Journal of Materials Chemistry B最新文献

Emulsion-templated foams have displayed promise as injectable bone grafts; however, the use of a surfactant as an emulsifier resulted in relatively small pores and impedes cell attachment. Hydroxyapatite nanoparticles were explored as an alternative stabilizer to address these limitations. To this end, hydroxyapatite nanoparticles were first modified with myristic acid to generate the appropriate balance of hydrophobicity to stabilize a water-in-oil emulsion of neopentyl glycol diacrylate and 1,4-butanedithiol. In situ surface modification of the resulting foam with hydroxyapatite was confirmed with elemental mapping and transmission electron microscopy. Nanoparticle-stabilized foams displayed improved human mesenchymal stem cell viability (91 ± 5%) over surfactant-stabilized foams (23 ± 11%). Although the pore size was appropriate for bone grafting applications (115 ± 71 μm), the foams lacked the interconnected architecture necessary for cell infiltration. We hypothesized that a co-stabilization approach with both surfactant and nanoparticles could be used to achieve interconnected pores while maintaining improved cell attachment and larger pore sizes. A range of hydroxyapatite nanoparticle and surfactant concentrations were investigated to determine the effects on microarchitecture and cell behavior. By balancing these interactions, a co-stabilized foam was identified that possessed large, interconnected pores (108 ± 67 μm) and improved cell viability and attachment. The co-stabilized foam was then evaluated as an injectable bone graft including network formation, microscale integration with bone, push out strength, and compressive properties. Overall, this work demonstrated that in situ surface modification with nHA improved cell attachment while retaining desirable bone grafting features and injectability.

Many traditional Chinese medicine monomers, such as naringin (NG), can regulate the local immune microenvironment to benefit osteogenesis. However, the rapid release of NG from scaffolds severely influences the osteogenesis-promoting effect. Herein, NG was loaded into mesoporous bioglass (MBG) to achieve sustained release through physical adsorption and the barrier role of mesoporous channels, then MBG loaded with NG was added to poly(L-lactic acid) (PLLA) to fabricate composite scaffolds by selective laser sintering (SLS) technology. The results showed that the NG-MBG/PLLA scaffolds could continuously and slowly release NG for 14 days compared with NG/PLLA scaffolds, and the cumulative release amount for the NG-MBG/PLLA scaffolds was 44.26%. In addition, the NG-MBG/PLLA scaffolds can promote the proliferation and osteogenesis differentiation of mouse bone marrow mesenchymal stem cells (mBMSCs). Meanwhile, the composite scaffolds decreased the reactive oxygen species (ROS) level of RAW264.7 under the stimulation of lipopolysaccharide (LPS) and significantly suppressed interleukin-6 (IL-6) and enhanced arginase-1 (Arg-1) protein expressions. Moreover, calcium nodule and alkaline phosphatase production of mBMSCs in a macrophage-conditioned medium for the NG-MBG/PLLA group also evidently increased compared with the PLLA and MBG/PLLA groups. These NG sustained-release composite scaffolds with osteo-immunomodulation function have great application prospects in the clinic.

Far-red BODIPY-based oxime esters for photo-uncaging were designed to release molecules of interest with carboxylic acids. The low power red LED light breaks the N–O oxime ester bond and frees the caged molecules. We studied the mechanism and kinetics of the uncaging procedure using a ¹H NMR spectrometer. Moreover, the drug delivery strategy to release valproic acid (VPA) on demand was tested in vitro using this far-red BODIPY photo-uncaging strategy to induce apoptosis in tumor cells.

Genetically engineered bacteria (GEB) have shown significant promise to revolutionize modern medicine. These engineered bacteria with unique properties such as enhanced targeting, versatility, biofilm disruption, reduced drug resistance, self-amplification capabilities, and biodegradability represent a highly promising approach for targeted drug delivery and cancer theranostics. This innovative approach involves modifying bacterial strains to function as drug carriers, capable of delivering therapeutic agents directly to specific cells or tissues. Unlike synthetic drug delivery systems, GEB are inherently biodegradable and can be naturally eliminated from the body, reducing potential long-term side effects or complications associated with residual foreign constituents. However, several pivotal challenges such as safety and controllability need to be addressed. Researchers have explored novel tactics to improve their capabilities and overcome existing challenges, including synthetic biology tools (e.g., clustered regularly interspaced short palindromic repeats (CRISPR) and bioinformatics-driven design), microbiome engineering, combination therapies, immune system interaction, and biocontainment strategies. Because of the remarkable advantages and tangible progress in this field, GEB may emerge as vital tools in personalized medicine, providing precise and controlled drug delivery for various diseases (especially cancer). In this context, future directions include the integration of nanotechnology with GEB, the focus on microbiota-targeted therapies, the incorporation of programmable behaviors, the enhancement in immunotherapy treatments, and the discovery of non-medical applications. In this way, careful ethical considerations and regulatory frameworks are necessary for developing GEB-based systems for targeted drug delivery. By addressing safety concerns, ensuring informed consent, promoting equitable access, understanding long-term effects, mitigating dual-use risks, and fostering public engagement, these engineered bacteria can be employed as promising delivery vehicles in bio- and nanomedicine. In this review, recent advances related to the application of GEB in targeted drug delivery and cancer therapy are discussed, covering crucial challenging issues and future perspectives.

A novel self-powered wearable triboelectric biosensor concept is proposed in this paper, which consists of Scotch tape and a metalized polyester sheet (Al/PET). The Scotch tape is the sensing element by exploring the interaction between the tape polypropylene backing material and the acrylic adhesive layer when pressing and releasing. The polypropylene surface only has partial positive charges because of a nonpolar surface, while the acrylic adhesive has a polar surface with positively and negatively charged and neutral regions. Atomic size gaps are formed because of the attractive and repulsive areas at the interface due to van der Waals forces. These density depleted regions act as ‘geometric’ gaps to produce triboelectric charges via contact and separation on a microscopic scale. This leads to our wearable biosensor design for measuring human body motion. Associated skin contraction and relaxation during body motion will activate the contact and separation between the polypropylene and acrylic adhesive layer when the sensor assembly is adhered to the skin. Various demonstrations were conducted to detect different body motions, including elbow flexion at a low angle, forearm protonation, forearm supination, knee flexion/extension, proximal interphalangeal flexion/extension, temple motion due to eye blinking, and temporomandibular opening. Unique features can be identified which are associated with different body motions. Moreover, the measurements from our triboelectric sensor correlate well with the results from a commercial electromyography (EMG) sensor in an isokinetic leg extension test, which leads to a new method of measuring human muscle activation.

Immune checkpoint (ICP) blockade (ICB) is one of the most promising immunotherapies for acute myeloid leukemia (AML). However, owing to their heterogeneity, AML cells may cause uncoordinated metabolic fluxes and heterogeneous immune responses, inducing the release of a spatiotemporally sensitive immune response marker. Timely and in situ detection of immune responses in ICB therapy is important for therapeutic strategy adjustment. Herein, we constructed an all-in-one nanoprobe for self-driving ICB and simultaneously detecting an immune response in the same AML cell in vivo, thus enabling accurate evaluation of heterogenetic immune responses in living AML mice without additional drug treatment or probe processes. The nature-inspire polydopamine (PDA) nanoparticles loaded with an ICP blocker were targeted to the leukocyte immunoglobulin like receptor B4 (a new ICP) of AML cells to induce the release of immune response marker granzyme B (GrB). The PDA nanoparticles were additionally paired with carbon-derived graphene quantum dots (GQDs) to construct a full-organic ‘turn-on’ bionanoprobe that can transfer fluorescence resonance energy for GrB detection. This multifunctional nanoprobe was validated for triggering ICB therapy and monitoring the changes of GrB levels in real-time both in vitro and in vivo. The organic nanoprobe showed excellent permeability and retention in tumor cells and high biocompatibility in vivo. This bionanoprobe orderly interacted with the upstream ICP molecules and downstream signal molecule GrB, thereby achieving in situ immune response signals within the therapeutic efficacy evaluation window.

A nanocomposite of (2-aminoethyl)piperazine ligand substituted with zinc(II) tetra carboxylic acid phthalocyanine (ZnTEPZCAPC) and MWCNTs was constructed and employed to develop an electrochemical sensor with outstanding sensitivity and a low detection limit. The macrocyclic complex ZnTEPZCAPC was first synthesized and then employed for the electrochemical determination of the antipsychotic drug promazine (PMZ). The as-prepared ZnTEPZCAPC and MWCNT nanocomposite was characterized using different techniques, such as Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), UV-visible spectroscopy (UV-Vis), field emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA). Further, the prepared ZnTEPZCAPC@MWCNT nanocomposites were modified on a glassy carbon electrode (GCE) surface, and the electrochemical activity was investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA) tests in pH 7.0 phosphate buffer solution (PBS) in the potential window of 0.0–1 V. The ZnTEPZCAPC@MWCNTs displayed a superior electrochemical performance because of their high electrochemical active surface area (0.453 cm²), good conductivity, and a synergetic effect. The developed electrochemical sensor exhibited a broad linear range of 0.05–635 μM and the lowest detection limit of 0.0125 nM, as well as excellent sensitivity, repeatability, and reproducibility. Finally, the fabricated sensor was successively used for the real-time detection of PMZ in environmental and biological samples and displayed feasible recoveries.

3D printing of titanium (Ti) metal has potential to transform the field of personalised orthopaedics and dental implants. However, the impacts of controlled surface topographical features of 3D printed Ti implants on their interactions with the cellular microenvironment and incorporation of biological growth factors, which are critical in guiding the integration of implants with bone, are not well studied. In the present study, we explore the role of surface topological features of 3D printed Ti implants using an anodised titania nanotube (TiNT) surface layer in guiding their immune cell interaction and ability to deliver bioactive form of growth factors. TiNT layers with precisely controlled pore diameter (between 21and 130 nm) were anodically grown on 3D printed Ti surfaces to impart a nano–micro rough topology. Immune biomarker profiles at gene and protein levels show that anodised 3D Ti surfaces with smaller pores resulted in classical activation of macrophages (M1-like), while larger pores (i.e., >100 nm) promoted alternate activation of macrophages (M2-like). The in vitro bone mineralisation studies using the conditioned media from the immunomodulatory studies elucidate a clear impact of pore diameter on bone mineralisation. The tubular structure of TiNTs was utilised as a container to incorporate recombinant human bone morphogenetic protein-2 (BMP-2) in the presence of various sugar and polymeric cryoprotectants. Sucrose offered the most sustainable release of preserved BMP-2 from TiNTs. Downstream effects of released BMP-2 on macrophages as well as bone mineralisation were assessed showing bioactivity retention of the released rhBMP-2. Overall, the TiNT surface topography in combination with controlled, sustained, and local release of bioactive growth factors can potentially enhance the osseointegration outcomes of custom 3D printed Ti implants in the clinic.

Early detection of cancer is essential for successful treatment and improvement in patient prognosis. Deregulation of post-translational modifications (PTMs) of proteins, especially phosphorylation, is present in many types of cancer. Therefore, the development of materials for the rapid sensing of low abundant phosphorylated peptides in biological samples can be of great therapeutic value. In this work, we have synthesised fluorescent molecularly imprinted polymers (fMIPs) for the detection of the phosphorylated tyrosine epitope of ZAP70, a cancer biomarker. The polymers were grafted as nanometer-thin shells from functionalised submicron-sized silica particles using a reversible addition-fragmentation chain-transfer (RAFT) polymerisation. Employing the combination of fluorescent urea and intrinsically cationic bis-imidazolium receptor cross-linkers, we have developed fluorescent sensory particles, showing an imprinting factor (IF) of 5.0. The imprinted polymer can successfully distinguish between phosphorylated and non-phosphorylated tripeptides, reaching lower micromolar sensitivity in organic solvents and specifically capture unprotected peptide complements in a neutral buffer. Additionally, we have shown the importance of assessing the influence of counterions present in the MIP system on the imprinting process and final material performance. The potential drawbacks of using epitopes with protective groups, which can co-imprint with targeted functionality, are also discussed.

We demonstrate a new strategy of PEGylation over core–shell MOFs of HKUST-1 and Cu-MOF-2 by a solvothermal method. The novel synthesized PEGylated core–shell MOFs has synergistic enhancement in terms of physicochemical and biological properties. FTIR spectroscopy and XRD analysis described the bonding characteristics of the double-shelled–core MOFs PEG@HKUST-1@CuMOF-2 and PEG@CuMOF-2@HKUST-1. XPS and EDAX spectroscopy confirmed the structural features of the PEG@core–shell MOFs. The as-synthesized PEG-modified core–shell MOFs showed a readily identifiable morphology with a reduction in particle size. The significant observation from SEM and TEM was that agglomeration disappeared completely, and the morphology of individual core–shell MOFs was clearly revealed. BET analysis provided the surface characteristics of MOF compounds. The chemical states of frameworks were established by XPS. The designed PEG-modified copper MOFs were evaluated for their activity against Gram-positive (Staphylococcus aureus, Enterococcus faecalis), Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacterial species and activity against fungal species (Aspergillus niger and Candida albicans). This research work highlights a facile and synergistic approach to design promising biocompatible nano-dimensional core–shell MOFs for biological applications.