plates, and shortening the time of bone regeneration, by filling the bone defect with osteotropic material. This approach allowed us to reduce the rehabilitation period and further prosthetic treatment after 4–5 months, without additional bone grafting manipulations. Thus, the use of collagen osteotropic materials, possessing osteoconductive properties, can improve the treatment of patients with mandibular fractures.

Vaterite production and particle size and shape control using seawater as an indirect carbonation solvent

Vaterite, a type of calcium carbonate, has recently raised the potential for use as a drug delivery material and a filler for bone defects due to its high specific surface area and solubility, low specific gravity, and high porosity. However, existing methods of producing fine-particle vaterite exhibit limitations that annexed processes such as adding excessive additives or irradiating ultrasound are necessary, and mass production is impossible. We developed a simple, chemical additive-free, low-cost technology with mass production capability that can overcome problems faced in conventional vaterite production. We found that seawater is favorable for vaterite production and enables the reduction of its particle size because of its supersaturation in CaCO3, absence of magnesium, and high viscosity, and the reduced surface energy of vaterite. Using seawater as a solvent for indirect carbonation, we succeeded in producing a vaterite content of 100% containing fine particles without additives or additional processing. Spherical or elliptical vaterite was separately formed by adjusting the ionic strength of seawater. In addition, the ionic strength of seawater controlled the surface area and pore size of vaterite.

Tailored therapeutic release from polycaprolactone-silica hybrids for the treatment of osteomyelitis: antibiotic rifampicin and osteogenic silicates.

The treatment of osteomyelitis, a destructive inflammatory process caused by bacterial infections to bone tissue, is one of the most critical challenges of orthopedics and bone regenerative medicine. The standard treatment consists of intense antibiotic therapies combined with tissue surgical debridement and the application of a bone defect filler material. Unfortunately, commercially available candidates, such as gentamicin-impregnated polymethylmethacrylate cements, possess very poor pharmacokinetics (i.e., 24 hours burst release) and little to no regenerative potential. Fostered by the intrinsic limitations associated with conventional treatments, alternative osteostimulative biomaterials with local drug delivery have recently started to emerge. In this study, we propose the use of a polycaprolactone-silica sol-gel hybrid material as carrier for the delivery of rifampicin, an RNA-polymerase blocker often used to treat bone infections, and of osteostimulative silicate ions. The release of therapeutic agents from the material is dual, offering two separate and simultaneous effects, and decoupled, meaning that the kinetics of rifampicin and silicate releases are independent from each other. A series of hybrid formulations with increasing amounts of rifampicin was prepared. The antibiotic loading efficacy, as well as the release profiles of rifampicin and silicates were measured. The characterization of cell viability and differentiation of rat primary osteoblasts and antibacterial performance were also performed. Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Escherichia coli were selected due to their high occurrence in bone infections. Results confirmed that rifampicin can be successfully loaded within the hybrids without significant degradation and that it is possible to tailor the antibiotic release according to need. Once in a physiological environment, the rapid release of silicates was associated with optimal cell proliferation and the overexpression of osteoblastic differentiation. Simultaneously, rifampicin is delivered over the course of several weeks with significant inhibition of all tested strains. In particular, the materials caused a growth reduction of 7-10 orders of magnitude in Staphylococcus aureus, the major strain responsible for osteomyelitis worldwide. Our data strongly suggest that PCL/silica hybrids are a very promising candidate to develop bone fillers with superior biological performance compared to currently available options. Thanks to their unique synthesis route and their dual tailored release they can promote bone regeneration while reducing the risk of infection for several weeks upon implantation.

Клинический случай лечения кистозного образования плечевого сустава у ребенка с заполнением костного дефекта аллотрансплантатом

Cyst formations of the shoulder joint in children, if left untreated, can lead to the destruction and death of bone tissue, which can lead to complete dissection of the damaged part, raising a possibility of unsatisfactory results.We presented a clinical case of patient with diagnosis of a benign neoplasm of the upper third of the left humerus. In this article, we decided to share with the possibility of cyst excochleation, as well as bone grafting with an allograft using the Marburg system.We believe that the use of allogeneic grafts based on donor bone and cartilage for filling bone defects is an adequate experimental model for a comprehensive study of the processes and mechanisms of reparative osteogenesis. Bone allografting technologies are increasingly being used clinically and serve as an alternative to existing options for autoplastic operations. However, it should be taken into account that the multifactorial nature of the process of reparative osteogenesis itself, determined by a set of local and systemic mechanisms of its regulation, creates the prerequisites for the new methods search for optimizing bone tissue regeneration.Key words: allograft, cyst formations, reparative osteogenesis, bone graft.

Application of bioceramic materials in endodontic therapy: a brief review

Bioceramics (BCs) are materials that include vitreous ceramics, zirconia, bioactive glass, alumina, hydroxyapatite, resorbable calcium phosphate (CaP), and other materials. They have been utilized to fill bone defects, as root repair material, apical fill material, perforation sealing, endodontic sealers, and regeneration aids in dentistry. BCs have various advantages over other materials, including biocompatibility, BC nontoxicity, dimensional stability, and, most importantly, bioinertness in endodontic applications. There is a similarity of BC to hydroxyapatite in that they have an intrinsic osteoconductive action and the ability to initiate the regenerative responses in the human body. In endodontics, they can be broadly categorized into CaP, mixtures of calcium silicate and phosphates, hydroxyapatite-based, tricalcium, and calcium silicate-based. This review focuses on an overview of BCs; it furthermore provides a complete overview of individual BC material currently utilized in the fields of endodontics, as well as their features and applications.

Dual-functional porous and cisplatin-loaded polymethylmethacrylate cement for reconstruction of load-bearing bone defect kills bone tumor cells

Malignant bone tumors are usually treated by resection of tumor tissue followed by filling of the bone defect with bone graft substitutes. Polymethylmethacrylate (PMMA) cement is the most commonly used bone substitute in clinical orthopedics in view of its reliability. However, the dense nature of PMMA renders this biomaterial unsuitable for local delivery of chemotherapeutic drugs to limit the recurrence of bone tumors. Here, we introduce porosity into PMMA cement by adding carboxymethylcellulose (CMC) to facilitate such local delivery of chemotherapeutic drugs, while retaining sufficient mechanical properties for bone reconstruction in load-bearing sites. Our results show that the mechanical strength of PMMA-based cements gradually decreases with increasing CMC content. Upon incorporation of ≥3% CMC, the PMMA-based cements released up to 18% of the loaded cisplatin, in contrast to cements containing lower amounts of CMC which only released less than 2% of the cisplatin over 28 days. This release of cisplatin efficiently killed osteosarcoma cells in vitro and the fraction of dead cells increased to 91.3% at day 7, which confirms the retained chemotherapeutic activity of released cisplatin from these PMMA-based cements. Additionally, tibias filled with PMMA-based cements containing up to 3% of CMC exhibit comparable compressive strengths as compared to intact tibias. In conclusion, we demonstrate that PMMA cements can be rendered therapeutically active by introducing porosity using CMC to allow for release of cisplatin without compromising mechanical properties beyond critical levels. As such, these data suggest that our dual-functional PMMA-based cements represent a viable treatment option for filling bone defects after bone tumor resection in load-bearing sites.

Efficiency of use of bone augmentation materials based on multipotent mesenchymal stromal cells of adipose tissue before dental implantation in patients of study groups

Objective. To determine the effectiveness of bone augmentation materials based on multipotent mesenchymal stromal cells of adipose tissue, which were used to fill bone defects during dental operations before dental implantation in patients of the study groups.Materials and methods. Examination and treatment with dental implants were performed on 140 patients who had previously undergone surgery to increase the bone volume of the alveolar processes of the jaws with the use of various bone augmentation materials. All patients were divided into three groups: I (main) group – 49 people (35.0%), in whom the material “Colapan–L” was used to restore the bone tissue of the alveolar processes; II (main) group – 62 patients (44.29%), in whom the augmentation of bone defects was performed using our proposed composition: the drug “Colapan–L”, multipotent mesenchymal stromal cells of adipose tissue and platelet-rich plasma; group III (control) – 29 patients (20.71%) in whom wound healing occurred under a blood clot (spontaneous).Results. It was found that in patients in whom a combination based on multipotent mesenchymal stromal cells of adipose tissue, the drug “Colapan–L”and platelet-rich plasma was used to fill bone defects, peri-implant tissues were completely restored after dental implantation.Conclusions. The effectiveness of our proposed osteoplastic combination based on multipotent mesenchymal stromal cells of adipose tissue, the drug “Colapan–L” and platelet-rich plasma in patients was confirmed by the positive dynamics of the periodontal index PMA, Schiller–Pissarev test. The use of bone augmentation materials based on multipotent mesenchymal stromal cells of adipose tissue during dental operations improves the regenerative and reparative properties of the bone tissue of the jaws, facilitates the postoperative course and reduces the duration of inpatient treatment of patients.

Investigations on the Influence of Collagen Type on Physicochemical Properties of PVP/PVA Composites Enriched with Hydroxyapatite Developed for Biomedical Applications.

Nowadays, a great attention is directed into development of innovative multifunctional composites which may support bone tissue regeneration. This may be achieved by combining collagen and hydroxyapatite showing bioactivity, osteoconductivity and osteoinductivity with such biocompatible polymers as polyvinylpyrrolidone (PVP) and poly(vinyl alcohol) (PVA). Here PVA/PVP-based composites modified with hydroxyapatite (HAp, 10 wt.%) and collagen (30 wt.%) were obtained via UV radiation while two types of collagen were used (fish and bovine) and crosslinking agents differing in the average molecular weight. Next, their chemical structure was characterized using Fourier transform infrared (FT-IR) spectroscopy, roughness of their surfaces was determined using a stylus contact profilometer while their wettability was evaluated by a sessile drop method followed by the measurements of their surface free energy. Subsequently, swelling properties of composites were verified in simulated physiological liquids as well as the behavior of composites in these liquids by pH measurements. It was proved that collagen-modified composites showed higher swelling ability (even 25% more) compared to unmodified ones, surface roughness, biocompatibility towards simulated physiological liquids and hydrophilicity (contact angles lower than 90°). Considering physicochemical properties of developed materials and a possibility of the preparation of their various shapes and sizes, it may be concluded that developed materials showed great application potential for biomedical use, e.g., as materials filling bone defects supporting their treatments and promoting bone tissue regeneration due to the presence of hydroxyapatite with osteoinductive and osteoconductive properties.

OPTIMIZATION OF SURGICAL INTERVENTION METHODS IN THE TREATMENT OF ODONTOGENIC CYSTS OF THE UPPER JAW

Abstract: The therapy of odontogenic cysts of the upper and lower jaws, both conservative and operative, is of a complex nature – the frequency of this disease, according to the data, does not decrease. A number of researchers believe that the risk of inflammatory complications in odontogenic cysts is very high. The result of the injection of an odontogenic cyst of the upper jaw can be the occurrence of acute osteomyelitis with the development of a fistula and the outflow of purulent discharge into the maxillary sinus, which can later lead to the development of chronic odontogenic sinusitis. Studies of pus and granulations and analysis of the results obtained in most cases indicate a mixed microflora (staphylococcus, streptococcus, proteus, etc.). Also, when analyzing the literature, it was noted that the surgical treatment of odontogenic cysts localized on the upper jaw, as well as the use of osteoplastic materials for filling bone defects is very ambiguous and contradictory. The authors justify this fact by the fact that there is a high risk of relapses, in particular, after cystectomy, the probability of relapse is at least 17.8%. The usual scenario for conducting such nosologies is radical excision of odontogenic cysts of the jaws, after which a long time is needed to restore the bone defect, as well as adequate subsequent prosthetics. Based on these data, modern authors develop low-traumatic, sparing methods of surgical treatment of odontogenic cysts, especially of the upper jaw, including using endoscopic techniques. Based on the above, an urgent task for dental surgeons is to optimize the methods of surgical treatment of odontogenic cysts of the upper jaw, in particular with a decrease in the volume of the operating field.

Characterization and in vitro assessment of three-dimensional extrusion Mg-Sr codoped SiO2-complexed porous microhydroxyapatite whisker scaffolds for biomedical engineering

BackgroundLarge bone defects have always been a great challenge for orthopedic surgeons. The use of a good bone substitute obtained by bone tissue engineering (BTE) may be an effective treatment method. Artificial hydroxyapatite, a commonly used bone defect filler, is the main inorganic component of bones. Because of its high brittleness, fragility, and lack of osteogenic active elements, its application is limited. Therefore, its fragility should be reduced, its osteogenic activity should be improved, and a more suitable scaffold should be constructed.MethodsIn this study, a microhydroxyapatite whisker (mHAw) was developed, which was doped with the essential trace active elements Mg2+ and Sr2+ through a low-temperature sintering technique. After being formulated into a slurry, a bionic porous scaffold was manufactured by extrusion molding and freeze drying, and then SiO2 was used to improve the mechanical properties of the scaffold. The hydrophilicity, pore size, surface morphology, surface roughness, mechanical properties, and release rate of the osteogenic elements of the prepared scaffold were detected and analyzed. In in vitro experiments, Sprague–Dawley (SD) rat bone marrow mesenchymal stem cells (rBMSCs) were cultured on the scaffold to evaluate cytotoxicity, cell proliferation, spreading, and osteogenic differentiation.ResultsFour types of scaffolds were obtained: mHAw-SiO2 (SHA), Mg-doped mHAw-SiO2 (SMHA), Sr-doped mHAw-SiO2 (SSHA), and Mg-Sr codoped mHAw-SiO2 (SMSHA). SHA was the most hydrophilic (WCA 5°), while SMHA was the least (WCA 8°); SMHA had the smallest pore size (247.40 ± 23.66 μm), while SSHA had the largest (286.20 ± 19.04 μm); SHA had the smallest Young's modulus (122.43 ± 28.79 MPa), while SSHA had the largest (188.44 ± 47.89 MPa); and SHA had the smallest compressive strength (1.72 ± 0.29 MPa), while SMHA had the largest (2.47 ± 0.25 MPa). The osteogenic active elements Si, Mg, and Sr were evenly distributed and could be sustainably released from the scaffolds. None of the scaffolds had cytotoxicity. SMSHA had the highest supporting cell proliferation and spreading rate, and its ability to promote osteogenic differentiation of rBMSCs was also the strongest.ConclusionsThese composite porous scaffolds not only have acceptable physical and chemical properties suitable for BTE but also have higher osteogenic bioactivity and can possibly serve as potential bone repair materials.

Construction of tellurium-doped mesoporous bioactive glass nanoparticles for bone cancer therapy by promoting ROS-mediated apoptosis and antibacterial activity

The commonly used treatment methods for bone cancer include chemotherapy, surgery and radiotherapy, but there are disadvantages such as nonspecific distribution, high toxicity of chemotherapy drugs, implantable infections and low monitoring. Nanoparticles are the new development direction of nanomedicine in cancer treatment. Structural characteristics of nanoparticles make it an excellent model for targeting and penetrating cancer-induced abnormal cell growth. In this study, a kind of novel and interesting tellurium ion doped mesoporous bioactive glasses (Te-MBG) nanoparticles were successfully synthesized by a simple sol–gel method, which had uniform spherical morphology (≈ 500 nm), high surface area (> 300 m2/g) and mesopore volume (> 0.30 cm3/g). Results found that Te doping does not affect the mineralization and degradation of the MBG nanoparticles. Meanwhile, compared to the undoped MBG, Te doped MBG not merely had the ability to promote MG63 cell apoptosis to inhibit bone cancer growth by ROS-mediated, but also had significant antibacterial activity. This all depends on the concentration of Te doping. It can be seen that Te-MBG nanoparticles can not only potentially fill bone defects caused by bone cancer removal, but also induce cancer cell apoptosis by tellurium release inducing reactive oxygen species (ROS) excessive production to inhibit bone cancer formation. This study provides a feasible strategy for the development of Te-MBG nanoparticles as well as their evaluation and basic research for bone cancer therapy.

EFFECTS OF BONE AUGMENTATION MATERIALS ON PECULIARITIES OF POSTOPERATIVE PERIOD IN PATIENTS AFTER IMPACTED THIRD MOLAR EXTRACTION AND THEIR CLINICAL EFFICIENCY

The article presents a comparative analysis of the clinical effectiveness of bone augmentation materials, in particular, compositions including multipotent mesenchymal stromal cells of adipose tissue and platelet-enriched plasma, used to fill bone defects during the operation of third molars extraction. The criteria for the effectiveness of treatment at the stage of the early postoperative period in the participants included the assessment of the pain intensity, collateral oedema and hyperaemia of the oral mucosa after the surgery. The aim of the study is to determine the clinical efficiency of osteoplastic materials and to determine the feasibility of using tissue equivalents of bone tissue based on multipotent mesenchymal stromal cells of adipose tissue for healing of bone defects in patients with impacted third molars. Methods and participants. The study was conducted on the basis of the Department of Surgical Dentistry and Maxillofacial Surgery of Bukovynian State Medical University, Chernivtsi, Ukraine. Extraction of impacted third molars surgery was performed on 72 patients. After the tooth extraction, 31.94% of them underwent bone augmentation by osteoplastic material “Colapan–L” (group A); 41.67% of patients had bone augmentation with a combination of multipotent mesenchymal stromal cells of adipose tissue+”Colapan–L”+platelet-rich plasma (group B), and in the rest, 26.39% of patients, wound healing occurred under a blood clot (group C). Postoperative pain syndrome was assessed using the Numerical Rating Scale (NRS) based on patients' subjective feeling of pain. Visual assessment of the severity of collateral oedema and hyperaemia of the oral mucosa after surgery was also performed. A scoring system was used to determine the severity of collateral oedema. To assess the state of the postoperative period in patients of all study groups, a protocol was completed daily during the hospital stay period that reflected the most important data of an objective and subjective nature.&#x0D; During the procedure of morning dressings, we analyzed patients' complaints and evaluated general and local status: presence of appetite, quality of sleep, wound pain, postoperative oedema, hematoma, and hyperaemia of the oral mucosa, presence of secretions from the wound, body temperature, and type of wound healing. The study has demonstrated that at the final stage of postoperative follow-up the 89.31% of patients who received a combination of “Colapan–L” with multipotent mesenchymal stromal cells of adipose tissue and platelet-rich plasma reported no pain that is 1.2 times p1&lt;0.05 and 1.3 times p2&lt;0.05 higher than in the patients of groups A and B. Collateral oedema was absent in 98.47% of the group B patients that exceeded 1.2 times p1&lt;0.05 the number of such individuals in group A, where the bone defect was augmented with the osteoplastic material “Colapan–L”, and in 1.4 times higher, p1&lt;0.01, p1&gt;0.05 that the indicators of group B, where the healing of the bone defect developed without osteoplastic materials. The absence of hyperaemia of the oral mucosa was found in 92.37% of the patients in groups B, which was 1.3 and 1.4 times higher than the values obtained in groups A and B, p1&lt;0.05, p2&lt;0.01.