-
1.
Surface Stability and Morphology of Calcium Phosphate Tuned by pH Values and Lactic Acid Additives: Theoretical and Experimental Study.
Chen, H, Lv, C, Guo, L, Ma, M, Li, X, Lan, Z, Huo, J, Dong, H, Zhu, X, Zhu, Q, et al
ACS applied materials & interfaces. 2022;(4):4836-4851
Abstract
The ubiquitous mineralization of calcium phosphate (CaP) facilitates biological organisms to produce hierarchically structured minerals. The coordination number and strength of Ca2+ ions with phosphate species, oxygen-containing additives, and solvent molecules played a crucial role in tuning nucleation processes and the surface stability of CaP under the simulated body fluid (SBF) or aqueous solutions upon the addition of oligomeric lactic acid (LACn, n = 1, 8) and changing pH values. As revealed by ab initio molecular dynamics (AIMD), density functional theory (DFT), and molecular dynamics (MD) simulations as well as high-throughput experimentation (HTE), the binding of LAC molecules with Ca2+ ions and phosphate species could stabilize both the pre-nucleation clusters and brushite (DCPD, CaHPO4·2H2O) surface through intermolecular electrostatic and hydrogen bonding interactions. When the concentration of Ca2+ ions ([Ca2+]) is very low, the amount of the formed precipitation decreased with the addition of LAC based on UV-vis spectroscopic analysis due to the reduced chance for the LAC capped Ca2+ ions to coordinate with phosphates and the increased solubility in the acid solution. With the increasing [Ca2+] concentration, the kinetically stable DCPD precipitation was obtained with high Ca2+ coordination number and low surface energy. Morphologies of DCPD precipitation are in plate, needle, or rod, depending on the initial pH values that were tuned by adding NH3·H2O, HCl, or CH3COOH. The prepared samples at pH ≈ 7.4 with different Ca/P ratios exhibited negative zeta potential values, which were correlated with the surface electrostatic potential distributions and potential biological applications.
-
2.
Glycophosphopeptical AM3 Food Supplement: A Potential Adjuvant in the Treatment and Vaccination of SARS-CoV-2.
Fernández-Lázaro, D, Fernandez-Lazaro, CI, Mielgo-Ayuso, J, Adams, DP, García Hernández, JL, González-Bernal, J, González-Gross, M
Frontiers in immunology. 2021;:698672
Abstract
The world is currently experiencing the coronavirus disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome-2 (SARS-CoV-2). Its global spread has resulted in millions of confirmed infections and deaths. While the global pandemic continues to grow, the availability of drugs to treat COVID-19 infections remains limited to supportive treatments. Moreover, the current speed of vaccination campaigns in many countries has been slow. Natural substrates with biological immunomodulatory activity, such as glucans, may represent an adjuvant therapeutic agent to treat SARS-CoV-2. AM3, a natural glycophosphopeptical, has previously been shown to effectively slow, with no side effects, the progression of infectious respiratory diseases by regulating effects on innate and adaptive immunity in experimental models. No clinical studies, however, exist on the use of AM3 in SARS-CoV-2 infected patients. This review aims to summarize the beneficial effects of AM3 on respiratory diseases, the inflammatory response, modulation of immune response, and attenuation of muscle. It will also discuss its potential effects as an immune system adjuvant for the treatment of COVID-19 infections and adjuvant for SARS-CoV-2 vaccination.
-
3.
The surgical management of the cavity and bone defects in enchondroma cases: A prospective randomized trial.
Nazarova, NZ, Umarova, GS, Vaiman, M, Asilova, SU, Abba, M, Foonberg, M, Shterenshis, M
Surgical oncology. 2021;:101565
Abstract
BACKGROUND We compared the curettage/bone grafting and the curettage/bone graft substitutes surgical techniques in their relation to functional outcomes, oncologic outcome (recurrence, malignant transformation), the rate of postsurgical complications, durations of surgery and of postsurgical immobilization for hand-localized cases of solitary and multiple enchondromas. METHODS The current prospective randomized trial analyzed 200 adult patients (2012-2017) with enchondroma who underwent surgical intervention. The cases were randomly divided into Group 1 (n = 100; F 56, M 44) for surgeries with curettage and autogenous bone grafting, and Group 2 (n = 100; F 55, M 45) for surgeries with curettage and bone graft substitutes. The placebo control Group 3 consisted of cases operated by curettage only (n = 56; F 31, M 25). The follow-up period was set at 30 months. RESULTS The duration of surgery was 51 ± 4 min in Group 1 and 27 ± 1 min in Group 2 (p = 0.008). In Group 1, the rate of recurrence was 6% against 1% in Group 2 (p = 0.005). No other statistically significant differences in postsurgical outcomes between three involved groups were noted. CONCLUSION In cases of enchondroma of the hand, postsurgical functional outcomes, the rate of postsurgical complications, the duration of immobilization, and the time to complete recovery are not influenced by the type of chosen grafting material. The implementation of HAp-collagen bone substitutes in granules instead of autogenous bone grafting reduces the duration of surgery. The implementation of autogenous bone grafting may increase the rate of tumor recurrence.
-
4.
The effect of increasing dialysate magnesium on calciprotein particles, inflammation and bone markers: post hoc analysis from a randomized controlled clinical trial.
Bressendorff, I, Hansen, D, Pasch, A, Holt, SG, Schou, M, Brandi, L, Smith, ER
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 2021;(4):713-721
Abstract
BACKGROUND The formation of calciprotein particles (CPPs) may be an important component of the humoral defences against ectopic calcification. Although magnesium (Mg) has been shown to delay the transition of amorphous calcium-/phosphate-containing primary CPP (CPP-1) to crystalline apatite-containing secondary CPP (CPP-2) ex vivo, effects on the endogenous CPP pool are unknown. METHODS We used post hoc analyses from a randomized double-blind parallel-group controlled clinical trial of 28 days treatment with high dialysate Mg of 2.0 mEq/L versus standard dialysate Mg of 1.0 mEq/L in 57 subjects undergoing maintenance hemodialysis for end-stage kidney disease. CPP load, markers of systemic inflammation and bone turnover were measured at baseline and follow-up. RESULTS After 28 days of treatment with high dialysate Mg, serum total CPP (-52%), CPP-1 (-42%) and CPP-2 (-68%) were lower in the high Mg group (all P < 0.001) but were unchanged in the standard dialysate Mg group. Tumour necrosis factor-α (-20%) and interleukin-6 (-22%) were also reduced with high dialysate Mg treatment (both P < 0.01). High dialysate Mg resulted in higher levels of bone-specific alkaline phosphatase (a marker of bone formation) (+17%) but lower levels of tartrate-resistant acid phosphatase 5 b (a marker of bone resorption; -33%) (both P < 0.01). Inflammatory cytokines and bone turnover markers were unchanged in the standard dialysate Mg group over the same period. CONCLUSIONS In this exploratory analysis, increasing dialysate Mg was associated with reduced CPP load and systemic inflammation and divergent changes in markers of bone formation and resorption.
-
5.
Recent progress in preparation and applications of chitosan/calcium phosphate composite materials.
Salama, A
International journal of biological macromolecules. 2021;:240-252
Abstract
Studying the development of unique materials from sustainable and renewable resources has gained increasing concern due to the depletion of fossil resources. Chitosan and its derivatives have been considered as versatile candidates for preparing attractive materials. The fabrication of chitosan/calcium phosphate composite compounds has received much attention for the development of numerous promising products in different fields. In this short review, recent preparation strategies for chitosan/calcium phosphate composites such as freeze casting, vacuum-assisted filtration, and biomimetic mineralization were discussed. The review presented their advances for diverse applications such as bone tissue engineering implants, drug delivery, wound healing, dental caries, as well adsorption of organic and heavy metals from polluted water. The challenges and future perspectives for the application of chitosan/calcium phosphate materials in biomedical and environmental applications were also involved in this review article.
-
6.
Study on microstructure, microhardness, bioactivity, and biocompatibility of La2 O3 -containing bioceramic coating doping SiO2 fabricated by laser cladding.
Fu, Q, Liu, Q, Li, L, Li, X, Gu, H, Sheng, B, Yang, B
Journal of biomedical materials research. Part B, Applied biomaterials. 2020;(5):2099-2107
Abstract
To solve the lack of strength of calcium phosphate ceramic coatings in load-bearing applications, gradient Ca-P bioceramic coatings doped with La2 O3 and SiO2 are fabricated by laser cladding on Ti-6Al-4 V. The effect of SiO2 on microstructure, microhardness, bioactivity, and biocompatibility of coatings was investigated. The experimental results illustrate that the coating doped with La2 O3 and SiO2 has excellent metallurgical bonding. The XRD analysis confirms that the amount of hydroxyapatite and tricalcium phosphate in the coating reached maximum when doping amount of SiO2 is 10 wt %. SiO2 -doped coatings show a significantly higher bone-like apatite precipitation after immersion in SBF than that of other coatings. in vitro experiment also shows that coating with 10 wt % SiO2 is more suitable for the attachment and proliferation of MG63 cells, indicating that coating with 10 wt % SiO2 exhibits best bioactivity and biocompatibility. These results suggest that the addition of SiO2 improves the bonding strength, bioactivity, and biocompatibility of coatings.
-
7.
Osteopontin regulates biomimetic calcium phosphate crystallization from disordered mineral layers covering apatite crystallites.
Iline-Vul, T, Nanda, R, Mateos, B, Hazan, S, Matlahov, I, Perelshtein, I, Keinan-Adamsky, K, Althoff-Ospelt, G, Konrat, R, Goobes, G
Scientific reports. 2020;(1):15722
Abstract
Details of apatite formation and development in bone below the nanometer scale remain enigmatic. Regulation of mineralization was shown to be governed by the activity of non-collagenous proteins with many bone diseases stemming from improper activity of these proteins. Apatite crystal growth inhibition or enhancement is thought to involve direct interaction of these proteins with exposed faces of apatite crystals. However, experimental evidence of the molecular binding events that occur and that allow these proteins to exert their functions are lacking. Moreover, recent high-resolution measurements of apatite crystallites in bone have shown that individual crystallites are covered by a persistent layer of amorphous calcium phosphate. It is therefore unclear whether non-collagenous proteins can interact with the faces of the mineral crystallites directly and what are the consequences of the presence of a disordered mineral layer to their functionality. In this work, the regulatory effect of recombinant osteopontin on biomimetic apatite is shown to produce platelet-shaped apatite crystallites with disordered layers coating them. The protein is also shown to regulate the content and properties of the disordered mineral phase (and sublayers within it). Through solid-state NMR atomic carbon-phosphorous distance measurements, the protein is shown to be located in the disordered phases, reaching out to interact with the surfaces of the crystals only through very few sidechains. These observations suggest that non-phosphorylated osteopontin acts as regulator of the coating mineral layers and exerts its effect on apatite crystal growth processes mostly from afar with a limited number of contact points with the crystal.
-
8.
Radiographic and clinical outcomes of silicate-substituted calcium phosphate (SiCaP) bone grafts in spinal fusion: Systematic review and meta-analysis.
Cottrill, E, Premananthan, C, Pennington, Z, Ehresman, J, Theodore, N, Sciubba, DM, Witham, T
Journal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia. 2020;:353-366
Abstract
Pseudarthrosis continues to affect a nontrivial proportion of spine fusion patients. Given its ties to poorer patient outcomes and high reoperation rates, there remains great interest in interventions aimed at reducing the rates of nonunion. Recently, silicate-substituted calcium phosphate (SiCaP) bone grafts have been suggested to improve fusion rates, yet there exists no systematic review of the body of evidence for SiCaP grafts. Here, we present the first such review along with a meta-analysis of the effect of SiCaP bone grafts on fusion rates. Using the PubMed, Embase, and Web of Science databases, we queried the English-language literature for all studies examining the effect of SiCaPs on spinal fusion. Primary endpoints were: 1) radiographic fusion rate at last follow-up and 2) postoperative improvements in Visual Analog Scale (VAS) pain scores and Oswestry Disability Index (ODI) at last follow-up. Meta-analyses were performed for each endpoint using random effects. Ten articles (694 patients treated with SiCaP bone grafts) were included. Among SiCaP-treated patients, 93% achieved radiographic fusion (range: 79-100%), with comparable rates across subgroups. Meta-analysis of the three randomized controlled trials demonstrated no difference in fusion rates between SiCaP-treated patients and patients receiving grafts with recombinant human bone morphogenetic protein-2 (rhBMP-2) (OR: 1.11; p = 0.83). Patients treated with SiCaP bone grafts experienced significant improvements in VAS back pain (-3.3 points), VAS leg pain (-4.8 points), and ODI (-31.6 points) by last follow-up (p < 0.001 for each). Additional high-quality research is needed to evaluate the relative cost-effectiveness of SiCaP bone grafts in spinal fusion.
-
9.
Effect of doping different Si source on Ca-P bioceramic coating fabricated by laser cladding.
Fu, Q, Liu, Q, Li, L, Li, X, Gu, H, Sheng, B
Journal of applied biomaterials & functional materials. 2020;:2280800020917322
Abstract
The doping of silicon (Si) has been proved to improve the bioactivity of Ca-P ceramics. In light of this thinking, in the present study, Ca-P coatings with La2O3 by addition of 10 wt% SiO2 and 10 wt% diatomaceous earth (DE) were fabricated by laser cladding on Ti6Al4V, respectively. Coating doped without Si was also fabricated as the comparison group for the experiment. The effect of two different Si sources on the surface morphology, microstructure, microhardness, and bioactivity was systematically studied. The experimental results show that the Si-doped coating is of rough surface morphology, and the addition of DE significantly reduces the number of cracks and improves the microhardness. The X-ray diffraction results reveal that the amount of bioactive phase tricalcium-phosphate (TCP) and hydroxyapatite (HA) reaches maximum in the DE-doped coating. After soaking in simulated body fluid (SBF), the precipitate of bone-like apatite in the DE-doped coating is significantly higher than that of the other coatings.
-
10.
First clinical application of octacalcium phosphate collagen composite on bone regeneration in maxillary sinus floor augmentation: A prospective, single-arm, open-label clinical trial.
Miura, KI, Sumita, Y, Kajii, F, Tanaka, H, Kamakura, S, Asahina, I
Journal of biomedical materials research. Part B, Applied biomaterials. 2020;(1):243-252
Abstract
The overall objective of this study was to assess the safety and efficacy of OCP/Col as a bone substitute material for bone regeneration during sinus floor augmentation. Maxillary sinus floor augmentation was performed thorough lateral window approach. According to the height of host bone, simultaneous approach (≥5 mm) or staged approach (less than 5 mm) was applied. In this research, clinical findings of dental implant treatment after setting the restorations were set as a primary endpoint in both approaches (infection, inflammation around the implant, movement of the implant, pain, sensory disorder, and bone resorption around the implant body on radiological evaluation.). In staged approach, histological evaluation of bone biopsy specimen was also conducted. As secondary endpoints, hounsfield unit (HU) value, vertical bone height, implant stability quotient (ISQ), and adverse events during the research were evaluated. In all cases, as a primary endpoint, clinical findings after setting the restorations were uneventful with no adverse events. Histological structure demonstrated mature bone derived from OCP/Col. In the ossified area, osteogenesis was observed around OCP granules, and osteoblast-like cells were arrayed around OCP granules. Osteocyte encapsulation was recognized in the new bone. HU increased over time with both approaches. Vertical bone height significantly increased at 3 months postoperatively, and maintained during follow-up. ISQ increased with both approaches. In particular, ISQ was significantly increased with the staged approach. This clinical trial demonstrated the safety and efficacy of OCP/Col for bone regeneration in maxillary sinus floor augmentation. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:243-252, 2020.