Photodynamic black phosphorus nanosheets functionalized with polymyxin B for targeted ablation of drug-resistant mixed-species biofilms.

Biofilms, particularly those formed by multiple bacterial species, pose significant economic and environmental challenges, especially in the context of medical implants. Addressing the urgent need for effective treatment strategies that do not exacerbate drug resistance, we developed a novel nanoformulation, Ce6&PMb@BPN, based on black phosphorus nanosheets (BPN) for targeted treatment of mixed-species biofilms formed by Acinetobacter baumannii (A. baumannii) and methicillin-resistant Staphylococcus aureus (MRSA).The formulation leverages polymyxin B (PMb) for bacterial targeting and chlorin e6 (Ce6) for photodynamic action. Upon near-infrared (NIR) irradiation, Ce6&PMb@BPN efficiently eliminates biofilms by combining chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), reducing biofilm biomass significantly within 30 min. In vivo studies on mice infected with mixed-species biofilm-coated catheters demonstrated the formulation's potent antibacterial and biofilm ablation effects. Moreover, comprehensive biosafety evaluations confirmed the excellent biocompatibility of Ce6&PMb@BPN. Taken together, this intelligently designed nanoformulation holds potential for effectively treating biofilm-associated infections, addressing the urgent need for strategies to combat antibiotic-resistant biofilms, particularly mixed-species biofilm, in medical settings.

The effect of bacteria on uranium sequestration stability by different forms of phosphorus.

Immobilisation of uranium (U (VI)) by direct precipitation of uranyl phosphate (U-P) exhibits a great potential application in the remediation of U (VI)-contaminated environments. However, phosphorus, vital element of bacteria's decomposition, absorption and transformationmay affect the stability of U (VI) with ageing time. The main purpose of this work is to study the effect of bacteria on uranium sequestration mechanism and stability by different forms of phosphorus in a water sedimentary system. The results showed that phosphate effectively enhanced the removal of U (VI), with 99.84%. X-Ray Diffraction (XRD), Scanning Electron Microscopy and Energy Dispersive Spectrometer (SEM-EDS), and X-ray Photoelectron Spectroscopy (XPS) analyses imply that U (VI) and U (IV) co-exist on the surface of the samples. Combined with BCR results, it demonstrated that bacteria and phosphorus have a synergistic effect on the removal of U (VI), realising the immobilisation of U (VI) from a transferable phase to a stable phase. However, from a long-term perspective, the redissolution and release of uranium immobilisation of U (VI) by pure bacteria with ageing time are worthy of attention, especially in uranium mining environments rich in sensitive substances. This observation implies that the stability of the uranium may be impacted by the prevailing environmental conditions. The novel findings could provide theoretical evidence for U (VI) bio-immobilisation in U (VI)-contaminated environments.

Self-Healing Dynamic Hydrogel Microparticles with Structural Color for Wound Management.

Chronic diabetic wounds confront a significant medical challenge because of increasing prevalence and difficult-healing circumstances. It is vital to develop multifunctional hydrogel dressings, with well-designed morphology and structure to enhance flexibility and effectiveness in wound management. To achieve these, we propose a self-healing hydrogel dressing based on structural color microspheres for wound management. The microsphere comprised a photothermal-responsive inverse opal framework, which was constructed by hyaluronic acid methacryloyl, silk fibroin methacryloyl and black phosphorus quantum dots (BPQDs), and was further re-filled with a dynamic hydrogel. The dynamic hydrogel filler was formed by Knoevenagel condensation reaction between cyanoacetate and benzaldehyde-functionalized dextran (DEX-CA and DEX-BA). Notably, the composite microspheres can be applied arbitrarily, and they can adhere together upon near-infrared irradiation by leveraging the BPQDs-mediated photothermal effect and the thermoreversible stiffness change of dynamic hydrogel. Additionally, eumenitin and vascular endothelial growth factor were co-loaded in the microspheres and their release behavior can be regulated by the same mechanism. Moreover, effective monitoring of the drug release process can be achieved through visual color variations. The microsphere system has demonstrated desired capabilities of controllable drug release and efficient wound management. These characteristics suggest broad prospects for the proposed composite microspheres in clinical applications.

Poison to Promise: The Resurgence of Organophosphorus Fluoride Chemistry.

Organophosphorus(V) fluorides have a long and tumultuous history, with early applications as toxins and nerve agents reflecting their poisonous past. Behind these very real safety considerations, there is also growing potential in a wide range of fields, from chemical biology to drug development. The recent inclusion of organophosphorus(V) fluorides in click chemistry exemplifies the promise these compounds possess and brings these molecules to the brink of a resurgence. In this Perspective, we delve into the history of P(V)-F compounds, discuss the precautions needed to work with them safely, and explore recent advancements in their synthesis and application. We conclude by discussing how this field can continue on a path toward innovation.

Unravelling White Phosphorus: Experimental and Computational Studies Reveal the Mechanisms of P4 Hydrostannylation.

The hydrostannylation of white phosphorus (P4) allows this crucial industrial precursor to be easily transformed into useful P1 products via direct, 'one pot' (or even catalytic) procedures. However, a thorough mechanistic understanding of this transformation has remained elusive, hindering attempts to use this rare example of successful, direct P4 functionalization as a model for further reaction development. Here, we provide a deep and generalizable mechanistic picture for P4 hydrostannylation by combining DFT calculations with in situ31P NMR reaction monitoring and kinetic trapping of previously unobservable reaction intermediates using bulky tin hydrides. The results offer important insights into both how this reaction proceeds and why it is successful and provide implicit guidelines for future research in the field of P4 activation.

Effects of wet-dry alternation on organic phosphorus dynamics and sediment characteristics in the intertidal zone of Nansi Lake.

The study of the fractions and distribution characteristics of organic phosphorus in the sediment of the water level fluctuating zone of Nansi Lake is conducive to revealing the transformation of phosphorus in the lake, and has important scientific significance for controlling the eutrophication of Nansi Lake. Based on the sediment of the water level fluctuation zone of Nansi Lake. The improved Hedley continuous grading extraction, ultraviolet-visible spectroscopy and three-dimensional fluorescence spectroscope were used to characterize the structural characteristics and stability of organic molecules in the sediment, and to reflect the differences in the structure and stability of organophosphate in the water level fluctuating zone. Principal component analysis (PCA), Redundancy analysis (RDA) and correlation heat map analysis were used to analyze the correlation between phosphorus and physicochemical index. The results showed that the alternation between wet-dry conditions was more favorable for the release of phosphorus from sediment, compared to continuous inundation conditions. Moreover, the higher the frequency of wet-dry alternations, the greater the release of phosphorus in different forms from the sediment. Wet-dry alternation resulted in a reduction of substituent on the aromatic rings of sediment DOM (dissolved organic matter), and the continuous drying would increase the molecular weight and humidification degree of DOM in the sediment. Correlation analysis showed that NaOH-Po content in sediment was significantly negatively correlated with TP, IP, OP and various organophosphorus forms, indicating a close transformation relationship between phosphorus forms in sediment. The results can provide a scientific basis for controlling the release of endogenous phosphorus and the risk of eutrophication in Nansi Lake.

Salinity affects microbial function genes related to nutrient cycling in arid regions.

Introduction: Salinization damages soil system health and influences microbial communities structure and function. The response of microbial functions involved in the nutrient cycle to soil salinization is a valuable scientific question. However, our knowledge of the microbial metabolism functions in salinized soil and their response to salinity in arid desert environments is inadequate. Methods: Here, we applied metagenomics technology to investigate the response of microbial carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) cycling and the key genes to salinity, and discuss the effects of edaphic variables on microbial functions. Results: We found that carbon fixation dominated the carbon cycle. Nitrogen fixation, denitrification, assimilatory nitrate reduction (ANRA), and nitrogen degradation were commonly identified as the most abundant processes in the nitrogen cycle. Organic phosphorus dissolution and phosphorus absorption/transport were the most enriched P metabolic functions, while sulfur metabolism was dominated by assimilatory sulfate reduction (ASR), organic sulfur transformation, and linkages between inorganic and organic sulfur transformation. Increasing salinity inhibited carbon degradation, nitrogen fixation, nitrogen degradation, anammox, ANRA, phosphorus absorption and transport, and the majority of processes in sulfur metabolism. However, some of the metabolic pathway and key genes showed a positive response to salinization, such as carbon fixation (facA, pccA, korAB), denitrification (narG, nirK, norBC, nosZ), ANRA (nasA, nirA), and organic phosphorus dissolution processes (pstABCS, phnCD, ugpAB). High salinity reduced the network complexity in the soil communities. Even so, the saline microbial community presented highly cooperative interactions. The soil water content had significantly correlations with C metabolic genes. The SOC, N, and P contents were significantly correlated with C, N, P, and S network complexity and functional genes. AP, NH4+, and NO3- directly promote carbon fixation, denitrification, nitrogen degradation, organic P solubilization and mineralization, P uptake and transport, ASR, and organic sulfur transformation processes. Conclusion: Soil salinity in arid region inhibited multiple metabolic functions, but prompted the function of carbon fixation, denitrification, ANRA, and organic phosphorus dissolution. Soil salinity was the most important factor driving microbial functions, and nutrient availability also played important roles in regulating nutrient cycling.

Conquering Challenges: A Case Series of Yellow Phosphorus Poisoning at a Tertiary Care Hospital in Pune, Western India.

Rodenticides are easily available in the market and suicidal attempts by ingesting such poisonous products are commonly reported in rural India. We aimed to analyze predictive factors, biological markers, and treatment outcomes among patients who ingested rodenticides (yellow phosphorus) with the brand name, Rattol. Here, we present three such cases who were admitted to a tertiary care hospital. We recorded socio-demographic characteristics, probable predictive factors, and serial charting biological markers. Conventional treatment was given to these cases. All cases were young women (age range: 17-30 years) from rural areas, two were married and one was unmarried. The approximate quantity of ingestion was 20, 10, and 5 grams, respectively. The time lag between the ingestion and sought first health care was 6 hours, 18 hours, and 1 hour, respectively. Major symptoms were vomiting, abdominal pain, and headache. Biological markers, including total bilirubin, alanine aminotransferase, aspartate aminotransferase, creatinine, prothrombin time, international normalized ratio, and model for end-stage liver disease (MELD) score were statistically significant. Two women had toxic hepatitis and acute liver failure and one did not have any organ damage. All of them were recovered within 17 days of mean hospital stay. A lethal dosage of rodenticides and delayed presentation to the hospital can prompt acute liver failure and severe ailment. Creating awareness, promoting mental health and suicide prevention, and framing proper guidelines for treatment will reduce morbidity and mortality.

Effects of oilseed rape green manure on phosphorus availability of red soil and rice yield in rice-green manure rotation system.

Improving the nutrient content of red soils in southern China is a priority for efficient rice production there. To assess the effectiveness of oilseed rape as green manure for the improvement of soil phosphorus nutrient supply and rice yield in red soil areas, a long-term field plot experiment was conducted comparing two species of rape, Brassica napus (BN) and Brassica juncea (BJ). The effects of returning oilseed rape on soil phosphorus availability, phosphorus absorption, and yield of subsequent rice under rice-green manure rotation mode were analyzed, using data from the seasons of 2020 to 2021. The study found that compared with winter fallow treatment (WT) and no-tillage treatment (NT), the soil available phosphorus content of BN was increased, and that of BJ was significantly increased. The content of water-soluble inorganic phosphorus of BJ increased, and that of BN increased substantially. Compared with the WT, the soil organic matter content and soil total phosphorus content of BN significantly increased, as did the soil available potassium content of BJ, and the soil total phosphorus content of BJ was significantly increased compared with NT. The soil particulate phosphorus content of BJ and BN was significantly increased by 14.00% and 16.00%, respectively. Compared with the WT, the phosphorus activation coefficient of BJ was significantly increased by 11.41%. The rice plant tiller number under the green manure returning treatment was significantly increased by 43.16% compared with the winter fallow treatment. The green manure returning measures increased rice grain yield by promoting rice tiller numbers; BN increased rice grain yield by 9.91% and BJ by 11.68%. Based on these results, returning oilseed rape green manure could augment the phosphorus nutrients of red soil and promote phosphorus availability. Rice-oilseed rape green manure rotation could increase rice grain yield.

Electrophilic C(sp2)-H Cyanation with Inorganic Cyanate (OCN-) by PIII/PV=O-Catalyzed Phase Transfer Activation.

An organophosphorus redox-catalyzed method for the direct electrophilic cyanation of C(sp2)-H nucleophiles with sodium cyanate (NaOCN) is reported. The catalytic deoxyfunctionalization of the OCN- anion is enabled by the use of a small-ring phosphacyclic (phosphetane) catalyst in combination with a terminal hydrosilane O-atom acceptor and a malonate-derived bromenium donor. In situ spectroscopy under single-turnover conditions demonstrate that insoluble inorganic cyanate anion is activated by bromide displacement on a bromophosphonium catalytic intermediate to give a reactive N-bound isocyanatophosphonium ion, which delivers electrophilic "CN+" equivalents to nucleophilic (hetero)arenes and alkenes with loss of a phosphine oxide. These results demonstrate the feasibility of deoxyfunctionalization of insoluble inorganic salts by PIII/PV=O catalyzed phase transfer activation.

Study on the reaction kinetics of simultaneous recovery of iron phosphate from hypophosphite in perferite oxidation plating waste.

Phosphorus is an indispensable and irreplaceable element in the ecosystem. Based on the ability of ferrate(VI) to remove phosphate by producing iron phosphate, a new method for using ferrate(VI) to treat hypophosphite has been studied. In this study, ferrate was added to the hypophosphate solution in a controlled manner, and the oxidation efficiency of ferrate(VI) on hypophosphate was studied under various initial pH conditions, when the pH value of 6.0, the hypophosphate oxidation rate reached 14.0%. Research findings, Ferrate recovered hypophosphate through precipitation and adsorption under various initial pH conditions. To further investigate the mechanism of hypophosphate recovery, the morphology and microstructure of the deposition were analysed using Fourier transform infrared, X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The kinetic process of ferrate recovery from hypophosphate was analysed. The recovery process follows second-order reaction kinetics, and the reaction rate is highest at pH 6.0. The value of kA1 is 1.742 × 10-2. This study shows that ferrate (VI) is a promising treatment tool for low-cost phosphate wastewater. Furthermore, this method offers a clean phosphorus recovery process without the generation of harmful substances.

Developing a method to measure bioavailable phosphorus in river water via simultaneous multisample ultrasonic extraction.

To reduce aquatic eutrophication, measurements of bioavailable phosphorus (BAP) rather than total phosphorus (TP) are deemed critical. However, current methods require much time to separate sediments from river water, which limits the routine measurement of BAP in rivers. Therefore, in this study, a simultaneous multisample ultrasonic extraction method is proposed to directly measure total BAP (TBAP) in river water without the separation of sediment and water. Spike-and-recovery assessments showed that at least three extractions are required to maintain efficiency. A process including 2-min extraction time and three extractions was suggested. The concentrations of TBAP extracted by this process showed no significant differences with the spike calculations. Furthermore, river water TBAP was quantified using the conventional and proposed method to examine the practicality of using the proposed method for simultaneous multisample ultrasonic extraction and to evaluate its adaptability to actual river water analysis. The extracted concentrations matched those obtained using the conventional method, in which total BAP is calculated as the sum of dissolved BAP and particulate BAP; no significant difference was observed between the concentrations. Ultrasonic extraction was considerably less time-consuming than the conventional method because more samples could be analyzed during a single run. Therefore, the simultaneous multisample ultrasonic extraction method proposed in this study can be used to directly quantify total BAP in river water.

Homogeneous Adsorption of Multiple Potassiation Products of Red Phosphorus Anode toward Stable Potassium Storage.

Potassium ion batteries (PIBs) are a viable alternative to lithium-ion batteries for energy storage. Red phosphorus (RP) has attracted a great deal of interest as an anode for PIBs owing to its cheapness, ideal electrode potential, and high theoretical specific capacity. However, the direct preparation of phosphorus-carbon composites usually results in exposure of the RP to the exterior of the carbon layer, which can lead to the deactivation of the active material and the production of "dead phosphorus". Here, the advantage of the π-π bond conjugated structure and high catalytic activity of metal phthalocyanine (MPc) is used to prepare MPc@RP/C composites as a highly stable anode for PIBs. It is shown that the introduction of MPc greatly improves the uneven distribution of the carbon layer on RP, and thus improves the initial Coulombic efficiency (ICE) of PIBs (the ICE of FePc@RP/C is 75.5% relative to 62.9% of RP/C). The addition of MPc promotes the growth of solid electrolyte interphase with high mechanical strength, improving the cycle stability of PIBs (the discharge-specific capacity of FePc@RP/C is 411.9 mAh g-1 after 100 cycles at 0.05 A g-1). Besides, density functional theory theoretical calculations show that MPc exhibits homogeneous adsorption energies for multiple potassiation products, thereby improving the electrochemical reactivity of RP. The use of organic molecules with high electrocatalytic activity provides a universal approach for designing superior high-capacity, large-volume expansion anodes for PIBs.

Dual-Atom P-Co-Dy Charge-Transfer Bridge on Black Phosphorus for Enhanced Photocatalytic CO2 Reduction.

The synergistic effect of rare earth single-atoms and transition metal single-atoms may enable us to achieve some unprecedented performance and characteristics. Here, Co-Dy dual-atoms on black phosphorus with a P-Co-Dy charge-transfer bridge are designed and fabricated as the active center for the CO2 photoreduction reaction. The synergistic effect of Co-Dy on the performance of black phosphorus is studied by combining X-ray absorption spectroscopy, ultrafast spectral analysis, and in situ technology with DFT calculations. The results show that the Co and Dy bimetallic active site can promote charge transfer by the charge transfer bridge from P to Dy, and then to Co, thereby improving the photocatalytic activity of black phosphorus. The performance of catalysts excited at different wavelength light indicates that the 4G11/2/2I15/2/4F9/2→6H15/2 and 4F9/2→6H13/2 emissions of Dy can be absorbed by black phosphorus to improve the utilization of sunlight. The in situ DRIFTS and density functional theory (DFT) calculations are used to investigate the CO2 photoreduction pathway. This work provides an depth insight into the mechanism of dual-atom catalysts with enhanced photocatalytic performance, which helps to design novel atomic photocatalysts with excellent activity for CO2 reduction reactions.

Phosphonium SF5- Salts Derived from Sulfur Hexafluoride as Deoxyfluorination Reagents.

Sulfur based deoxyfluorination reagents are usually derived from the corrosive gas SF4. Herein, we report the synthesis and properties of an easily accessible phosphonium salt [(tmg)3PF]+SF5- (1) which was obtained from the reaction of sulfur hexafluoride (SF6) with tris(tetramethylguanidinyl)phosphine. The performance of this crystalline SF5- salt as a reagent in deoxyfluorination reactions was investigated together with a second SF5- salt [(R1)3PF]+SF5- (2) containing bulky substituents (R1 = 1,3-di-tert-butylimidazolidin-2-ylidenamino). Both reagents proved to be effective for the deoxyfluorination of various functional groups including alcohols, anhydrides, and amides.

Computational studies on a selection of phosphite esters as antioxidants for polymeric materials.

CONTEXT: Phosphite esters, a class of organo-phosphorus compounds, are widely used as non-discolouring antioxidants in many polymeric products. Apart from normal radical scavenging, they prevent the splitting of hydroperoxides (ROOH), one of the initial products of autoxidation, from forming extremely reactive free radicals such as alkoxy (RO.) and hydroxy (.OH) radicals. The inherent molecular properties of antioxidants and the chemistry of their action are essential for researchers working in this field of science. Four organo-phosphorous compounds well-known for their antioxidant activity are selected here for theoretical analysis: Tri(m-methylphenyl) phosphite (m-TMPP), Tri(4-methyl-2,6-di-tert-butylphenyl) phosphite (TMdtBPP), Tri(allylphenyl) phosphite (TAPP) and Tri(mercaptobenzothiazoyl) thiophosphate (TMBTTP). The antioxidant activity exhibited by these compounds is theoretically verified, and the results are consistent with the available experimental data. Such theoretical predictions offer advantages in scientific research, particularly when researchers need to select certain molecules as antioxidants for experiments from a pool of molecular systems. METHODS: The chemical computations presented in this report are done in Gaussian 16 program package. The procedure of density functional theory (DFT) with the model chemistry B3LYP/6-31G(d,p) is used to generate computational data. Global reactivity indices, thermochemical data, Fukui functions, molecular electrostatic potential and NMR spectra are computed for the chosen molecular systems from their optimized geometries.

Bibliometric and visual analysis in the field of two-dimensions nano black phosphorus in cancer from 2015 to 2023.

This study aims to provide a comprehensive summary of the status and trends of Two-Dimensional Nano Black Phosphorus (2D nano BP) in cancer research from 2015 to 2023, offering insights for future studies. To achieve this, articles from the Web of Science database published between 2015 and 2023 were analyzed using R and VOSviewer software. The analysis included 446 articles, revealing a consistent increase in publication rates, especially between 2017 and 2019. China emerged as a leader in both publication volume and international collaborations. Prominent journals in this field included ACS Applied Materials & Interfaces and Advanced Materials, while key researchers were identified as Zhang Han, Tao Wei, and Yu Xuefeng. The analysis highlighted common keywords such as drug delivery, photothermal therapy, photodynamic therapy, and immunotherapy, indicating the major research focuses. The findings suggest that 2D nano BP holds significant promise in cancer treatment research, with a growing global interest. This study thus serves as a valuable reference for future investigations, providing a detailed analysis of the current state and emerging trends in this promising field.

Exploring the biotechnological potential of novel soil-derived Klebsiella sp. and Chryseobacterium sp. strains using phytate as sole carbon source.

Phosphorus (P) is essential for biological systems, playing a pivotal role in energy metabolism and forming crucial structural components of DNA and RNA. Yet its bioavailable forms are scarce. Phytate, a major form of stored phosphorus in cereals and soils, is poorly bioavailable due to its complex structure. Phytases, enzymes that hydrolyze phytate to release useable phosphorus, are vital in overcoming this limitation and have significant biotechnological applications. This study employed novel method to isolate and characterize bacterial strains capable of metabolizing phytate as the sole carbon and phosphorus source from the Andes mountains soils. Ten strains from the genera Klebsiella and Chryseobacterium were isolated, with Chryseobacterium sp. CP-77 and Klebsiella pneumoniae CP-84 showing specific activities of 3.5 ± 0.4 nkat/mg and 40.8 ± 5 nkat/mg, respectively. Genomic sequencing revealed significant genetic diversity, suggesting CP-77 may represent a novel Chryseobacterium species. A fosmid library screening identified several phytase genes, including a 3-phytase in CP-77 and a glucose 1-phosphatase and 3-phytase in CP-84. Phylogenetic analysis confirmed the novelty of these enzymes. These findings highlight the potential of phytase-producing bacteria in sustainable agriculture by enhancing phosphorus bioavailability, reducing reliance on synthetic fertilizers, and contributing to environmental management. This study expands our biotechnological toolkit for microbial phosphorus management and underscores the importance of exploring poorly characterized environments for novel microbial functions. The integration of direct cultivation with metagenomic screening offers robust approaches for discovering microbial biocatalysts, promoting sustainable agricultural practices, and advancing environmental conservation.

A black phosphorus nanosheet-based RNA delivery system for prostate cancer therapy by increasing the expression level of tumor suppressor gene PTEN via CeRNA mechanism.

BACKGROUND: Prostate cancer (PCa) has a high incidence in men worldwide, and almost all PCa patients progress to the androgen-independent stage which lacks effective treatment measures. PTENP1, a long non-coding RNA, has been shown to suppress tumor growth through the rescuing of PTEN expression via a competitive endogenous RNA (ceRNA) mechanism. However, PTENP1 was limited to be applied in the treatment of PCa for the reason of rapid enzymatic degradation, poor intracellular uptake, and excessively long base sequence to be synthesized. Considering the unique advantages of artificial nanomaterials in drug loading and transport, black phosphorus (BP) nanosheet was employed as a gene-drug carrier in this study. RESULTS: The sequence of PTENP1 was adopted as a template which was randomly divided into four segments with a length of about 1000 nucleotide bases to synthesize four different RNA fragments as gene drugs, and loaded onto polyethyleneimine (PEI)-modified BP nanosheets to construct BP-PEI@RNA delivery platforms. The RNAs could be effectively delivered into PC3 cells by BP-PEI nanosheets and elevating PTEN expression by competitive binding microRNAs (miRNAs) which target PTEN mRNA, ultimately exerting anti-tumor effects. CONCLUSIONS: Therefore, this study demonstrated that BP-PEI@RNAs is a promising gene therapeutic platform for PCa treatment.

Differences in intestinal and renal Ca and P uptake in three different breeds of growing-finishing pigs.

This study investigated the differences in bone growth and turnover and calcium (Ca) and phosphorus (P) uptake among three different breeds of growing-finishing pigs. Ninety healthy Duroc, Xiangcun black (XCB), and Taoyuan black (TYB) pigs (30 pigs per breed) at 35 day-old (D) with the average body weight (BW) of their respective breed were assigned and raised to 185 D. The results showed that Duroc pigs had higher bone weight and length than the XCB and TYB pigs at 80, 125, and 185 D and the bone index at 185 D (p < 0.05). Duroc pigs had higher bone mineral densities (femur and tibia) compared with the other two breeds at 80 D and 125 D, whereas TYB pigs had higher mineral content and bone breaking load (rib) compared with the other two breeds at 185 D (p < 0.05). The bone morphogenetic protein-2 and osteocalcin concentrations were higher, and TRACP5b concentration was lower in serum of TYB pigs at 125 D (p < 0.05). Meanwhile, 1,25-dihydroxyvitamin D3, parathyroid hormone, thyroxine, and fibroblast growth factor 23 concentrations were higher in serum of TYB pigs at 185 D (p < 0.05). The TYB pigs had higher apparent total tract digestibility of P at 80 D and 185 D and bone Ca and P contents at 185 D in comparison to the Duroc pigs (p < 0.05). Furthermore, gene expressions related to renal uptake of Ca and P differed among the three breeds of pigs. Collectively, Duroc pigs have higher bone growth, whereas TYB pigs have a higher potential for mineral deposition caused by more active Ca uptake.