RSC Advances

Gambrill, Benjamin; Yang, Lirong; Prokopovich, Polina

doi: 10.1039/d5ra09258bpmid: 41959548

Injectable hydrogels have the ability to bridge sites of bone fractures, favouring bone regeneration processes such as osteoinduction followed by osteoconduction, thereby restoring bone functions in terms of structural stability and support. The ideal material would also prevent the development of infections. Osteoinductive, osteoconductive, and antimicrobial hydrogels have not been developed yet. A hydrogel was prepared using poly(ethylene glycol) methyl ether methacrylate and 2-(dimethylamino)ethyl methacrylate, with bis[2-(methacryloyloxy)ethyl] phosphate as a crosslinker; dexamethasone and Sr and Zn ions were also incorporated. Dexamethasone and Sr and Zn ions were added into the hydrogel to encourage both bone regeneration and provide an antibacterial component, given the osteogenic/antimicrobial properties of these chemicals. The hydrogels were formulated using a crosslinker to create a rigid hydrogel capable of supporting bone regeneration while releasing the incorporated chemicals. Hydrogel polymerisation was characterised by pH and temperature changes. Hydrogel elasticity, stiffness, and viscosity were tested using a frequency sweep. The release of Sr and Zn ions and dexamethasone from hydrogels with different levels of crosslinker was also measured. The presence of hydroxyapatite, its deposition by osteoblasts and their growth, and the presence of osteocalcin were determined. The antibacterial effects were tested using Staphylococcus epidermidis and methicillin-resistant Staphylococcus aureus (MRSA). The results indicate that hydrogel swelling and changes in pH, temperature, and storage/loss modulus were favourable for the functional hydrogel, which could be injected at the fracture site. Osteoblast growth and hydroxyapatite formation were favoured by lower crosslinker concentrations, possibly influenced by the diffusion of Sr and Zn ions and dexamethasone through the hydrogel, while general cell viability was favoured by higher crosslinker concentrations. A slight antibacterial effect was observed for Sr- and Zn-releasing hydrogels compared to the standard hydrogel. The prepared hydrogel shows suitability as a material to bridge fracture sites while supporting osteoinduction in the presence of hydroxyapatite and osteocalcin and has the ability to prevent fracture-associated infections.

Tiwari, Harshita; Singh, Swati; Kumari, Vandana; Tripathi, Shikha; Singh, Anurag Kumar; Parmar, Avanish Singh; Singh, Santosh Kumar; Gautam, Vibhav

doi: 10.1039/d5ra08838kpmid: 41959547

Cancer is one of the leading causes of mortality all across the world, and the clinical applications of numerous chemotherapeutic agents are limited by major side effects. Among these, methotrexate (MTX) is a widely used anticancer drug which exhibits certain limitations related to biocompatibility and solubility. Therefore, to address these limitations, MTX was covalently conjugated to multi-walled carbon nanotubes (MWCNTs) to develop a stable and targeted nanotherapeutic system. MWCNTs were first subjected to purification followed by carboxylation which was validated through dispersion solubility test. MTX-MWCNT was then subjected to characterization to validate successful conjugation after which the cytotoxic potential of MTX-MWCNT was assessed by cell viability assay on MCF-7 (hormone-positive breast cancer), MDA-MB 231 (triple-negative breast cancer), and HeLa (cervical cancer) cells. The evaluation of safety profile and hemocompatibility was done using non-cancerous HEK 293T (human embryonic kidney) cells and in vitro hemolysis assay respectively. The cytotoxic potential of MTX-MWCNT was assessed through cell viability assay which demonstrated a dose-dependent reduction in cancer cell viability after treatment with MTX-MWCNTs with minimal toxicity toward normal cells and blood. The anti-angiogenic potential of MTX-MWCNT was also tested further through ex vivo chick chorioallantoic membrane (CAM) assay which revealed significant reduction in vessel branching. The cytotoxic activity of MTX-MWCNT was also confirmed by biochemical assays, including cell proliferation assay, glucose estimation assay, and total antioxidant status (TAS). Moreover, the cytotoxic potential of MTX-MWCNT was further assessed at the gene level through quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis which demonstrated upregulation of the pro-apoptotic BAX gene and downregulation of the anti-apoptotic BCL-2 gene. Furthermore, kit-based enzyme-linked immunosorbent assay (ELISA) quantification further confirmed increased BAX, decreased BCL-2, and reduced telomerase protein expression. Lastly, the alteration in nuclear morphology in all three cancer cells post treatment with MTX-MWCNTs was evaluated through 4′,6-diamidino-2-phenylindole (DAPI) staining followed by fluorescence microscopy. Collectively, the obtained findings highlight that MTX-MWCNT efficiently induces apoptosis and inhibits angiogenesis while maintaining significant biosafety, establishing it as an emerging nanoscale platform for targeted cancer therapy.

Ben Ayed, Amina; Ulusoy, Songül; Ulusoy, Halil İbrahim; Polat, Ümmügülsüm; Khemakhem, Hamadi

doi: 10.1039/d5ra09942kpmid: 41969385

The analysis of drug molecules in biological samples is a challenge for method development studies. The existence of matrix components and trace concentrations of target molecules in the samples make this analysis more difficult. Sample pre-treatment procedures, such as solid-phase micro extraction (SPME), facilitate and make this analysis possible using conventional analytical techniques such as HPLC. A newly synthesized trimesic acid (TMA)-modified magnetic adsorbent, Fe3O4@SiO2–TMA, effectively retained drug molecules, enabling the successful determination of bifonazole (BFZ) and itraconazole (ITZ) residues in model solutions, including artificial saliva and urine samples. The characterization of the new adsorbent was performed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Raman spectroscopy. The linear ranges for both target molecules were 15.00–1000.00 ng mL−1 (R2 > 0.9954), with a limit of detection lower than 5.00 ng mL−1. The accuracy and repeatability of the proposed method were determined as recovery (R%) and relative standard deviation (RSD%) using spiked samples. This study presented the synthesis and characterization of Fe3O4@SiO2–TMA, a new magnetic adsorbent, for the accurate and precise analysis of BFZ and ITZ, known as antifungal molecules, in biological samples. A straightforward and efficient determination of the target compounds was achieved using a magnetic solid-phase extraction (MSPE) procedure coupled with a high-performance liquid chromatography system equipped with a diode array detector (HPLC-DAD). The greenness and practical applicability of the method were assessed using BAGI and MoGAPI tools, with scores of 65 and 76, respectively. The developed method was successfully applied to real biological samples, yielding recovery values between 94.7% and 107.5%. These results demonstrate that the proposed approach is sensitive, reliable, and environmentally sustainable for routine antifungal drug analysis.

Oladipo, Segun D.; Adeleke, Adesola A.; Olofisan, Kolawole A.; Omondi, Bernard; Luckay, Robert C.

doi: 10.1039/d6ra01650bpmid: 41969390

Six new copper(ii) complexes with general molecular formula [CuL1(Phen)] (1), [CuL2(Phen)] (2), [CuL3(Phen)] (3), [CuL1(DM-Phen)] (4), [CuL2(DM-Phen)] (5) and [CuL3(DM-Phen)] (6) (L = (E)-1-(((4-chloro-2-hydroxyphenyl)imino)methyl)naphthalen-2-ol (L1), (E)-1-(((2-hydroxy-5-methylphenyl)imino)methyl)naphthalen-2-ol (L2), (E)-1-(((2-hydroxy-4-nitrophenyl)imino)methyl)naphthalen-2-ol (L3), Phen = 1,10-phenanthroline and DM-Phen = 2,9-dimethyl-1,10-phenanthroline) have been synthesized and characterized by spectroscopic as well as crystallographic techniques. Molecular structures of 2, 4, 5 and 6 revealed that they are mononuclear species where the copper(ii) center is five-coordinated to a pair of oxygen atoms as well as one nitrogen atom from the ligands (L1–L3) and to a pair of nitrogen atoms from the auxiliary ligand (Phen or DM-Phen) conforming to a distorted square pyramid. The binding affinities of ligands L1–L3 and copper(ii) complexes 1–6 with calf thymus DNA (ctDNA) and bovine serum albumin (BSA) were evaluated using UV-visible absorption spectroscopy. For ctDNA, all compounds showed hypochromism and bathochromic shifts suggesting intercalative binding, with Kb values ranging from 1.49 × 104 to 2.74 × 105 M−1. The complexes exhibited 3–18-fold higher affinity than ligands, especially those with 2,9-dimethyl-1,10-phenanthroline coligands. BSA titrations of complexes 1–6 revealed hyperchromic shifts at ∼280 nm, with Kb values of 9.59 × 104 to 2.41 × 105 M−1. These moderate-to-strong bindings were enhanced by lipophilic substituents that promote hydrophobic and π-stacking interactions in protein pockets. All of the compounds inhibit α-amylase better than acarbose with complex 5 (IC50 = 0.274 mM) showing the highest activity. For the α-glucosidase assay, only complexes 2 (IC50 = 0.055 mM) and 4 (IC50 = 0.054 mM) outshined acarbose (IC50 = 0.059 mM) while other compounds showed moderate to good α-glucosidase inhibition activity. Antioxidant activities of the free ligands showed better activity than that of the metal complexes with none of the compounds performing better than quercetin in all of the assays explored for this study.

Kim, Dong Hyun; Choi, Yoon-Seok; Seo, Han-Jin; Shin, Seoung-Soo; Woo, Jong-Yeon; Park, Seung-Jin; Seo, Dae-Shik

doi: 10.1039/d6ra00107fpmid: 41959542

High-performance liquid crystal (LC) alignment layers are essential for optimizing the electro-optic properties of advanced display and photonic devices. While conventional rubbing processes are widely used, they face limitations such as physical contact damage and static electricity. In this study, we present a robust non-contact alignment method by transferring one-dimensional nanopatterns onto an ultraviolet-responsive polymer and a BiTiO hybrid film using ultraviolet nanoimprint lithography (UV-NIL). The effects of UV curing time (2, 4, and 6 min) on the morphological stability and surface modification of the films were systematically analyzed to verify their performance as LC alignment layers. Our results demonstrate that LC cells fabricated with BiTiO hybrid thin films cured for 4 min achieved superior homogeneous alignment, as confirmed by polarized optical microscopy (POM) and pretilt angle measurements. Atomic force microscopy (AFM) revealed that the optimal curing time is critical for the formation of well-defined nanopatterns. Furthermore, the developed films exhibited a high average anchoring energy of 1.9 × 10−4, which is comparable to conventional alignment methods. These findings highlight the potential of nanopatterned hybrid thin films as a highly efficient and stable alternative for next-generation LC alignment applications.

Pinchuk, Nataliia D.; Piecuch, Agata; Sobierajska, Paulina; Latvis, Cole; Szyszka, Katarzyna; Targonska, Sara; Bezkrovnyi, Oleksii; Ogórek, Rafał; Wang, Yadong; Wiglusz, Rafal J.

doi: 10.1039/d6ra01471bpmid: 41959544

Copper- and silicate-containing hydroxyapatites have attracted increasing attention as potential antimicrobial biomaterials. This paper aims to synthesize nanosized hydroxyapatite-type materials doped with copper(ii) ions alone (nHAp: Cu2+) and with orthosilicate groups (Si-nHAp: Cu2+) via a microwave-assisted hydrothermal method followed by sintering at 450 °C. Copper(ii) ions were incorporated at the concentrations of 0.1, 0.5, and 1 mol%, while orthosilicate substitution replaced one orthophosphate group in the hydroxyapatite structure. This study focuses on the synergistic influence of cationic (Cu2+) and anionic (SiO44−) substitutions on the composition, morphological features, ion-release behaviour, and biological activity of nanosized apatite materials. We used a wide range of characterization methods and demonstrated both morphological changes of doped hydroxyapatite nanoparticles and selective antimicrobial activity against Gram-positive bacteria. No effects on Gram-negative bacteria or fungi were observed. Silicate ions increase the release of Cu2+ ions from 56% to 98%, thereby enhancing the reduction of Gram-positive bacteria growth. At lower concentrations, the materials showed no cytotoxic effect. Our work clearly shows that synthesized materials with low dopant content exhibit selective antimicrobial activity and can be used to treat infections, targeting Gram-positive bacteria such as S. epidermidis, S. aureus, and E. faecalis.

Sprengel, Carla; Fischer, Ute; Borkhardt, Arndt; Haas, Rainer; Heinzel, Thomas

doi: 10.1039/d6ra01285jpmid: 41959546

Brain organoids are exposed during their growth to fluorescent carbon nanodots (CNDs). We observe that the CNDs penetrate through the whole organoid in all maturation stages and are taken up by viable cells irrespective of their type and location, most likely by endocytosis. They remain inside the cells after enzymatic dissociation of the organoids. No influence of the CNDs on the organoids' viability after 48 h exposure during the first 15 weeks could be detected. Our results suggest that CNDs are interesting candidates for multifunctional fluorescent labeling in organoid research and development, such as structural imaging or drug screening.

Sheykhan, Nafiseh; Ghashang, Majid; Szuławska-Mroczek, Agata

doi: 10.1039/d5ra09022apmid: 41969392

A novel biofunctionalized polymeric adsorbent, Chitosan-Polyethyleneimine-Metallothionein-like Proteins (Chitosan-PEI-MTLPs), was synthesized through a controlled multi-step grafting and immobilization strategy. Mechanical analysis revealed a substantial enhancement in mechanical integrity following PEI grafting and MTLP conjugation, with the flexural strength (FS) increasing from 25.48 MPa (chitosan) to 68.75 MPa (Chitosan-PEI-MTLPs), and compressive strength (CS) rising from 51.25 MPa to 129.35 MPa. Water absorption increased from 19.9% to 32%, indicating improved hydrophilicity and porosity. The synthesized biocomposite demonstrated exceptional adsorption performance for Cd(ii), Ni(ii), and Pb(ii) ions, achieving maximum removal efficiencies of 93%, 89%, and 95%, respectively, at pH 6.5 and 45 °C. Kinetic studies confirmed a pseudo-first-order model, suggesting a predominantly physical adsorption process. Reusability tests demonstrated excellent regeneration capability, with 89–91% capacity retention after eleven cycles. These findings establish the Chitosan-PEI-MTLPs polymer as a highly stable, reusable, and biocompatible adsorbent with potential for selective heavy metal remediation in aqueous systems.

Wang, Tongtong; Patyal, Soni; Naushad, Mu.; Dhiman, Pooja; Sharma, Gaurav; Gao, Ying; Wang, Sen; Li, Weiqian; Cai, Jinjun

doi: 10.1039/d5ra09740apmid: 41959545

Human-driven activities related to diverse industries such as textiles, pharmaceuticals, plastics, leather, and agriculture contribute significantly to the discharge of pollutants into aquatic environments, thereby threatening the ecological balance and posing a risk to living organisms. Over the past few years, algae have been acknowledged as a cost-effective and sustainable resource for the detoxification of harmful pollutants, primarily through mechanisms such as intracellular biodegradation, bioaccumulation, and biosorption. Besides the direct involvement of algae in the removal of pollutants, they can be converted into carbon-rich materials such as hydrochar, biochar, and activated carbon. These materials possess high specific surface areas and different functional groups, which make them quite effective for the adsorption of organic pollutants in wastewater treatment. Algal-derived adsorbents exhibit high adsorption efficiency because of the synergistic effects of various interactions, including electrostatic forces, hydrogen bonding, π–π interactions, and pore filling effects, all of which depend on the engineered surface functional groups and porous structure of algae-derived carbon-rich materials. This review uniquely explores various algal species for the preparation of adsorbents and also examines the modification methods used to convert algae into adsorbents. It examines their effectiveness in the removal of organic contaminants from water systems. Future research needs to bridge the gap between laboratory-scale and real-world applications, especially through pilot-scale studies in real wastewater and comprehensive life-cycle assessments.

Fu, Hexin; Zhao, Lu; Tang, Dong

doi: 10.1039/d6ra90036dpmid: 41959549

Correction for ‘The application of ICG-based photodynamic therapy combined with nanotechnology in tumor treatment’ by Hexin Fu et al., RSC Adv., 2026, 16, 7204–7220, https://doi.org/10.1039/D5RA08557H.