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The Journal of Clinical Endocrinology... Jun 2024
PubMed: 38920282
DOI: 10.1210/clinem/dgae438 -
Materials (Basel, Switzerland) Jun 2024The surface modification of dental implants plays an important role in establishing a successful interaction of the implant with the surrounding tissue, as the...
The surface modification of dental implants plays an important role in establishing a successful interaction of the implant with the surrounding tissue, as the bioactivity and osseointegration properties are strongly dependent on the physicochemical properties of the implant surface. A surface coating with bioactive molecules that stimulate the formation of a mineral calcium phosphate (CaP) layer has a positive effect on the bone bonding process, as biomineralization is crucial for improving the osseointegration process and rapid bone ingrowth. In this work, the spontaneous deposition of calcium phosphate on the titanium surface covered with chemically stable and covalently bound alendronate molecules was investigated using an integrated experimental and theoretical approach. The initial nucleation of CaP was investigated using quantum chemical calculations at the density functional theory (DFT) level. Negative Gibbs free energies show a spontaneous nucleation of CaP on the biomolecule-covered titanium oxide surface. The deposition of calcium and phosphate ions on the alendronate-modified titanium oxide surface is governed by Ca-phosphonate (-POH) interactions and supported by hydrogen bonding between the phosphate group of CaP and the amino group of the alendronate molecule. The morphological and structural properties of CaP deposit were investigated using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopy. This integrated experimental-theoretical study highlights the spontaneous formation of CaP on the alendronate-coated titanium surface, confirming the bioactivity ability of the alendronate coating. The results provide valuable guidance for the promising forthcoming advancements in the development of biomaterials and surface modification of dental implants.
PubMed: 38893965
DOI: 10.3390/ma17112703 -
International Journal of Molecular... May 2024Aminobisphosphonates (NBPs) are the first-choice medication for osteoporosis (OP); NBP treatment aims at increasing bone mineral density (BMD) by inhibiting the activity...
Aminobisphosphonates (NBPs) are the first-choice medication for osteoporosis (OP); NBP treatment aims at increasing bone mineral density (BMD) by inhibiting the activity of farnesyl diphosphate synthase (FDPS) enzyme in osteoclasts. Despite its efficacy, inadequate response to the drug and side effects have been reported. The A allele of the rs2297480 (A > C) SNP, found in the regulatory region of the gene, is associated with reduced gene transcription. This study evaluates the variant rs2297480 (A > C) association with OP patients' response to alendronate sodium treatment. A total of 304 OP patients and 112 controls were enrolled; patients treated with alendronate sodium for two years were classified, according to BMD variations at specific regions (lumbar spine (L1-L4), femoral neck (FN) and total hip (TH), as responders (OP-R) ( = 20) and non-responders (OP-NR) ( = 40). We observed an association of CC genotype with treatment failure ( = 0.045), followed by a BMD decrease in the regions L1-L4 (CC = -2.21% ± 2.56; = 0.026) and TH (CC = -2.06% ± 1.84; = 0.015) after two years of alendronate sodium treatment. Relative expression of the gene was also evaluated in OP-R and OP-NR patients. Higher expression of the gene was also observed in OP-NR group (FC = 1.84 ± 0.77; = 0.006) when compared to OP-R. In conclusion, the influence observed of expression and the rs2897480 variant on alendronate treatment highlights the importance of a genetic approach to improve the efficacy of treatment for primary osteoporosis.
Topics: Humans; Alendronate; Bone Density; Female; Geranyltranstransferase; Male; Osteoporosis; Aged; Treatment Failure; Middle Aged; Polymorphism, Single Nucleotide; Bone Density Conservation Agents; Genotype; Alleles; Case-Control Studies
PubMed: 38891810
DOI: 10.3390/ijms25115623 -
Biomacromolecules Jun 2024Photodynamic therapy (PDT) has the potential to cure pancreatic cancer with minimal side effects. Visible wavelengths are primarily used to activate hydrophobic...
Photodynamic therapy (PDT) has the potential to cure pancreatic cancer with minimal side effects. Visible wavelengths are primarily used to activate hydrophobic photosensitizers, but in clinical practice, these wavelengths do not sufficiently penetrate deeper localized tumor cells. In this work, NaYF:Yb,Er,Fe upconversion nanoparticles (UCNPs) were coated with polymer and labeled with -tetra(hydroxyphenyl)chlorin (mTHPC; temoporfin) to enable near-infrared light (NIR)-triggered PDT of pancreatic cancer. The coating consisted of alendronate-terminated poly[,-dimethylacrylamide--2-aminoethylacrylamide]--poly(ethylene glycol) [P(DMA-AEM)-PEG-Ale] to ensure the chemical and colloidal stability of the particles in aqueous physiological fluids, thereby also improving the therapeutic efficacy. The designed particles were well tolerated by the human pancreatic adenocarcinoma cell lines CAPAN-2, PANC-1, and PA-TU-8902. After intratumoral injection of mTHPC-conjugated polymer-coated UCNPs and subsequent exposure to 980 nm NIR light, excellent PDT efficacy was achieved in tumor-bearing mice.
PubMed: 38888278
DOI: 10.1021/acs.biomac.4c00317 -
Biomaterials Advances Jun 2024Chronic myeloid leukemia is a hematological cancer, where disease relapse and drug resistance are caused by bone-hosted-residual leukemia cells. An innovative resolution...
Chronic myeloid leukemia is a hematological cancer, where disease relapse and drug resistance are caused by bone-hosted-residual leukemia cells. An innovative resolution is bone-homing and selective-active targeting of anticancer loaded-nanovectors. Herein, ivermectin (IVM) and methyl dihydrojasmonate (MDJ)-loaded nanostructured lipid carriers (IVM-NLC) were formulated then dually decorated by lactoferrin (Lf) and alendronate (Aln) to optimize (Aln/Lf/IVM-NLC) for active-targeting and bone-homing potential, respectively. Aln/Lf/IVM-NLC (1 mg) revealed nano-size (73.67 ± 0.06 nm), low-PDI (0.43 ± 0.06), sustained-release of IVM (62.75 % at 140-h) and MDJ (78.7 % at 48-h). Aln/Lf/IVM-NLC afforded substantial antileukemic-cytotoxicity on K562-cells (4.29-fold lower IC), higher cellular uptake and nuclear fragmentation than IVM-NLC with acceptable cytocompatibility on oral-epithelial-cells (as normal cells). Aln/Lf/IVM-NLC effectively upregulated caspase-3 and BAX (4.53 and 15.9-fold higher than IVM-NLC, respectively). Bone homing studies verified higher hydroxyapatite affinity of Aln/Lf/IVM-NLC (1 mg; 22.88 ± 0.01 % at 3-h) and higher metaphyseal-binding (1.5-fold increase) than untargeted-NLC. Moreover, Aln/Lf/IVM-NLC-1 mg secured 1.35-fold higher in vivo bone localization than untargeted-NLC, with lower off-target distribution. Ex-vivo hemocompatibility and in-vivo biocompatibility of Aln/Lf/IVM-NLC (1 mg/mL) were established, with pronounced amelioration of hepatic and renal toxicity compared to higher Aln doses. The innovative Aln/Lf/IVM-NLC could serve as a promising nanovector for bone-homing, active-targeted leukemia therapy.
PubMed: 38875802
DOI: 10.1016/j.bioadv.2024.213924 -
Materials Today. Bio Jun 2024Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to the imbalance between osteogenesis and osteoclastogenesis, making osteoporotic...
Injectable and high-strength PLGA/CPC loaded ALN/MgO bone cement for bone regeneration by facilitating osteogenesis and inhibiting osteoclastogenesis in osteoporotic bone defects.
Osteoporosis (OP) can result in slower bone regeneration than the normal condition due to the imbalance between osteogenesis and osteoclastogenesis, making osteoporotic bone defects healing a significant clinical challenge. Calcium phosphate cement (CPC) is a promising bone substitute material due to its good osteoinductive activity, however, the drawbacks such as fragility, slow degradation rate and incapability to control bone loss restrict its application in osteoporotic bone defects treatment. Currently, we developed the PLGA electrospun nanofiber sheets to carry alendronate (ALN) and magnesium oxide nanoparticle (nMgO) into CPC, therefore, to obtain a high-strength bone cement (C/AM-PL/C). The C/AM-PL/C bone cement had high mechanical strength, anti-washout ability, good injection performance and drug sustained release capacity. More importantly, the C/AM-PL/C cement promoted the osteogenic differentiation of bone marrow mesenchymal stem cells and neovascularization via the release of Mg (from nMgO) and Ca (during the degradation of CPC), and inhibited osteoclastogenesis via the release of ALN . Moreover, the injection of C/AM-PL/C cement significantly improved bone healing in an OP model with femur condyle defects . Altogether, the injectable C/AM-PL/C cement could facilitate osteoporotic bone regeneration, demonstrating its capacity as a promising candidate for treatment of osteoporotic bone defects.
PubMed: 38873105
DOI: 10.1016/j.mtbio.2024.101092 -
ACS Biomaterials Science & Engineering Jun 2024Most hydrogels have poor mechanical properties, severely limiting their potential applications, and numerous approaches have been introduced to fabricate more robust and...
Most hydrogels have poor mechanical properties, severely limiting their potential applications, and numerous approaches have been introduced to fabricate more robust and durable examples. However, these systems consist of nonbiodegradable polymers which limit their application in tissue engineering. Herein, we focus on the fabrication and investigate the influence of hydrophobic segments on ionic cross-linking properties for the construction of a tough, biodegradable hydrogel. A biodegradable, poly(γ-glutamic acid) polymer conjugated with a hydrophobic amino acid, l-phenylalanine ethyl ester (Phe), together with an ionic cross-linking group, alendronic acid (Aln) resulting in γ-PGA-Aln-Phe, was initially synthesized. Rheological assessments through time sweep oscillation testing revealed that the presence of hydrophobic domains accelerated gelation. Comparing gels with and without hydrophobic domains, the compressive strength of γ-PGA-Aln-Phe was found to be six times higher and exhibited longer stability properties in ethylenediaminetetraacetic acid solution, lasting for up to a month. Significantly, the contribution of the hydrophobic domains to the mechanical strength and stability of ionic cross-linking properties of the gel was found to be the dominant factor for the fabrication of a tough hydrogel. As a result, this study provides a new strategy for mechanical enhancement and preserves ionic cross-linked sites by the addition of hydrophobic domains. The development of tough, biodegradable hydrogels reported herein will open up new possibilities for applications in the field of biomaterials.
PubMed: 38865608
DOI: 10.1021/acsbiomaterials.4c00681 -
Osteoporosis treatment prevents hip fracture similarly in both sexes: the FOCUS observational study.Journal of Bone and Mineral Research :... Jun 2024Randomized trials have not been performed, and may never be, to determine if osteoporosis treatment prevents hip fracture in men. Addressing that evidence gap, we...
Randomized trials have not been performed, and may never be, to determine if osteoporosis treatment prevents hip fracture in men. Addressing that evidence gap, we analyzed data from an observational study of new hip fractures in a large integrated healthcare system to compare the reduction in hip fractures associated with standard-of-care osteoporosis treatment in men versus women. Sampling from 271 389 patients age ≥ 65 who had a hip-containing computed tomography scan during care between 2005-2018, we selected all who subsequently had a first hip fracture (cases) after the CT scan (start of observation) and a sex-matched equal number of randomly selected patients. From those, we analyzed all who tested positive for osteoporosis (DXA-equivalent hip bone mineral density T-score ≤ -2.5, measured from the CT scan using VirtuOst). We defined "treated" as at least six months of any osteoporosis medication by prescription fill data during follow up; "not-treated" was no prescription fill. Sex-specific odds ratios of hip fracture for treated versus not-treated patients were calculated by logistic regression; adjustments included age, BMD T-score, a BMD-treatment interaction, body mass index, race/ethnicity, and seven baseline clinical risk factors. At two-year follow-up, 33.9% of the women (750/2211 patients) and 24.0% of the men (175/728 patients) were treated, primarily with alendronate; 51.3% and 66.3%, respectively, were not-treated; and 721 and 269, respectively, had a first hip fracture since the CT scan. Odds ratio of hip fracture for treated versus not-treated was 0.26 (95% confidence interval: 0.21-0.33) for women and 0.21 (0.13-0.34) for men; the ratio of these odds ratios (men:women) was 0.81 (0.47-1.37), indicating no significant sex effect. Various sensitivity and stratified analyses confirmed these trends, including results at five-year follow-up. Given these results and considering the relevant literature, we conclude that osteoporosis treatment prevents hip fracture similarly in both sexes.
PubMed: 38861422
DOI: 10.1093/jbmr/zjae090 -
Bioactive Materials Sep 2024Osteoporosis is majorly caused by an imbalance between osteoclastic and osteogenic niches. Despite the development of nationally recognized first-line anti-osteoporosis...
Osteoporosis is majorly caused by an imbalance between osteoclastic and osteogenic niches. Despite the development of nationally recognized first-line anti-osteoporosis drugs, including alendronate (AL), their low bioavailability, poor uptake rate, and dose-related side effects present significant challenges in treatment. This calls for an urgent need for more effective bone-affinity drug delivery systems. In this study, we produced hybrid structures with bioactive components and stable fluffy topological morphology by cross-linking calcium and phosphorus precursors based on mesoporous silica to fabricate nanoadjuvants for AL delivery. The subsequent grafting of -PEG-DAsp ensured superior biocompatibility and bone targeting capacity. RNA sequencing revealed that these fluffy nanoadjuvants effectively activated adhesion pathways through CARD11 and CD34 molecular mechanisms, hence promoting cellular uptake and intracellular delivery of AL. Experiments showed that small-dose AL nanoadjuvants effectively suppress osteoclast formation and potentially promote osteogenesis. results restored the balance between osteogenic and osteoclastic niches against osteoporosis as well as the consequent significant recovery of bone mass. Therefore, this study constructed a drug nanoadjuvant with peculiar topological structures and high bone targeting capacities, efficient intracellular drug delivery as well as bone bioactivity. This provides a novel perspective on drug delivery for osteoporosis and treatment strategies for other bone diseases.
PubMed: 38846529
DOI: 10.1016/j.bioactmat.2024.05.037 -
International Journal of Biological... Jun 2024Novel hydrogel-based multifunctional systems prepared utilizing photocrosslinking and freeze-drying processes (PhotoCross/Freeze-dried) dedicated for bone tissue...
Novel hydrogel-based multifunctional systems prepared utilizing photocrosslinking and freeze-drying processes (PhotoCross/Freeze-dried) dedicated for bone tissue regeneration are presented. Fabricated materials, composed of methacrylated gelatin, chitosan, and chondroitin sulfate, possess interesting features including bioactivity, biocompatibility, as well as antibacterial activity. Importantly, their degradation and swellability might be easily tuned by playing with the biopolymeric content in the photocrosllinked systems. To broaden the potential application and deliver the therapeutic features, mesoporous silica particles functionalized with methacrylate moieties decorated with hydroxyapatite and loaded with the antiosteoporotic drug, alendronate, (MSP-MA-HAp-ALN) were dispersed within the biopolymeric sol and photocrosslinked. It was demonstrated that the obtained composites are characterized by a significantly extended degradation time, ensuring optimal conditions for balancing hybrids removal with the deposition of fresh bone. We have shown that attachment of MSP-MA-HAp-ALN to the polymeric matrix minimizes the initial burst effect and provides a prolonged release of ALN (up to 22 days). Moreover, the biological evaluation in vitro suggested the capability of the resulted systems to promote bone remodeling. Developed materials might potentially serve as scaffolds that after implantation will fill up bone defects of various origin (osteoporosis, tumour resection, accidents) providing the favourable conditions for bone regeneration and supporting the infections' treatment.
Topics: Chondroitin Sulfates; Chitosan; Gelatin; Bone Regeneration; Biocompatible Materials; Tissue Scaffolds; Humans; Cross-Linking Reagents; Animals; Bone and Bones; Anti-Bacterial Agents; Hydrogels
PubMed: 38845259
DOI: 10.1016/j.ijbiomac.2024.132675