Protein Corona-Directed Cellular Recognition and Uptake of Polyethylene Nanoplastics by Macrophages.

The widespread use of plastic products in daily life has raised concerns about the health hazards associated with nanoplastics (NPs). When exposed, NPs are likely to infiltrate the bloodstream, interact with plasma proteins, and trigger macrophage recognition and clearance. In this study, we focused on establishing a correlation between the unique protein coronal signatures of high-density (HDPE) and low-density (LDPE) polyethylene (PE) NPs with their ultimate impact on macrophage recognition and cytotoxicity. We observed that low-density and high-density lipoprotein receptors (LDLR and SR-B1), facilitated by apolipoproteins, played an essential role in PE-NP recognition. Consequently, PE-NPs activated the caspase-3/GSDME pathway and ultimately led to pyroptosis. Advanced imaging techniques, including label-free scattered light confocal imaging and cryo-soft X-ray transmission microscopy with 3D-tomographic reconstruction (nano-CT), provided powerful insights into visualizing NPs-cell interactions. These findings underscore the potential risks of NPs to macrophages and introduce analytical methods for studying the behavior of NPs in biological systems.

Root canals shaped by nickel-titanium instrumentation with automated computerized numerical control systems.

BACKGROUND: To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping. METHODS: The movement of the automated device and the insertion angle were investigated. In Experiment 1, simulated resin root canals were randomly divided into four groups (n = 20): manual downward movement using a handpiece (Group 1), vertical downward movement by CNC (Group 2), reciprocating up and down movement by CNC (Group 3), and spiral up and down movement by CNC (Group 4). In Experiment 2, five different insertion angles of the NiTi file were evaluated (n = 20). Four parameters were used to evaluate the shaping ability: change in the working length, central axis offset, curvature variation, and preparation time. Groups were compared using one-way analysis of variance (ANOVA) with significance was set at P < 0.05. RESULTS: The change in central axis position in the curved part of the root canal was found to be smaller in Group 4 than in other groups (P < 0.05). The curvature changes and preparation time of Groups 1 and 4 were significantly reduced compared with Groups 2 and 3 (P < 0.05). The variation in working length and curvature in the 5° insertion angle group was significantly smaller than in the other groups (P < 0.05). CONCLUSIONS: A spiral up and down movement, controlled by the CNC machine, and 5° insertion angle, maintained original root canal shape more precisely than other methods.

A Clinical Application Study of Mixed Reality Technology Assisted Lumbar Pedicle Screws Implantation.

BACKGROUND This was a prospective comparative study of mixed reality (MR) technology assisted lumbar pedicle screws placement and traditional lumbar pedicle screws placement. MATERIAL AND METHODS Fifty cases of lumbar pedicle screws placement were randomly divided into 2 groups: 25 cases with MR technology in group A, and 25 cases without MR technology in group B. All patients had their scores on the Oswestry disability index (ODI) of low back pain and the visual analog scale (VAS) of the affected lower limb recorded at pre-operation. Blood loss, operative duration, success rate of first penetration by tap, and number of times C-arm fluoroscopy was performed were recorded at intraoperation. The postoperative drainage was recorded. The ODI of low back pain and VAS of the affected lower limb were recorded at 1, 3, and 6 months after operation. RESULTS Group A had less bleeding, shorter operation time, higher success rate of first penetration by tap, and fewer times using C-arm fluoroscopy at intraoperation (P<0.05). There was significant difference in ODI scores and VAS scores at 1 mouth after operation (P<0.05). The postoperative drainage of group A was less than group B (P<0.05). The implantation accuracy of group A was higher than group B (P<0.05). The postoperative recovery rate of low back pain of group A was faster than group B (P<0.05). CONCLUSIONS The safety of spinal surgery and implantation accuracy of pedicle screw fixation system could be increased by MR technology.

Nanoparticles Based on Poly (ß-Amino Ester) and HPV16-Targeting CRISPR/shRNA as Potential Drugs for HPV16-Related Cervical Malignancy.

Persistent high-risk HPV infection is the main cause of cervical cancer. The HPV oncogene E7 plays an important role in HPV carcinogenesis. Currently, HPV vaccines do not offer an effective treatment for women who already present with cervical disease, and recommended periodical cervical screenings are difficult to perform in countries and areas lacking medical resources. Our aim was to develop nanoparticles (NPs) based on poly (ß-amino ester) (PBAE) and HPV16 E7-targeting CRISPR/short hairpin RNA (shRNA) to reduce the levels of HPV16 E7 as a preliminary form of a drug to treat HPV infection and its related cervical malignancy. Our NPs showed low toxicity in cells and mouse organs. By reducing the expression of HPV16 E7, our NPs could inhibit the growth of cervical cancer cells and xenograft tumors in nude mice, and they could reverse the malignant cervical epithelium phenotype in HPV16 transgenic mice. The performance of NPs containing shRNA is better than that of NPs containing CRISPR. HPV-targeting NPs consisting of PBAE and CRISPR/shRNA could potentially be developed as drugs to treat HPV infection and HPV-related cervical malignancy.

Lithium Chloride-Releasing 3D Printed Scaffold for Enhanced Cartilage Regeneration.

BACKGROUND We synthetized a 3D printed poly-ε-caprolactone (PCL) scaffold with polydopamine (PDA) coating and lithium chloride (LiCl) deposition for cartilage tissue engineering and analyzed its effect on promoting rabbit bone marrow mesenchymal stem cells (rBMSC) chondrogenesis in vitro. MATERIAL AND METHODS PCL scaffolds were prepared by 3D printing with a well-designed CAD digital model, then modified by PDA coating to produce PCL-PDA scaffolds. Finally, LiCl was deposited on the PDA coating to produce PCL-PDA-Li scaffolds. The physicochemical properties, bioactivity, and biocompatibility of PCL-PDA-Li scaffolds were accessed by comparing them with PCL scaffolds and PCL-PDA scaffolds. RESULTS 3D PCL scaffolds exhibited excellent mechanical integrity as designed. PDA coating and LiCl deposition improved surface hydrophilicity without sacrificing mechanical strength. Li⁺ release was durable and ion concentration did not reach the cytotoxicity level. This in vitro study showed that, compared to PCL scaffolds, PCL-PDA and PCL-PDA-Li scaffolds significantly increased glycosaminoglycan (GAG) formation and chondrogenic marker gene expression, while PCL-PDA-Li scaffolds showed far higher rBMSC viability and chondrogenesis. CONCLUSIONS 3D printed PCL-PDA-Li scaffolds promoted chondrogenesis in vitro and may provide a good method for lithium administration and be a potential candidate for cartilage tissue engineering.

An effective and biocompatible polyethylenimine based vaginal suppository for gene delivery.

Gene therapy targeted human papillomavirus (HPV) is a promising treatment for cervical cancer, and the key for clinical application depends on an effective gene delivery method. Our aim was to formulate a new pharmaceutical formula for appropriate gene delivery intravaginally. For the first time, we here developed a new polyethylenimine (PEI) based vaginal suppository. The sectional immunofluorescence results confirmed the delivery efficacy both in vivo and in vitro. The quenching fluorescence and decreased gene expression in topical epithelium of green fluorescence protein (GFP) transgenic mice demonstrated the efficient targeting potential of the suppository. The other aim of this study was to evaluate the biocompatibility of the PEI based transfer. To our knowledge, this was also the first study to explore the toxicity in vivo systematically and comprehensively. Our study provided novel ideas for the translational application of PEI based suppository to the prevention and treatment of cervical cancer.

Antimicrobial Activity of 3D-Printed Poly(ε-Caprolactone) (PCL) Composite Scaffolds Presenting Vancomycin-Loaded Polylactic Acid-Glycolic Acid (PLGA) Microspheres.

BACKGROUND The aim of this study was to design and test a novel composite scaffold with antibacterial efficacy for treating bone infections using a three-dimensional (3D) printed poly(ε-caprolactone) (PCL) scaffold coated with polydopamine (PDA) for the adsorption of polylactic acid-glycolic acid (PLGA) microspheres loaded with vancomycin. MATERIAL AND METHODS Vancomycin-loaded PLGA microspheres were produced by the double-emulsion method, and microsphere morphology, drug-loading dosage, encapsulation efficiency, average diameter, and release characteristics were examined. Composite scaffolds were prepared by adsorption of the microspheres on PDA-coated, 3D-printed PCL scaffolds, and scaffold morphology, biocompatibility, vancomycin release, and antibacterial efficacy were evaluated. RESULTS The vancomycin-loaded microspheres were smooth, round, uniform in size, and had no adhesion phenomenon, and exhibited sustained release of vancomycin from the microspheres for more than 4 weeks. Upon modification with PDA, the PCL scaffold changed from white to black, and after microsphere adsorption, dot-like white particles were seen. On scanning electron microscopy, PDA particles were observed on the PCL/PDA composite scaffolds, and PLGA microspheres were evenly dispersed over the PDA coating on the PCL/PDA/PLGA composite scaffolds. Cell viability assays showed that the adhesion and proliferation of rabbit bone mesenchymal stem cells were greater on the PCL/PDA scaffolds than on unmodified PCL scaffolds. Microsphere adsorption had no significant effect on cell proliferation. In vitro release of vancomycin from the composite scaffolds was observed for more than 4 weeks, and observation of the inhibition zone on agar plates of Staphylococcus aureus showed that the scaffolds maintained their antibacterial effect for more than 4 weeks. CONCLUSIONS The 3D-printed, PDA-coated PCL scaffold carrying vancomycin-loaded PLGA microspheres exhibited good biocompatibility and a sustained antibacterial effect in vitro.

Pathophysiologic mechanisms of biomedical nanomaterials.

Nanomaterials (NMs) have been widespread used in biomedical fields, daily consuming, and even food industry. It is crucial to understand the safety and biomedical efficacy of NMs. In this review, we summarized the recent progress about the physiological and pathological effects of NMs from several levels: protein-nano interface, NM-subcellular structures, and cell-cell interaction. We focused on the detailed information of nano-bio interaction, especially about protein adsorption, intracellular trafficking, biological barriers, and signaling pathways as well as the associated mechanism mediated by nanomaterials. We also introduced related analytical methods that are meaningful and helpful for biomedical effect studies in the future. We believe that knowledge about pathophysiologic effects of NMs is not only significant for rational design of medical NMs but also helps predict their safety and further improve their applications in the future.

Resveratrol ameliorates experimental periodontitis in diabetic mice through negative regulation of TLR4 signaling.

AIM: To investigate the therapeutic effects of resveratrol (RSV) on periodontitis in diabetic mice and to explore the underlying mechanisms in vitro. METHODS: Experimental periodontitis was induced in db/db mice by ligature application of porphyromonas gingivalis. The mice were treated with RSV (20 mg/kg, p.o.) daily for 4 weeks. Alveolar bone loss, proinflammatory cytokines and TLR4 expression in the gingival tissue were measured. Cultured gingival epithelial cells (GECs) were used for in vitro studies. The transcriptional activity of TLR4 downstream signaling was analyzed using Western blotting. RESULTS: RSV administration significantly decreased the blood glucose levels, and ameliorated alveolar bone loss in db/db mice with experimental periodontitis. RSV administration also suppressed the high levels of IL-1ß, IL-6, IL-8, TNF-α, and TLR4 in gingival tissue of the mice. In the GECs incubated in high glucose medium, TLR4 expression was substantially upregulated, which was partly blocked in the presence of RSV. Lipopolysaccharides markedly increased the expression and secretion of IL-1ß, IL-6, IL-8, and TNF-α in the GECs cultured in high glucose medium, which was also partly blocked in the presence of RSV. Furthermore, RSV significantly suppressed the phosphorylation of TLR4 downstream factors NF-κB p65, p38MAPK, and STAT3. CONCLUSION: RSV exerts protective effects against experimental periodontitis in db/db mice via negative regulation of TLR4 signaling.

Design, construction and mechanical testing of digital 3D anatomical data-based PCL-HA bone tissue engineering scaffold.

The study aims to investigate the techniques of design and construction of CT 3D reconstructional data-based polycaprolactone (PCL)-hydroxyapatite (HA) scaffold. Femoral and lumbar spinal specimens of eight male New Zealand white rabbits were performed CT and laser scanning data-based 3D printing scaffold processing using PCL-HA powder. Each group was performed eight scaffolds. The CAD-based 3D printed porous cylindrical stents were 16 piece × 3 groups, including the orthogonal scaffold, the Pozi-hole scaffold and the triangular hole scaffold. The gross forms, fiber scaffold diameters and porosities of the scaffolds were measured, and the mechanical testing was performed towards eight pieces of the three kinds of cylindrical scaffolds, respectively. The loading force, deformation, maximum-affordable pressure and deformation value were recorded. The pore-connection rate of each scaffold was 100 % within each group, there was no significant difference in the gross parameters and micro-structural parameters of each scaffold when compared with the design values (P > 0.05). There was no significant difference in the loading force, deformation and deformation value under the maximum-affordable pressure of the three different cylinder scaffolds when the load was above 320 N. The combination of CT and CAD reverse technology could accomplish the design and manufacturing of complex bone tissue engineering scaffolds, with no significant difference in the impacts of the microstructures towards the physical properties of different porous scaffolds under large load.

Melt Electrowriting Combined with Fused Deposition Modeling Printing for the Fabrication of Three-Dimensional Biomimetic Scaffolds for Osteotendinous Junction Regeneration.

Purpose: This study aims to explore a novel scaffold for osteotendinous junction regeneration and to preliminarily verify its osteogenic and tenogenic abilities in vitro. Methods: A polycaprolactone (PCL) scaffold with aligned and orthogonal fibers was created using melt electrowriting (MEW) and fused deposition modeling (FDM). The scaffold was coated with Type I collagen, and hydroxyapatite was carefully added to separate the regions intended for bone and tendon regeneration, before being rolled into a cylindrical shape. Human adipose-derived stem cells (hADSCs) were seeded to evaluate viability and differentiation. Scaffold characterization was performed with Scanning Electron Microscope (SEM). Osteogenesis was assessed by alkaline phosphatase (ALP) and Alizarin red staining, while immunostaining and transcription-quantitative polymerase chain reaction (RT-qPCR) evaluated osteogenic and tendogenic markers. Results: Scaffolds were developed in four variations: aligned (A), collagen-coated aligned (A+C), orthogonal (O), and mineral-coated orthogonal (O+M). SEM analysis confirmed surface morphology and energy-dispersive X-ray spectroscopy (EDS) verified mineral coating on O+M types. Hydrophilicity and mechanical properties were optimized in modified scaffolds, with A+C showing increased tensile strength and O+M improved in compression. hADSCs demonstrated good viability and morphology across scaffolds, withO+M scaffolds showing higher cell proliferation and osteogenic potential, and A and A+C scaffolds supporting tenogenic differentiation. Conclusion: This study confirms the potential of a novel PCL scaffold with distinct regions for osteogenic and tenogenic differentiation, supporting the regeneration of osteotendinous junctions in vitro.

Fabric-Enhanced Vascular Graft with Hierarchical Structure for Promoting the Regeneration of Vascular Tissue.

Natural blood vessels have completed functions, including elasticity, compliance, and excellent antithrombotic properties because of their mature structure. To replace damaged blood vessels, vascular grafts should perform these functions by simulating the natural vascular structures. Although the structures of natural blood vessels are thoroughly explored, constructing a small-diameter vascular graft that matches the mechanical and biological properties of natural blood vessels remains a challenge. A hierarchical vascular graft is fabricated by Electrospinning, Braiding, and Thermally induced phase separation (EBT) processes, which could simulate the structure of natural blood vessels. The internal electrospun structure facilitates the adhesion of endothelial cells, thereby accelerating endothelialization. The intermediate PLGA fabric exhibits excellent mechanical properties, which allow it to maintain its shape during long-term transplantation and prevent graft expansion. The external macroporous structure is beneficial for cell growth and infiltration. Blood vessel remodeling aims to combine a structure that promotes tissue regeneration with anti-inflammatory materials. The results in vitro demonstrated that it EBT vascular graft (EBTVG) has matched the mechanical properties, reliable cytocompatibility, and the strongest endothelialization in situ. The results in vitro and replacement of the resected artery in vivo suggest that the EBTVG combines different structural advantages with biomechanical properties and reliable biocompatibility, significantly promoting the stabilization and regeneration of vascular endothelial cells and vascular smooth muscle cells, as well as stabilizing the blood microenvironment.

Screening the phytotoxicity of micro/nanoplastics through non-targeted metallomics with synchrotron radiation X-ray fluorescence and deep learning: Taking micro/nano polyethylene terephthalate as an example.

Microplastics (MPs) and nanoplastics (NPs) are global pollutants with emerging concerns. Methods to predict and screen their toxicity are crucial. Elemental dyshomeostasis can be used to assess toxicity of environmental pollutants. Non-targeted metallomics, combining synchrotron radiation X-ray fluorescence (SRXRF) and machine learning, has successfully differentiated cancer patients from healthy individuals. The whole idea of this work is to screen the phytotoxicity of nano polyethylene terephthalate (nPET) and micro polyethylene terephthalate (mPET) through non-targeted metallomics with SRXRF and deep learning algorithms. Firstly, Seed germination, seedling growth, photosynthetic changes, and antioxidant activity were used to evaluate the toxicity of mPET and nPET. It was showed that nPET, at 10 mg/L, was more toxic to rice seedlings, inhibiting growth and impairing chlorophyll content, MDA content, and SOD activity compared to mPET. Then, rice seedling leaves exposed to nPET or mPET was examined with SRXRF, and the SRXRF data was differentiated with deep learning algorithms. It was showed that the one-dimensional convolutional neural network (1D-CNN) model achieved 98.99% accuracy without data preprocessing in screening mPET and nPET exposure. In all, non-targeted metallomics with SRXRF and 1D-CNN can effectively screen the exposure and phytotoxicity of nPET/mPET and potentially other emerging pollutants. Further research is needed to assess the phytotoxicity of different types of MPs/NPs using non-targeted metallomics.

Preparation of pH-sensitive porous polylactic acid-based medical dressing with self-pumping function.

Excessive exudation from the wound site and the difficulty of determining the state of wound healing can make medical management more difficult and, in extreme cases, lead to wound deterioration. In this study, we fabricated a pH-sensitive colorimetric chronic wound dressing with self-pumping function using electrostatic spinning technology. It consisted of three layers: a polylactic acid-curcumin (PCPLLA) hydrophobic layer, a hydrolyzed polyacrylonitrile (HPAN) transfer layer, and a polyacrylonitrile-purple kale anthocyanin (PAN-PCA) hydrophilic layer. The results showed that the preparation of porous PLLA fiber membrane loaded with 0.2 % Cur was achieved by adjusting the spinning-related parameters, which could ensure that the composite dressing had sufficient anti-inflammatory, antibacterial and antioxidant properties. The HPAN membrane treated with alkali for 30 min had significantly enhanced liquid wetting ability, and the unidirectional transport of liquid could be achieved by simple combination with the 20 um PCPLLA fiber membrane. In addition, the 4 % loaded PCA showed more obvious color difference than the colorimetric membrane. In vivo and ex vivo experiments have demonstrated the potential of multifunctional dressings for the treatment of chronic wounds.

3D-printed antibiotic-loaded bone cement spacers as adjunctive therapy for hip periprosthetic infection after arthroplasty: A clinical assessment.

OBJECTIVE: To explore the effect of three-dimensional (3D) printing to create personalized antibiotic-loaded bone cement (ALBC) spacers to assist in treatment of periprosthetic infection after total hip arthroplasty (THA). METHODS: The data of 40 patients with postoperative infection after THA were analysed retrospectively. The patients were divided into two groups: the 3D-printing group (age 47-78 years, n = 20) and the conventional group (age 57-78 years, n = 20). In stage I surgery, 3D-printed silicone moulds were used to create ALBC spacers for the 3D-printing group, while traditional manual methods were used to create spacers for the conventional group. After the infection was controlled, both groups underwent conventional hip revision surgery (stage II surgery). All patients were evaluated using the Harris Hip Score (HHS) (primary outcome) for hip function. RESULTS: All 40 patients had follow-up data from 3 months after stage I surgery and 12 months after stage II surgery. The intergroup difference in HHS was 11.25 points [97.5% confidence interval (CI) 7.92-14.58; P < 0.01] at 3 months after stage I surgery, and 9.15 points (97.5% CI 4.82-13.48; P < 0.01) at 12 months after stage II surgery. The overall difference between the two groups was 9.55 points (97.5% CI 5.83-13.27; P < 0.01), which was significant (P < 0.05). CONCLUSION: During the follow-up period, the hip function of the 3D-printing group was superior to that of the conventional group following the treatment of infections after THA.

Coarsening of silver nanoparticles in polyelectrolyte multilayers.

In polyelectrolyte multilayer (PEM) films assembled from poly(diallyldimethylammonium chloride) and poly(styrene sulfonate) via the layer-by-layer deposition technique, the counterions were exchanged with silver ions, which were subsequently reduced in situ to produce silver (Ag) nanoparticles. The Ag nanoparticles embedded in the PEMs were found to undergo an interesting coarsening process over time, through which smaller Ag nanoparticles coalesce into larger ones until reaching an equilibrium. The process was investigated by monitoring the localized surface plasmon resonance of the Ag nanoparticles using UV-vis extinction spectroscopy, and the spectral evolution revealed an increase in nanoparticle size with time, a trend in qualitative agreement with theoretical calculation and further confirmed by transmission electron microscopy. The kinetics of the coarsening process and the size of Ag nanoparticles at equilibrium were found to be affected by the PEM structure as well as the temperature and relative humidity the PEM was exposed to, and coalescence was identified to be the mechanism.

Hydrophobization of inorganic oxide surfaces using dimethylsilanediol.

Dimethylsilanediol is a stable crystalline solid that was described in 1953. As the monomer of an important class of commercial products (poly(dimethylsiloxanes)-silicones, PDMS) and as a simple molecule in its own right (the silicon analog of acetone hydrate), it has been neglected by several fields of fundamental and applied research including the hydrophobization of inorganic oxide surfaces. We report that dimethylsilanediol is a useful reagent for the surface modification (hydrophobization) of oxidized silicon and other oxidized metal surfaces and compare the wetting properties of modified solids with those of conventionally modified surfaces. That water is the only byproduct of this modification reaction suggests that this and likely other silanediols are useful surface-modification agents, particularly when substrate corrosion or the competitive adsorption of byproducts is an issue. We note that dimethylsilanediol is volatile with a significant vapor pressure at room temperature. Vapor-phase surface modifications are also reported.

Surface-engineered gold nanorods: promising DNA vaccine adjuvant for HIV-1 treatment.

With the intense international response to the AIDS pandemic, HIV vaccines have been extensively investigated but have failed due to issues of safety or efficacy in humans. Adjuvants for HIV/AIDS vaccines are under intense research but a rational design approach is still lacking. Nanomaterials represent an obvious opportunity in this field due to their unique physicochemical properties. Gold nanostructures are being actively studied as a promising and versatile platform for biomedical application. Herein, we report novel surface-engineered gold nanorods (NRs) used as promising DNA vaccine adjuvant for HIV treatment. We have exploited the effects of surface chemistry on the adjuvant activity of the gold nanorod by placing three kinds of molecules, that is, cetyltrimethylammonium bromide (CTAB), poly(diallydimethylammonium chloride) (PDDAC), and polyethyleneimine (PEI) on the surface of the nanorod. These PDDAC- or PEI-modified Au NRs can significantly promote cellular and humoral immunity as well as T cell proliferation through activating antigen-presenting cells if compared to naked HIV-1 Env plasmid DNA treatment in vivo. These findings have shed light on the rational design of low-toxic nanomaterials as a versatile platform for vaccine nanoadjuvants/delivery systems.

A liposome-based aptasensor integrated with competitive reaction enabling portable and electrochemical detection of Aß oligomer.

Aggregation of ß-amyloid (Aß) were considered as a typical pathological feature of Alzheimer's disease (AD). Extensive studies have verified that soluble Aß oligomers (AßO) were more toxic to neurons than plaques. Herein, in this work, a glucose entrapped liposome-based portable aptasensor was fabricated for recognizing and interacting with AßO by specific aptamer on liposome (G-Lip-Apt). Then, a single strand DNA, designed to be partially complementary to AßO aptamer, was modified on amino-functionalized Fe3O4@SiO2 to obtain a magnetic nanocomposite (Fe3O4@SiO2/NH2-DNA). In the presence of AßO, the specific recognition between AßO and its aptamer on G-Lip-Apt made AßO bounded with G-Lip-Apt. With subsequent introduction of Fe3O4@SiO2/NH2-DNA, the unreacted G-Lip-Apt was further linked with Fe3O4@SiO2/NH2-DNA by double stranded complementary pairing interaction. Along with the addition of TritonX-100 into the formed G-Lip-Apt/Fe3O4@SiO2/NH2-DNA complex, the encapsulated glucose was released from liposome and then measured by a personal glucose meter (PGM). Good linear correlation was acquired over concentration of 5.0-1000 nM and the limit of detection (LOD) was calculated to be 2.27 nM for AßO. The developed portable electrochemical strategy integrated magnetic separation, competitive reaction and point of care test (POCT) to achieve high sensitivity, selectivity and accuracy, therefore enabled it successfully applied to the analysis of AßO in the hippocampus and cortex of APP/PS1 transgenic AD mice.

Surface-Modified Nano-Hydroxyapatite Uniformly Dispersed on High-Porous GelMA Scaffold Surfaces for Enhanced Osteochondral Regeneration.

Purpose: This study aims to investigate the impact of enhancing subchondral bone repair on the efficacy of articular cartilage restoration, thereby achieving improved osteochondral regeneration outcomes. Methods: In this study, we modified the surface of nano-hydroxyapatite (n-HAp) through alkylation reactions to prepare n-HApMA. Characterization techniques, including X-ray diffraction, infrared spectroscopy scanning, thermogravimetric analysis, particle size analysis, and electron microscopy, were employed to analyze n-HApMA. Bioinks were prepared using n-HApMA, high porosity GelMA hydrogel, and adipose tissue derived stromal cells (ADSCs). The rheological properties of the bioinks during photocuring were investigated using a rheometer. Based on these bioinks, a biphasic scaffold was constructed. The viability of cells within the scaffold was observed using live-dead cell staining, while the internal morphology was examined using scanning electron microscopy. The stiffness of the scaffold was evaluated through compression testing. Scaffolds were implanted into the osteochondral defects of New Zealand rabbit knees, and microCT was utilized to observe the subchondral bone repair. Hematoxylin and eosin (H&E) staining, Masson's trichrome staining, and Safranin O/Fast Green staining were performed to assess the regeneration of subchondral bone and cartilage. Furthermore, immunohistochemical staining was employed to detect the expression of osteogenic and chondrogenic-related molecules. Results: Scaffold characterization revealed that surface modification enables the uniform distribution of n-HApMA within the GelMA matrix. The incorporation of 5% n-HApMA notably enhanced the elastic modulus and stiffness of the 6% high-porosity GelMA in comparison to n-HAp. Moreover, in-vivo study showed that the homogeneous dispersion of n-HApMA on the GelMA matrix facilitated the osteogenic differentiation of adipose-derived stem cells (ADSCs) and promoted osteochondral tissue regeneration. Conclusion: These findings suggest potential applications of the n-HApMA/GelMA composite in the field of tissue engineering and regenerative medicine.