A 3D In-vitro model of the human dentine interface shows long-range osteoinduction from the dentine surface.

Emerging regenerative cell therapies for alveolar bone loss have begun to explore the use of cell laden hydrogels for minimally invasive surgery to treat small and spatially complex maxilla-oral defects. However, the oral cavity presents a unique and challenging environment for in vivo bone tissue engineering, exhibiting both hard and soft periodontal tissue as well as acting as key biocenosis for many distinct microbial communities that interact with both the external environment and internal body systems, which will impact on cell fate and subsequent treatment efficacy. Herein, we design and bioprint a facile 3D in vitro model of a human dentine interface to probe the effect of the dentine surface on human mesenchymal stem cells (hMSCs) encapsulated in a microporous hydrogel bioink. We demonstrate that the dentine substrate induces osteogenic differentiation of encapsulated hMSCs, and that both dentine and ß-tricalcium phosphate substrates stimulate extracellular matrix production and maturation at the gel-media interface, which is distal to the gel-substrate interface. Our findings demonstrate the potential for long-range effects on stem cells by mineralized surfaces during bone tissue engineering and provide a framework for the rapid development of 3D dentine-bone interface models.

Ca(H2PO4)2 and MgSO4 activated nitrogen-related bacteria and genes in thermophilic stage of compost.

This study was conducted to investigate the effects of Ca(H2PO4)2 and MgSO4 on the bacterial community and nitrogen metabolism genes in the aerobic composting of pig manure. The experimental treatments were set up as control (C), 1% Ca(H2PO4)2 + 2% MgSO4 (CaPM1), and 1.5% Ca(H2PO4)2 + 3% MgSO4 (CaPM2), which were used at the end of composting for potting trials. The results showed that Ca(H2PO4)2 and MgSO4 played an excellent role in retaining nitrogen and increasing the alkali-hydrolyzed nitrogen (AN), available phosphorus (AP), and available potassium (AK) contents of the composts. Adding Ca(H2PO4)2 and MgSO4 changed the microbial community structure of the compost. The microorganisms associated with nitrogen retention were activated. The complexity of the microbial network was enhanced. Genetic prediction analysis showed that the addition of Ca(H2PO4)2 and MgSO4 reduced the accumulation of nitroso-nitrogen and the process of denitrification. At the same time, despite the reduction of genes related to nitrogen fixation, the conversion of ammonia to nitrogenous organic compounds was promoted and the stability of nitrogen was increased. Mantel test analysis showed that Ca(H2PO4)2 and MgSO4 can affect nitrogen transformation-related bacteria and thus indirectly affect nitrogen metabolism genes by influencing the temperature, pH, and organic matter (OM) of the compost and also directly affected nitrogen metabolism genes through PO43- and Mg2+. The pot experiment showed that composting with 1.5% Ca(H2PO4)2 + 3% MgSO4 produced the compost product that improved the growth yield and nutrient content of cilantro and increased the fertility of the soil. In conclusion, Ca(H2PO4)2 and MgSO4 reduces the loss of nitrogen from compost, activates nitrogen-related bacteria and genes in the thermophilic phase of composting, and improves the fertilizer efficiency of compost products. KEY POINTS: • Ca(H2PO4)2 and MgSO4 reduced the nitrogen loss and improved the compost effect • Activated nitrogen-related bacteria and altered nitrogen metabolism genes • Improved the yield and quality of cilantro and fertility of soil.

Kidney stone growth through the lens of Raman mapping.

Bulk composition of kidney stones, often analyzed with infrared spectroscopy, plays an essential role in determining the course of treatment for kidney stone disease. Though bulk analysis of kidney stones can hint at the general causes of stone formation, it is necessary to understand kidney stone microstructure to further advance potential treatments that rely on in vivo dissolution of stones rather than surgery. The utility of Raman microscopy is demonstrated for the purpose of studying kidney stone microstructure with chemical maps at ≤ 1 µm scales collected for calcium oxalate, calcium phosphate, uric acid, and struvite stones. Observed microstructures are discussed with respect to kidney stone growth and dissolution with emphasis placed on < 5 µm features that would be difficult to identify using alternative techniques including micro computed tomography. These features include thin concentric rings of calcium oxalate monohydrate within uric acid stones and increased frequency of calcium oxalate crystals within regions of elongated crystal growth in a brushite stone. We relate these observations to potential concerns of clinical significance including dissolution of uric acid by raising urine pH and the higher rates of brushite stone recurrence compared to other non-infectious kidney stones.

Time to full weight-bearing with the use of a calcium sulfate-calcium phosphate bone substitute as a bone void filler following extended curettage in the treatment of primary benign bone tumours.

PURPOSE: The primary objective of this study was to determine time to full weight-bearing after the use of a calcium-sulfate-calcium phosphate bone substitute (CaSO4/CaPO4) as a bone void filler in the treatment of primary benign bone tumours following intralesional curettage. The secondary objectives were to determine surgical complications and recurrence rates. METHODS: Retrospective review of patients identified from a surgeon-specific orthopaedic oncology database, who underwent curettage of benign bone tumours and subsequent bone void filling with CaSO4/CaPO4. RESULTS: A total of 39 patients (20 males, 19 females) met inclusion criteria with an average age of 31 years (range: 13 to 62 years), a median follow-up of 3.7 years, and a maximum follow-up of 11 years. The most common tumour diagnosis was giant cell tumour of bone (GCT) (n = 19), and the most common location was the proximal tibia (n = 9). The mean volume of tumour excised was 74.1 cm3 including extraosseous bone expansion due to tumour growth, with a mean of volume of 21.4 mL of CaSO4/CaPO4 used to fill the intraosseous cavitary defects to restore normal bone anatomy. None of the lesions required additional internal fixation. The primary outcome measure, average time to full weight-bearing/full range of motion, was 11 weeks and 6 weeks for upper and lower extremity lesions, respectively. Secondary outcomes included tumour recurrence requiring reoperation in five patients and infection requiring reoperation in two patients. CONCLUSION: This study demonstrates that CaSO4/CaPO4 is a viable option as a bone void filler in the reconstruction of cavitary defects following removal of primary benign bone tumours. CaSO4/CaPO4 provides sufficient bone regeneration early in the post-operative period to allow progression to full weight-bearing within weeks without the need for internal fixation. There were no graft-specific complications noted.

Feasibility Insights of the Green-Assisted Calcium-Phosphate Coating on Biodegradable Zinc Alloys for Biomedical Application: In Vitro and In Vivo Studies.

In the field of bone tissue engineering, recently developed Zn alloy scaffolds are considered potential candidates for biodegradable implants for bone regeneration and defect reconstruction. However, the clinical success of these alloys is limited due to their insufficient surface bioactivities. Further, the higher concentration of Zn2+ produced during degradation promotes antibacterial activity, but deteriorates osteogenic properties. This study fabricated an Azadirachta indica (neem)-assisted brushite-hydroxyapatite (HAp) coating on the recently developed Zn-2Cu-0.5Mg alloy to tackle the above dilemma. The microstructure, degradation behavior, antibacterial activity, and hemocompatibility, along with in vitro and in vivo cytocompatibility of the coated alloys, are systematically investigated. Microstructural analysis reveals flower-like morphology with uniformly grown flakes for neem-assisted deposition. The neem-assisted deposition significantly improves the adhesion strength from 12.7 to 18.8 MPa, enhancing the mechanical integrity. The potentiodynamic polarization study shows that the neem-assisted deposition decreases the degradation rate, with the lowest degradation rate of 0.027 mm/yr for the ZHN2 sample. In addition, the biomineralization process shows the apatite formation on the deposited coating after 21 days of immersion. In vitro cytotoxicity assay exhibits the maximum cell viability of 117% for neem-assisted coated alloy in 30% extract after 5d and the improved cytocompatibility which is due to the controlled release of Zn2+ ions. Meanwhile, neem-assisted coated alloy increases the ZOI by 32 and 24% for Gram-positive and Gram-negative bacteria, respectively. Acceptable hemolysis (<5%) and anticoagulation parameters demonstrate a promising hemocompatibility of the coated alloy. In vivo implantation illustrates a slight inflammatory response and vascularization after 2 weeks of subcutaneous implantation, and neo-bone formation in the defect areas of the rat femur. Micro-CT and histology studies demonstrate better osseointegration with satisfactory biosafety response for the neem-assisted coated alloy as compared to that without neem-assisted deposition. Hence, this neem-assisted brushite-Hap coating strategy elucidates a new perspective on the surface modification of biodegradable implants for the treatment of bone defects.

Study of biphasic calcium phosphate (BCP) ceramics of tilapia fish bones by age.

Biphasic calcium phosphate (BCP), consisting of bioceramics such as HAp + ß-TCP and Ca10(PO4)6(OH)2 + Ca3(PO4)2, is a popular choice for optimizing performance due to its superior biological reabsorption and osseointegration. In this study, BCP was produced by calcining the bones of tilapia fish (Oreochromis niloticus) reared in net cages and slaughtered at an age ranging from 15 to 420 days. The bones were cleaned and dried, calcined at 900 °C for 8 h, and then subjected to high-energy grinding for 3 h to produce BCP powders. After the calcination process, the crystalline phase's hydroxyapatite (HAp) and/or beta-tricalcium phosphate (ß-TCP) were present in the composition of the bioceramic. The age-dependent variation in phase composition was confirmed by complementary vibrational spectroscopy techniques, revealing characteristic peaks and bands of the bioceramic. This variation was marked by an increase in HAp phase and a decrease in ß-TCP phase. Thermogravimetric Analysis (TGA) and Differential Thermal Analysis (DTA) from 25 to 1400 °C showed the characteristic mass losses of the material, with a greater loss observed for younger fish, indicating the complete removal of organic components at temperatures above 600 °C. Comparison of the results obtained by X-Ray Diffraction (XRD) and Rietveld refinement with Raman spectroscopy showed excellent agreement. These results showed that with temperature and environment control and adequate fish feeding, it is possible to achieve the desired amounts of each phase by choosing the ideal age of the fish. This bioceramic enables precise measurement of HAp and ß-TCP concentrations and Ca/P molar ratio, suitable for medical orthopedics and dentistry.

Immobilized Dipeptidase in Manganese Ion-Loaded Polyethylenimine-Induced Calcium Phosphate Nanocrystals for Carnosine Synthesis.

Carnosine is a natural bioactive dipeptide with important physiological functions widely used in food and medicine. Dipeptidase (PepD) from Serratia marcescens can catalyze the reverse hydrolytic reaction of ß-alanine with l-histidine to synthesize carnosine in the presence of Mn2+. However, it remains challenging to practice carnosine biosynthesis due to the low activity and high cost of the enzyme. Therefore, the development of biocatalysts with high activity and stability is of significance for carnosine synthesis. Here, we proposed to chelate Mn2+ to polyethylenimine (PEI) that induced rapid formation of calcium phosphate nanocrystals (CaP), and Mn-PEI@CaP was used for PepD immobilization via electrostatic interaction. Mn-PEI@CaP as the carrier enhanced the stability of the immobilized enzyme. Moreover, Mn2+ loaded in the carrier acted as an in situ activator of the immobilized PepD for facilitating the biocatalytic process of carnosine synthesis. The as-prepared immobilized enzyme (PepD-Mn-PEI@CaP) kept similar activity with free PepD plus Mn2+ (activity recovery, 102.5%), while exhibiting elevated thermal stability and pH tolerance. Moreover, it exhibited about two times faster carnosine synthesis than the free PepD system. PepD-Mn-PEI@CaP retained 86.8% of the original activity after eight cycles of batch catalysis without the addition of free Mn2+ ions during multiple cycles. This work provides a new strategy for the co-immobilization of PepD and Mn2+, which greatly improves the operability of the biocatalysis and demonstrates the potential of the immobilized PepD system for efficient carnosine synthesis.

Composition analysis of 1,495 cases of upper urinary tract calculi: the role of age and gender.

OBJECTIVE: This study aimed to quantitatively analyze the calculi components of upper urinary tract calculi and to explore the relationship between calculus components, demographic characteristics, and underlying diseases. PATIENTS AND METHODS: Clinical data of 1,495 patients with upper urinary tract calculi were retrospectively collected. The calculi were divided into simple calcium oxalate, calcium oxalate mixed, calcium phosphate mixed, uric acid, magnesium ammonium phosphate, and other components. Statistical software SPSS 22.0 was used to analyze the differences between the stone compositions and various factors. The influencing factors (p < 0.05) were analyzed using multiple logistic regression analysis. RESULTS: Among 1,495 patients with upper urinary tract calculi, simple calcium oxalate calculi were the most common component (39.7%), followed by calcium oxalate mixed calculi (30.4%), uric acid calculi (13.6%), calcium phosphate mixed calculi (10.4%), magnesium ammonium phosphate calculi (5.8%) and other component calculi (0.1%). Univariate analysis revealed statistically significant differences in stone composition according to gender, age, and hyperuricemia (p < 0.05). Multiple logistic regression analysis showed that compared to men, the odds ratio (OR) values of calcium oxalate mixed stones, calcium phosphate mixed stones, and magnesium ammonium phosphate stones in women were 1.61, 2.50, and 4.17, respectively (p < 0.001). Compared with elderly patients, the OR values of calcium phosphate mixed stones in young and middle-aged patients were 3.14 and 2.70, respectively (p < 0.05). CONCLUSIONS: Patients with different stone components had different demographic characteristics, and stone components were significantly different between gender and age. Calcium oxalate mixed stones were more common in females, and calcium phosphate mixed stones and magnesium ammonium phosphate stones were more common in females, young patients, and middle-aged patients.

Electron Microscopy for the Stability Assessment of Parenteral Nutrition Admixtures: Focus on Precipitation.

(1) Background: parenteral nutrition (PN) is indispensable for patients unable to receive oral or enteral feeding. However, the complexity of PN solutions presents challenges regarding stability and compatibility. Precipitation reactions may occur. The most frequent is the formation of calcium phosphate (Ca-P). The different factors influencing these reactions must be considered to ensure patient safety. (2) Methods: eight paediatric PN solutions were prepared, following standard protocols. Samples were stored at room temperature and in a refrigerator. Electron microscopy, coupled with energy dispersive X-ray spectroscopy (EDS), was employed. Precipitates were analysed for composition and morphology. (3) Results: precipitates were observed in all samples, even at day 0. Crystalline structures, predominantly composed of calcium or magnesium, sometimes associated with chlorine or phosphorus, were detected. Additionally, amorphous precipitates, contained heterogeneous compositions, including unexpected elements, were identified. (4) Conclusions: various precipitates, primarily calcium- or magnesium-based, can form in PN solutions, although it is not expected that they can form under the real conditions of use. Calcium oxalate precipitation has been characterised, but the use of organic calcium and phosphate salts appears to mitigate calcium phosphate precipitation. Electron microscopy provides interesting results on NP precipitation, but sample preparation may present technical limitations that affect the interpretation of the results.

A model approach to show that monocytes can enter microporous ß-TCP ceramics.

ß-TCP ceramics are versatile bone substitute materials and show many interactions with cells of the monocyte-macrophage-lineage. The possibility of monocytes entering microporous ß-TCP ceramics has however not yet been researched. In this study, we used a model approach to investigate whether monocytes might enter ß-TCP, providing a possible explanation for the origin of CD68-positive osteoclast-like giant cells found in earlier works.We used flow chambers to unidirectionally load BC, PRP, or PPP into slice models of either 2 mm or 6 mm ß-TCP. Immunofluorescence for CD68 and live/dead staining was performed after the loading process.Our results show that monocytes were present in a relevant number of PRP and BC slices representing the inside of our 2 mm slice model and also present on the actual inside of our 6 mm model. For PPP, monocytes were not found beyond the surface in either model.Our results indicate the possibility of a new and so far neglected constituent in ß-TCP degradation, perhaps causing the process of ceramic degradation also starting from inside the ceramics as opposed to the current understanding. We also demonstrated flow chambers as a possible new in vitro model for interactions between blood and ß-TCP.

Biomimetic bone-periosteum scaffold for spatiotemporal regulated innervated bone regeneration and therapy of osteosarcoma.

The complexity of repairing large segment defects and eradicating residual tumor cell puts the osteosarcoma clinical management challenging. Current biomaterial design often overlooks the crucial role of precisely regulating innervation in bone regeneration. Here, we develop a Germanium Selenium (GeSe) co-doped polylactic acid (PLA) nanofiber membrane-coated tricalcium phosphate bioceramic scaffold (TCP-PLA/GeSe) that mimics the bone-periosteum structure. This biomimetic scaffold offers a dual functionality, combining piezoelectric and photothermal conversion capabilities while remaining biodegradable. When subjected to ultrasound irradiation, the US-electric stimulation of TCP-PLA/GeSe enables spatiotemporal control of neurogenic differentiation. This feature supports early innervation during bone formation, promoting early neurogenic differentiation of Schwann cells (SCs) by increasing intracellular Ca2+ and subsequently activating the PI3K-Akt and Ras signaling pathways. The biomimetic scaffold also demonstrates exceptional osteogenic differentiation potential under ultrasound irradiation. In rabbit model of large segment bone defects, the TCP-PLA/GeSe demonstrates promoted osteogenesis and nerve fibre ingrowth. The combined attributes of high photothermal conversion capacity and the sustained release of anti-tumor selenium from the TCP-PLA/GeSe enable the synergistic eradication of osteosarcoma both in vitro and in vivo. This strategy provides new insights on designing advanced biomaterials of repairing large segment bone defect and osteosarcoma.

Patient-specific beta-tricalcium phosphate scaffold for customized alveolar ridge augmentation: a case report : Case Report: patient-specific ß-TCP scaffold for alveolar ridge CBR.

BACKGROUND: Beta-tricalcium phosphate (ß-TCP) is a biocompatible ceramic material widely used in the field of oral regeneration. Due to its excellent biological and mechanical properties, it is increasingly utilized for alveolar ridge augmentation or guided bone regeneration (GBR). With recent advances in computer-aided design and manufacturing (CAD/CAM), ß-TCP can now be used in the form of digitally designed patient-specific scaffolds for customized bone regeneration (CBR) of advanced defects in a two-stage implant therapy concept. In this case report following the CARE case report guidelines, we present a novel application of a patient-specific ß-TCP scaffold in pre-implant mandibular alveolar ridge augmentation. CASE PRESENTATION: A 63-year-old female patient with significant horizontal bone loss in the posterior mandible was treated with a custom ß-TCP scaffold in the context of a two-stage backward-planned implant therapy. Cone-beam computed tomography nine months after augmentation showed successful integration of the scaffold into the surrounding bone, allowing implant placement. Follow-up until two years after initial surgery showed excellent oral and peri-implant health. CONCLUSIONS: This case highlights the potential of patient-specific ß-TCP scaffolds for alveolar ridge augmentation and their advantage over traditional techniques, including avoidance of xeno-, allo-, and autografts. The results provide encouraging evidence for their use in clinical practice. Patient-specific ß-TCP scaffolds may be a promising alternative for clinicians seeking to provide their patients with safe, predictable, and effective alveolar ridge augmentation results in customized bone regeneration procedures.

Comparative Studies of Bone Graft and Orthobiologics for Foot Ankle Arthrodesis: A Critical Review.

Graft materials available to supplement hindfoot and ankle arthrodesis procedures include autologous (autograft) or allogeneic bone graft (allograft) but also bone graft substitutes such as demineralized bone matrix, calcium sulfate, calcium phosphate, and tricalcium phosphate/hydroxyapatite. In addition, biologic agents, such as recombinant human bone morphogenetic protein-2 or recombinant human platelet derived growth factor-BB (rhPDGF-BB), and preparations, including platelet-rich plasma or concentrated bone marrow aspirate, have been used to facilitate bone healing in ankle or hindfoot arthrodesis. The purpose of this review was to summarize the available clinical evidence surrounding the utilization and efficacy of the above materials and biological agents in ankle or hindfoot arthrodesis procedures, with emphasis on the quality of the existing evidence to facilitate clinical decision making.

Mesenchymal Stem Cell Exosomes Enhance Posterolateral Spinal Fusion in a Rat Model.

Spinal fusion, a common surgery performed for degenerative lumbar conditions, often uses recombinant human bone morphogenetic protein 2 (rhBMP-2) that is associated with adverse effects. Mesenchymal stromal/stem cells (MSCs) and their extracellular vesicles (EVs), particularly exosomes, have demonstrated efficacy in bone and cartilage repair. However, the efficacy of MSC exosomes in spinal fusion remains to be ascertained. This study investigates the fusion efficacy of MSC exosomes delivered via an absorbable collagen sponge packed in a poly Ɛ-caprolactone tricalcium phosphate (PCL-TCP) scaffold in a rat posterolateral spinal fusion model. Herein, it is shown that a single implantation of exosome-supplemented collagen sponge packed in PCL-TCP scaffold enhanced spinal fusion and improved mechanical stability by inducing bone formation and bridging between the transverse processes, as evidenced by significant improvements in fusion score and rate, bone structural parameters, histology, stiffness, and range of motion. This study demonstrates for the first time that MSC exosomes promote bone formation to enhance spinal fusion and mechanical stability in a rat model, supporting its translational potential for application in spinal fusion.

The Rise in Tubular pH during Hypercalciuria Exacerbates Calcium Stone Formation.

In calcium nephrolithiasis (CaNL), most calcium kidney stones are identified as calcium oxalate (CaOx) with variable amounts of calcium phosphate (CaP), where CaP is found as the core component. The nucleation of CaP could be the first step of CaP+CaOx (mixed) stone formation. High urinary supersaturation of CaP due to hypercalciuria and an elevated urine pH have been described as the two main factors in the nucleation of CaP crystals. Our previous in vivo findings (in mice) show that transient receptor potential canonical type 3 (TRPC3)-mediated Ca2+ entry triggers a transepithelial Ca2+ flux to regulate proximal tubular (PT) luminal [Ca2+], and TRPC3-knockout (KO; -/-) mice exhibited moderate hypercalciuria and microcrystal formation at the loop of Henle (LOH). Therefore, we utilized TRPC3 KO mice and exposed them to both hypercalciuric [2% calcium gluconate (CaG) treatment] and alkalineuric conditions [0.08% acetazolamide (ACZ) treatment] to generate a CaNL phenotype. Our results revealed a significant CaP and mixed crystal formation in those treated KO mice (KOT) compared to their WT counterparts (WTT). Importantly, prolonged exposure to CaG and ACZ resulted in a further increase in crystal size for both treated groups (WTT and KOT), but the KOT mice crystal sizes were markedly larger. Moreover, kidney tissue sections of the KOT mice displayed a greater CaP and mixed microcrystal formation than the kidney sections of the WTT group, specifically in the outer and inner medullary and calyceal region; thus, a higher degree of calcifications and mixed calcium lithiasis in the kidneys of the KOT group was displayed. In our effort to find the Ca2+ signaling pathophysiology of PT cells, we found that PT cells from both treated groups (WTT and KOT) elicited a larger Ca2+ entry compared to the WT counterparts because of significant inhibition by the store-operated Ca2+ entry (SOCE) inhibitor, Pyr6. In the presence of both SOCE (Pyr6) and ROCE (receptor-operated Ca2+ entry) inhibitors (Pyr10), Ca2+ entry by WTT cells was moderately inhibited, suggesting that the Ca2+ and pH levels exerted sensitivity changes in response to ROCE and SOCE. An assessment of the gene expression profiles in the PT cells of WTT and KOT mice revealed a safeguarding effect of TRPC3 against detrimental processes (calcification, fibrosis, inflammation, and apoptosis) in the presence of higher pH and hypercalciuric conditions in mice. Together, these findings show that compromise in both the ROCE and SOCE mechanisms in the absence of TRPC3 under hypercalciuric plus higher tubular pH conditions results in higher CaP and mixed crystal formation and that TRPC3 is protective against those adverse effects.

Inhibiting Pathological Calcium Phosphate Mineralization: Implications for Disease Progression.

Pathological calcifications, especially calcium phosphate microcalcifications (MCs), appear in most early breast cancer lesions, and their formation correlates with more aggressive tumors and a poorer prognosis. Hydroxyapatite (HA) is a key MC component that crystallizes in the tumor microenvironment. It is often associated with malignant breast cancer lesions and can trigger tumorigenesis in vitro. Here, we investigate the impact of additives on HA crystallization and inhibition, and how precancerous breast cells respond to minerals that are deposited in the presence of these additives. We show that nonstoichiometric HA spontaneously crystallizes in a solution simulating the tumor microenvironmental fluids and exhibits lump-like morphology similar to breast cancer MCs. In this system, the effectiveness of poly(aspartic acid) and poly(acrylic acid) (PAA) to inhibit HA is examined as a potential route to improve cancer prognosis. In the presence of additives, the formation of HA lumps is associated with the promotion or only minimal inhibition of mineralization, whereas the formation of amorphous calcium phosphate (ACP) lumps is followed by inhibition of mineralization. PAA emerges as a robust HA inhibitor by forming spherical ACP particles. When precancerous breast cells are exposed to various HA and ACP minerals, the most influential factors on cell proliferation are the mineral phase and whether the mineral is in the form of discrete particles or particle aggregates. The tumorigenic effects on cells, ranging from cytotoxicity and suppression of proliferation to triggering of proliferation, can be summarized as HA particles < HA aggregates < ACP particles < ACP aggregates. The cellular response to minerals can be attributed to a combination of factors, including mineral phase, crystallinity, morphology, surface texture, aggregation state, and surface potential. These findings have implications for understanding mineral-cell interactions within the tumor microenvironment and suggest that, in some cases, the byproducts of HA inhibition can contribute to disease progression more than HA itself.

Objective sputum colour assessment and clinical outcomes in bronchiectasis: data from the European Bronchiectasis Registry (EMBARC).

BACKGROUND: A validated 4-point sputum colour chart can be used to objectively evaluate the levels of airway inflammation in bronchiectasis patients. In the European Bronchiectasis Registry (EMBARC), we tested whether sputum colour would be associated with disease severity and clinical outcomes. METHODS: We used a prospective, observational registry of adults with bronchiectasis conducted in 31 countries. Patients who did not produce spontaneous sputum were excluded from the analysis. The Murray sputum colour chart was used at baseline and at follow-up visits. Key outcomes were frequency of exacerbations, hospitalisations for severe exacerbations and mortality during up to 5-year follow-up. RESULTS: 13 484 patients were included in the analysis. More purulent sputum was associated with lower forced expiratory volume in 1 s (FEV1), worse quality of life, greater bacterial infection and a higher bronchiectasis severity index. Sputum colour was strongly associated with the risk of future exacerbations during follow-up. Compared to patients with mucoid sputum (reference group), patients with mucopurulent sputum experienced significantly more exacerbations (incident rate ratio (IRR) 1.29, 95% CI 1.22-1.38; p<0.0001), while the rates were even higher for patients with purulent (IRR 1.55, 95% CI 1.44-1.67; p<0.0001) and severely purulent sputum (IRR 1.91, 95% CI 1.52-2.39; p<0.0001). Hospitalisations for severe exacerbations were also associated with increasing sputum colour with rate ratios, compared to patients with mucoid sputum, of 1.41 (95% CI 1.29-1.56; p<0.0001), 1.98 (95% CI 1.77-2.21; p<0.0001) and 3.05 (95% CI 2.25-4.14; p<0.0001) for mucopurulent, purulent and severely purulent sputum, respectively. Mortality was significantly increased with increasing sputum purulence, hazard ratio 1.12 (95% CI 1.01-1.24; p=0.027), for each increment in sputum purulence. CONCLUSION: Sputum colour is a simple marker of disease severity and future risk of exacerbations, severe exacerbations and mortality in patients with bronchiectasis.

Evolution and diversity of biomineralized columnar architecture in early Cambrian phosphatic-shelled brachiopods.

Biologically-controlled mineralization producing organic-inorganic composites (hard skeletons) by metazoan biomineralizers has been an evolutionary innovation since the earliest Cambrian. Among them, linguliform brachiopods are one of the key invertebrates that secrete calcium phosphate minerals to build their shells. One of the most distinct shell structures is the organo-phosphatic cylindrical column exclusive to phosphatic-shelled brachiopods, including both crown and stem groups. However, the complexity, diversity, and biomineralization processes of these microscopic columns are far from clear in brachiopod ancestors. Here, exquisitely well-preserved columnar shell ultrastructures are reported for the first time in the earliest eoobolids Latusobolus xiaoyangbaensis gen. et sp. nov. and Eoobolus acutulus sp. nov. from the Cambrian Series 2 Shuijingtuo Formation of South China. The hierarchical shell architectures, epithelial cell moulds, and the shape and size of cylindrical columns are scrutinised in these new species. Their calcium phosphate-based biomineralized shells are mainly composed of stacked sandwich columnar units. The secretion and construction of the stacked sandwich model of columnar architecture, which played a significant role in the evolution of linguliforms, is highly biologically controlled and organic-matrix mediated. Furthermore, a continuous transformation of anatomic features resulting from the growth of diverse columnar shells is revealed between Eoobolidae, Lingulellotretidae, and Acrotretida, shedding new light on the evolutionary growth and adaptive innovation of biomineralized columnar architecture among early phosphatic-shelled brachiopods during the Cambrian explosion.

Hierarchical antibiotic delivery system based on calcium phosphate cement/montmorillonite-gentamicin sulfate with drug release pathways.

Antibiotic-loaded calcium phosphate cement (CPC) has emerged as a promising biomaterial for drug delivery in orthopedics. However, there are problems such as the burst release of antibiotics, low cumulative release ratio, inappropriate release cycle, inferior mechanical strength, and poor anti-collapse properties. In this research, montmorillonite-gentamicin (MMT-GS) was fabricated by solution intercalation method and served as the drug release pathways in CPC to avoid burst release of GS, achieving promoted cumulative release ratios and a release cycle matched the time of inflammatory response. The results indicated that the highest cumulative release ratio and release concentration of GS in CPC/MMT-GS was 94.1 ± 2.8 % and 1183.05 µg/mL, and the release cycle was up to 504 h. In addition, the hierarchical GS delivery system was divided into three stages, and the kinetics followed the Korsmeyer-Peppas model, the zero-order model, and the diffusion-dissolution model, respectively. Meanwhile, the compressive strength of CPC/MMT-GS was up to 51.33 ± 3.62 MPa. Antibacterial results demonstrated that CPC/MMT-GS exhibited excellent in vitro long-lasting antibacterial properties to E. coli and S. aureus. Furthermore, CPC/MMT-GS promoted osteoblast proliferation and exhibited excellent in vivo histocompatibility. Therefore, CPC/MMT-GS has favorable application prospects in the treatment of bone defects with bacterial infections and inflammatory reactions.