High Capacity Research Articles

Enhancement of Trihalomethane Adsorption Capacity Using Chitosan-Modified Coconut Shell Activated Carbon: Adsorption Characteristics and Mechanisms

There is a rising concern about the safety risk that trihalomethanes (THMs) in drinking water pose. In this work, to adsorb THMs such as chloroform (TCM), dibromochloromethane (DBCM), bromodichloromethane (BDCM), and bromoform (TBM), we coated chitosan (CS) on coconut shell activated carbon (CAC). The adsorbents were characterized using BET, XRD, FTIR, and SEM techniques. The impact of various variables was examined, including contact time, quantity of adsorbent, initial pH, and initial THM concentrations. Under the same conditions, TCM was adsorbed most efficiently, followed by BDCM, DBCM, and TBM. When the pH was between 4 and 8, the adsorption of THMs onto the coconut shell activated carbon supported chitosan (CS/CAC) varied relatively little; however, when the pH increased above 8, the adsorption of THMs decreased. For THMs, CS/CAC adsorption was a chemical reaction and monolayer adsorption that fit better with the pseudo-second-order kinetic model and the Langmuir isotherm model. According to the thermodynamic study, THMs were adsorbed endothermically and spontaneously on CS/CAC. For column experiments, the adsorption of THMs was influenced by bed height and flow rate. After up to four cycles of adsorption and desorption, it was found that the adsorbent was reusable. The maximum adsorption capacities for Langmuir were 187.27, 114.29, 93.28, and 89.61 µg/g for TCM, BDCM, DBCM, and TBM, respectively. CS/CAC has a high adsorption capacity, especially for TCM, which is responsible for a major portion of THMs in drinking water. This indicates that CS/CAC has a lot of potential uses when it comes to removing THMs from water.

Supramolecular Crystals based Fast Single Ion Conductor for Long‐Cycling Solid Zinc Batteries

AbstractThe solid polymer electrolytes (SPEs) used in Zn‐ion batteries (ZIBs) have low ionic conductivity due to the sluggish dynamics of polymer segments. Thus, only short‐range movement of cations is supported, leading to low ionic conductivity and Zn2+ transference (tZn2+). Zn‐based supramolecular crystals (ZMCs) have considerable potential for supporting long‐distance Zn2+ transport; however, their efficiency in ZIBs has not been explored. The present study developed a ZMC consisting of succinonitrile (SN) and zinc bis (trifluoromethylsulfonyl) imide (Zn(TFSI)2), with a structural formula identified as Zn(TFSI)2SN3. The ZMC has ordered three‐dimensional tunnels in the crystalline lattices for ion conduction, providing high ionic conductivities (6.02×10−4 S cm−1 at 25 °C and 3.26×10−5 S cm−1 at −35 °C) and a high tZn2+ (0.97). We demonstrated that a Zn‖Zn symmetrical battery with ZMCs has long‐term cycling stability (1200 h) and a dendrite‐free Zn plating/stripping process, even at a high plating areal density of 3 mAh cm−2. The as‐fabricated solid‐state Zn battery exhibited excellent performance, including high discharge capacity (1.52 mAh cm−2), long‐term cycling stability (83.6 % capacity retention after 70000 cycles (7 months)), wide temperature adaptability (−35 to 50 °C) and fast charging ability. The ZMC differs from SPEs in its structure for transporting Zn2+ ions, significantly improving solid‐state ZIBs while maintaining safety, durability, and sustainability.

Development and verification of material models in modeling of wave strain hardening and additive synthesis processes

BACKGROUND: The creation of competitive machine parts capable of withstanding standard and increased operational loads is an urgent task in mechanical engineering. Developing additive synthesis technologies together with strengthening technologies make it possible to create such products with high load-bearing capacity. However, to improve the efficiency of these technologies, it is necessary to create theoretical models of the processes taking place. The article presents the results of the first stage of creating complex theoretical models of the combined 3DMP process and wave strain hardening (WSH) required for designing technological processes for manufacturing engine parts and brake systems of automotive equipment. . AIMS: Creation and assessment of the adequacy of material models used in finite element modeling of additive synthesis processes with subsequent hardening. MATERIALS AND METHODS: Theoretical models of the material were created in the ANSYS software package, which allows for multidisciplinary calculations. The experimental data required for preparing the models were obtained by testing tensile samples manufactured using standardized methods. The hardness of materials was studied using a KB 30S automatic hardness tester. The adequacy of additive synthesis modeling was assessed based on the distribution of temperature fields. The adequacy of material models for the VDU process was assessed based on the sizes of individual plastic indentations and the distribution diagrams of the depth and degree of hardening in the surface layer. RESULTS: Theoretical models of the following materials were developed: steel, stainless steel, bronze alloy, titanium alloy, aluminum alloy. The theoretical data obtained from the modeling results have a high level of significance. The studies were conducted for various thermal (in the range from +20ºС to +800ºС) and deformation modes. Graphical results of theoretical and experimental studies allow us to obtain a qualitative assessment of the processes under study with the required accuracy. CONCLUSIONS: As a result of the assessment of the adequacy of the developed models, it was established that the discrepancy between the empirical and theoretical data does not exceed 7.4%. The obtained models of materials are statistically significant and can be correctly applied in further studies.

Improving Oxygen-Redox-Active Layered Oxide Cathodes for Sodium-Ion Batteries Through Crystal Facet Modulation and Fluorinated Interfacial Engineering.

Layered oxides with active oxygen redox are attractive cathode materials for sodium-ion batteries (SIBs) due to high capacity but suffer from rapid capacity/voltage deterioration and sluggish reaction kinetics stemming from lattice oxygen release, interfacial side reactions, and structural reconstruction. Herein, a synergistic strategy of crystal-facet modulation and fluorinated interfacial engineering is proposed to achieve high capacity, superior rate capability, and long cycle stability in Na0.67Li0.24Mn0.76O2. The synthesized single-crystal Na0.67Li0.24Mn0.76O2 (NLMO{010}) featuring increased {010} active facet exposure exhibits faster anionic redox kinetics and delivers a high capacity (272.4 mAh g-1 at 10mA g-1) with superior energy density (713.9Wh kg-1) and rate performance (116.4 mAh g-1 at 1 A g-1). Moreover, by incorporating N-Fluorobenzenesulfonimide (NFBS) as electrolyte additive, the NLMO{010} cathode retains 84.6% capacity after 400 cycles at 500mA g-1 with alleviated voltage fade (0.27mV per cycle). Combined in situ analysis and theoretical calculations unveil dual functionality of NFBS, which results in thin yet durable fluorinated interfaces on the NLMO{010} cathode and hard carbon anode and scavenges highly reactive oxygen species. The results indicate the importance of fast-ion-transfer facet engineering and fluorinated electrolyte formulation to enhance oxygen redox-active cathode materials for high-energy-density SIBs.

Electrospun Mesoporous Ni0.5Zn0.5Fe2O4 - CNT - Hollow Carbon Ternary Composite Nanofibers as High Performance Electrodes for Advanced Symmetric Supercapacitors.

Spinel ferrites have attracted considerable interest in energy storage systems due to their unique magnetic, electrical and catalytic properties. However, they suffer from poor electronic conductivity and low specific capacity. We have addressed this limitation by synthesizing composite hollow carbon nanofibers (HCNF) embedded with nanostructured Nickel Zinc Ferrite (NZF) and Multiwalled carbon nanotubes (CNT), through coaxial electrospinning. These ternary composite nanofibers NZF-CNT-HCNF have a high specific capacity of 833 C g-1 at a current density of 1 A g-1 and have a capacity retention of 90 % after 3000 cycles. Their performance is much better than pure NZF fibers (180 C g-1) or hollow carbon nanofibers (96 C g-1), suggesting synergy between various constituents of the composite. A symmetric supercapacitor fabricated from NZF-CNT-HCNF composite nanofibers (30 % NZF) has a high specific capacity of 302 C g-1 (302 A g-1) at a current density of 1 A g-1 and has a capacity retention of 95 % after 5000 cycles. At the same current density, the device has a high energy density of 39 Whkg-1 and power density of 1000 Wkg-1 at a current density of 1 A g-1. This performance can be attributed to the high specific surface area (776 m2 g-1), mesoporosity (pore size ~4 nm), interconnectedness of the nanofibers and high electrical conductivity of CNTs. These fibers can be used as light-weight high performance electrode materials in advanced energy storage devices.

Na Ions Doped Fe2VO4 Cathode for High Performance Aqueous Zinc-ion Batteries.

Aqueous zinc ion batteries are thought to be a new generation of secondary batteries that will replace lithium-ion batteries due to their great safety and inexpensive cost. In the cathode materials of aqueous zinc ion batteries with long life and high capacity, abundant active sites and crystal structure stability play an important role. In the present work, the strategy of Na+ intercalation of Fe2VO4 (FVO) is proposed, aiming at the insertion of Na+, which not only enriches the active sites, but also sodium and iron ions act as guest species with the negatively charged VOx lattice to provide strong electrostatic attraction to stabilize the lamellar structure. In terms of electrochemical performance, the discharge specific capacity is 370 mAh g-1 at a current density of 0.1 A g-1, and when the current density is arising 5 A g-1, the specific capacity also reaches 200 mAh g-1 after cycling 2000 with a capacity retention of 99 %, which is better than the electrochemical performance of Fe2VO4 (FVO) alone at 50 mAh g-1. The superior electrochemical performance proves that FVO-Na is an ideal cathode material for zinc ion batteries.

Electronic Modulation and Symmetry‐Breaking Engineering of Single‐Atom Catalysts Driving Long‐Cycling Li−S Battery

AbstractDeveloping efficient and durable single‐atom catalysts is vitally important for the sulfur redox reaction (SROR) in Li−S battery, while it remains enormous challenging. Herein, undercoordinated Ni−N3 moieties anchored on N,S‐codoped porous carbon (Ni−NSC) is obtained to enhance the SROR. The experiments and theoretical calculations indicate that the symmetry‐breaking charge transfer in Ni single‐atom catalyst originates from tuning effect of sulfur atoms mediated Ni−N3 moieties, which can both facilitate the chemical adsorption by formation of N−Ni⋅⋅⋅Sn2−, and achieve a rapid redox conversion of polysulfides because of the enhanced electron transfer. As results, the Ni−NSC based Li−S battery delivers a very high initial reversible capacity (1025 mAh g−1 at 1 C), as well as outstanding cycling‐stability for 2400 cycles at 2 C and 3 C, respectively. Noteworthy, the areal capacity can reach 7.8 mAh cm−2 at 0.05 C and a retention capacity of 4.7 mAh cm−2 after 100 cycles at 0.2 C for Ni−NSC based Li−S battery with sulfur loading of 5.88 mg cm−2. This work provides profound insight for rational optimizing microscopic electronic density of active site to promoting SROR in metal‐sulfur batteries.

A MXene Modulator Enabled High‐Loading Iodine Composite Cathode for Stable and High‐Energy‐Density Zn‐I2 Battery

AbstractAchieving both high iodine loading cathode and high Zn anode depth of discharge (DOD) is pivotal to unlocking the full potential of energy‐dense Zn‐I2 batteries. However, this combination exacerbates the detrimental shuttle effect of polyiodide intermediates, significantly impairing the battery's reversibility and stability. Herein, this study reports an advanced high‐loading iodine cathode (denoted as MX‐AB@I) enabled by a multifunctional Ti3C2Tx MXene modulator, which presents high stability and energy density in Zn‐I2 batteries. Through comprehensive experimental and theoretical analyses, the intrinsic regulating mechanisms are elucidated by which the MXene modulator effectively suppresses polyiodide shuttling, enhances iodine conversion kinetics, and dramatically improves Zn anode reversibility. With the aid of the MXene modulator, the MX‐AB@I composite cathode achieves a high iodine mass loading of 23 mg cm−2 and realizes a practically high areal capacity of 4.0 mAh cm−2. When paired with a thin Zn anode (10 µm), this configuration realizes a high Zn DOD of 78.7% and a high energy density of 171.3 Wh kg−1, surpassing the majority of Zn‐I2 battery systems reported in the literature. This study presents an effective approach to designing high‐loading iodine cathodes for Zn‐I2 batteries by leveraging MXene modulators to regulate critical electrochemical reaction processes.

High Power Capacity Mechanical RF Switch Using Liquid Metals as Wetted Contacts

High Power Capacity Mechanical RF Switch Using Liquid Metals as Wetted Contacts

Polar Molecule Intercalation to Weaken P2─S Bonding in MnPS3 Toward Ultrahigh-Capacity Sodium Storage.

Layered transition metal trithiophosphates (TMPS3, TM = Mn, Fe, Co, etc.) with high theoretical capacity (>1300 mAh g-1) are potential anode materials for sodium-ion batteries (SIBs). However, the strong bonding between P2 dimers and S atoms in TMPS3 hinders the efficient alloying reaction between P2 dimers and Na+, resulting in practical capacities much lower than theoretical values. Herein, a polar molecule diisopropylamine (DIPA) is intercalated into MnPS3 for the first time to improve the sodium storage performance effectively. Theoretical calculations show that the electron transfer between DIPA and MnPS3 induces more delocalized S p states and weaker P─S bonds, significantly enhancing the electrochemical activity and sodiation/desodiation reaction kinetics. Moreover, the expanded interlayer spacing from 6.48 to 10.75 Å enables faster Na+ diffusion and more active sites for Na+ adsorption. As expected, the DIPA-MnPS3 exhibits an ultrahigh capacity of 1,023 mAh g-1 at 0.2 A g-1 and excellent cycling performance (≈100% capacity retention after 4200 cycles at 10 A g-1), far outperforming those metal thiophosphates anodes reported for SIBs. Interestingly, in situ and ex situ characterizations reveal a quasi-topological intercalation mechanism of DIPA-MnPS3. This work provides a novel strategy for the design of high-performance anode materials for SIBs.

The Problematic Issues of Unmanned Aerial Vehicle Application in Agriculture

The current rapid development of unmanned aviation is largely driven by the needs of the defense-industrial complex. In light of these events, the Russian industry has currently focused its attention on the development of unmanned aerial vehicles characterized by high payload capacity, autonomous flight range, and navigation precision. Considering the projected increase in the production rates of UAVs and the expansion of their functionalities, there is a pressing need for their active integration into various sectors of the economy, including agriculture. Despite the fact that the application of aerial agro-drones, like other aircraft, is regulated by the "Federal Rules for the Use of Airspace of the Russian Federation" (Government Resolution No. 138 dated March 11, 2010), there are currently no unified regulated approaches and requirements for the operation of unmanned aerial vehicles in agriculture. Given the growing relevance of issues related to the integration of unmanned aerial vehicles into agriculture, there is an increased need for the development of documents that regulate the use of agrochemicals for the treatment of agricultural land using these devices. The research objective if the development of a protocol for the inclusion of pesticides if the catalog approved for use through unmanned aerial vehicles.

Advanced single-cell and spatial analysis with high-multiplex characterization of circulating tumor cells and tumor tissue in prostate cancer: Unveiling resistance mechanisms with the CoDuCo in situ assay.

Metastatic prostate cancer is a highly heterogeneous and dynamic disease and practicable tools for patient stratification and resistance monitoring are urgently needed. Liquid biopsy analysis of circulating tumor cells (CTCs) and circulating tumor DNA are promising, however, comprehensive testing is essential due to diverse mechanisms of resistance. Previously, we demonstrated the utility of mRNA-based in situ padlock probe hybridization for characterizing CTCs. We have developed a novel combinatorial dual-color (CoDuCo) assay for in situ mRNA detection, with enhanced multiplexing capacity, enabling the simultaneous analysis of up to 15 distinct markers. This approach was applied to CTCs, corresponding tumor tissue, cancer cell lines, and peripheral blood mononuclear cells for single-cell and spatial gene expression analysis. Using supervised machine learning, we trained a random forest classifier to identify CTCs. Image analysis and visualization of results was performed using open-source Python libraries, CellProfiler, and TissUUmaps. Our study presents data from multiple prostate cancer patients, demonstrating the CoDuCo assay's ability to visualize diverse resistance mechanisms, such as neuroendocrine differentiation markers (SYP, CHGA, NCAM1) and AR-V7 expression. In addition, druggable targets and predictive markers (PSMA, DLL3, SLFN11) were detected in CTCs and formalin-fixed, paraffin-embedded tissue. The machine learning-based CTC classification achieved high performance, with a recall of 0.76 and a specificity of 0.99. The combination of high multiplex capacity and microscopy-based single-cell analysis is a unique and powerful feature of the CoDuCo in situ assay. This synergy enables the simultaneous identification and characterization of CTCs with epithelial, epithelial-mesenchymal, and neuroendocrine phenotypes, the detection of CTC clusters, the visualization of CTC heterogeneity, as well as the spatial investigation of tumor tissue. This assay holds significant potential as a tool for monitoring dynamic molecular changes associated with drug response and resistance in prostate cancer.

Metal Organic Framework‐Derived Anionic P‐Substitution toward CoNiSe‐P with Excellent Electrochemical Stability for Supercapacitor

AbstractThe regulation of nanostructures and composition can significantly enhance the electrochemical activity and accelerate electrochemical reaction kinetics of electrode material. Herein, metal organic framework(MOF) is used as self‐sacrificing templates to prepare CoNiSe‐P by hydrothermal with following selenylation and phosphorization treatment. Due to the hollow porous structure, rich electrochemical active sites and elements synergistic influence, the obtained CoNiSe‐P electrode shows a high capacity of 838 C g−1, which is much higher than CoNiSe (322 C g−1) and CoNiP (616 C g−1). Furthermore, CoNiSe‐P electrode shows excellent rate characteristic (685 C g−1 at 20 A g−1) and ultrahigh electrochemical stability with capacity retention of 99.6% after 10 000 cycles. More importantly, an asymmetric supercapacitor is assembled with CoNiSe‐P as the positive electrode and nitrogen‐doped porous carbon as the negative electrode delivers an energy density of 42.4 Wh kg−1 at 266.6 W kg−1 and maintains a specific capacitance of 96.8% after 10 000 cycles. Significantly, the asymmetric supercapacitor shows a high energy density up to 21.3 Wh kg−1 at a very high power density of 21.3 kW kg−1, higher than those of previously reported asymmetric supercapacitors.

A Universal Interfacial Reconstruction Strategy Based on Converting Residual Alkali for Sodium Layered Oxide Cathodes: Marvelous Air Stability, Reversible Anion Redox, and Practical Full Cell.

Mn-based layered oxide cathodes have attracted widespread attention due to high capacity and low cost, however, poor air stability, irreversible phase transitions, and slow kinetics inhibit their practical application. Here, we propose a universal interfacial reconstruction strategy based on converting residual alkali to tunnel phase Na0.44MnO2 for addressing the above mentioned issue simultaneously, using O3 NaNi0.4Fe0.2Mn0.4O2@2 mol % Na0.44MnO2 (NaNFM@NMO) as the prototype material. The optimized material exhibits an initial capacity and energy density comparable with lithium-ion batteries. The reversible anionic redox behavior and charge compensation mechanism of NaNFM@NMO were analyzed and verified by soft X-ray absorption spectrum and in situ X-ray absorption spectrum. Due to the intrinsic stability of the tunnel structure, excellent air stability and highly reversible structure evolution of the NaNFM@NMO cathode material are achieved, which are confirmed by contact angle test, rigorous aging test, and in situ X-ray diffraction. More importantly, the NaNFM@NMO cathode demonstrates a great match with the nonpresodiated hard carbon anode and shows excellent electrochemical performance of the full cell. Additionally, such a strategy could be also applied to modify P2-type cathodes, showing superior universality and good prospects in industrialized production. Overall, the proposed strategy could improve air stability while remaining interfacial and bulk stable simultaneously and will open up a whole new field for the optimization of other electrode materials.

Composite Solid-State Electrolyte with Vertical Ion Transport Channels for All-Solid-State Lithium Metal Batteries.

Composite solid electrolytes (CSEs) consisting of polymers and fast ionic conductors are considered a promising strategy for realizing safe rechargeable batteries with high energy density. However, randomly distributed fast ionic conductor fillers in the polymer matrix result in tortuous and discontinuous ion channels, which severely constrains the ion transport capacity and restricts its practical application. Here, CSEs with highly loaded vertical ion transport channels are fabricated by magnetically manipulating the alignment of Li0.35La0.55TiO3 nanowires. The construction of densely packed, vertically aligned ion transport channels can effectively enhance the ion transport capacity of the electrolyte, thereby significantly increasing ionic conductivity. At room temperature (RT), the presented CSE exhibits a remarkable ionic conductivity of up to 2.5 × 10-4 S cm-1. The assembled LiFePO4/Li cell delivers high capacities of 118 mAh g-1 at 5 C at 60°C and a RT capacity of 115 mAh g-1 can be achieved at a charging rate of 0.5 C. This work paves an encouraging avenue for further development of advanced CSEs that favor lithium metal batteries with high energy density and electrochemical performance.

Manganese‐Based Composite‐Structure Cathode Materials for Sustainable Batteries

AbstractManganese‐based cathode materials have garnered extensive interest because of their high capacity, superior energy density, and tunable crystal structures. Despite their cost‐effectiveness, challenges like Mn dissolution and gas evolution originating from the irreversible structural degradation pose risks to stability and prolonged electrochemical behaviors, ultimately constraining their practical applications and market prospects. While the material characteristics and redox mechanisms of Mn‐based cathodes are extensively investigated, a systematic iterative approach to material design that balances performance and application demands remains both necessary and urgent. Recent strategies for enhancing cathode performances emphasize the innovative introduction and customization of composite structures in Mn‐based cathode materials to address the challenges above. This review aims to provide a comprehensive understanding of composite‐structure construction methodologies and offers practical guidelines for effectively designing high‐stability Mn‐based composite‐structure cathode materials. This encompasses the classifications of composite scales, the discussions for the extent of composite‐structure construction inside and outside of the cathode grains, and an exploration of the development potential of these materials, especially for grid‐scale applications.

Grid-Like Structured Sb@DNC Anode by Self-Sacrificial Etching for Fast and Durable Sodium Storage.

Alloying-type materials are promising anodes for sodium storage due to high specific capacities and appropriate redox potentials, but their practical application is impeded by rapid capacity decay from volume change during sodium ion insertion/extraction. Hence, a dual-type N-doped carbon-confined antimony (Sb) nanoparticle (Sb@DNC, where DNC contains an outer N-doped carbon armor and an inner N-doped grid-like carbon skeleton) anode material is fabricated via a self-sacrificial etching strategy to address this challenge. Specifically, the dual-type N-doped carbon matrix can prevent the agglomeration and precipitation of Sb particles, increase a large number of reactive active sites, alleviate severe volume expansion/contraction, and construct a highly interconnected electron/ion transport network. Benefiting from the exquisite structure, the Sb@DNC electrode exhibits excellent cycling stability (2400 cycles at 1.0 A g-1) and astonishing high-rate performance (331.0 mAh g-1 at 10.0 A g-1). Additionally, the state-of-the-art in/ex situ technologies reveals the sodium storage mechanism of the "battery-capacitance dual-mode" and the origin of the ability to withstand continuous volumetric strain for the Sb@DNC electrode. Finally, the derived sodium-ion full cell presents outstanding practical potential. This work emphasizes the great significance of rational structural engineering strategies in the field of alloy-type anode materials for high-performance sodium-ion batteries.

Nucleophilic Sn Seeding and Interface Engineering for Highly Stable Sodium Metal Batteries.

Sodium metal is a promising anode material for energy storage beyond lithium-ion batteries due to its abundance and low cost. However, the uncontrolled growth of dendrites and associated safety concerns have limited the practical application of sodium metal batteries (SMBs). By embedding nucleophilic tin seeds in a free-standing carbon film (FSF), here, an effective solution is developed to stabilize the sodium metal anode. The highly conductive and porous carbon matrix, intimately embedded with abundant Sn seeds (C@Sn), enables remarkably uniform sodium plating, and provides long-term stability for SMBs. Mechanistic studies confirm the formation of an Na─Sn alloy on interface which helps to lower the nucleation barrier for sodium plating. Hence, symmetric sodium cells equipped with C@Sn FSFs can sustain uninterrupted sodium plating and stripping for almost 2600h at a high areal capacity of 4mAhcm-2, achieving an average Coulombic efficiency (CE) of 99.88%. In addition, full cells prepared with commercial Na3V2(PO4)3 cathode and C@Sn-FSFs anode deliver remarkable cycling (90mAhg-1 beyond 1300 cycles at 1C) and excellent rate performance. This ingenious strategy of embedding Sn particles within a carbon matrix offers an overall compelling solution to enhance the longevity of sodium anodes.

Biocompatible nanocomposite hydroxyapatite-based granules with increased specific surface area and bioresorbability for bone regenerative medicine applications.

Hydroxyapatite (HA) granules are frequently used in orthopedics and maxillofacial surgeries to fill bone defects and stimulate the regeneration process. Optimal HA granules should have high biocompatibility, high microporosity and/or mesoporosity, and high specific surface area (SSA), which are essential for their bioabsorbability, high bioactivity (ability to form apatite layer on their surfaces) and good osseointegration with the host tissue. Commercially available HA granules that are sintered at high temperatures (≥ 900°C) are biocompatible but show low porosity and SSA (2-5 m2/g), reduced bioactivity, poor solubility and thereby, low bioabsorbability. HA granules of high microporosity and SSA can be produced by applying low sintering temperatures (below 900°C). Nevertheless, although HA sintered at low temperatures shows significantly higher SSA (10-60 m2/g) and improved bioabsorbability, it also exhibits high ion reactivity and cytotoxicity under in vitro conditions. The latter is due to the presence of reaction by-products. Thus, the aim of this study was to fabricate novel biomaterials in the form of granules, composed of hydroxyapatite nanopowder sintered at a high temperature (1100°C) and a biopolymer matrix: chitosan/agarose or chitosan/β-1,3-glucan (curdlan). It was hypothesized that appropriately selected ingredients would ensure high biocompatibility and microstructural properties comparable to HA sintered at low temperatures. Synthesized granules were subjected to the evaluation of their biological, microstructural, physicochemical, and mechanical properties. The obtained results showed that the developed nanocomposite granules were characterized by a lack of cytotoxicity towards both mouse preosteoblasts and normal human fetal osteoblasts, and supported cell adhesion to their surface. Moreover, produced biomaterials had the ability to induce precipitation of apatite crystals after immersion in simulated body fluid, which, combined with high biocompatibility, should ensure good osseointegration after implantation. Additionally, nanocomposite granules possessed microstructural parameters similar to HA sintered at a low temperature (porosity approx. 50%, SSA approx. 30m²/g), Young's modulus (5-8 GPa) comparable to cancellous bone, and high fluid absorption capacity. Moreover, the nanocomposites were prone to biodegradation under the influence of enzymatic solution and in an acidic environment. Additionally, it was noted that the hydroxyapatite nanoparticles remaining after the physicochemical dissolution of the biomaterial were easily phagocytosed by mouse macrophages, mouse preosteoblasts, and normal human fetal osteoblasts (in vitro studies). The obtained materials show great potential as bone tissue implantation biomaterials with improved bioresorbability. The obtained materials show great potential as bone tissue implantation biomaterials with improved bioresorbability.

Porphyrin-Camptothecin (CPT) Grafted Polyoxazoline Amphiphiles for Tumor Photodynamic-Chemotherapy Combination Treatment.

Porphyrin-based photosensitizers are extensively utilized in the realm of photodynamic therapy, capitalizing on their advantageous optical, chemical, and electronic properties. Nonetheless, their application is often constrained by their pronounced hydrophobicity. Structures with a high load capacity and excellent biocompatibility are preferred options to circumvent this obstacle. Herein, we constructed a novel porphyrin-camptothecin (CPT) polymer, which is composed of amphiphilic oxazoline segments, and the drug monomers containing disulfide bonds are modified on the hydrophobic chain of polyoxazoline. The polyoxazoline-porphyrin-CPT (OPC) polymer can self-assemble into nanoparticles in the aqueous phase, possesses excellent stability, and generates abundant singlet oxygen (1O2) under laser irradiation. Additionally, the OPC nanoparticles exhibit satisfactory biocompatibility and high light toxicity against 4T1 cells. In the microenvironment of the tumor, drugs were released from the OPC nanoparticles owing to the high concentration of GSH, causing direct damage to the tumor cell, achieving the combination of photo-chemotherapy. The findings of this research indicate that polyoxazoline porphyrin demonstrates adaptability as a nanoplatform for cancer treatment.