Efficient Assessment of Tumor Vascular Shutdown by Photodynamic Therapy on Orthotopic Pancreatic Cancer Using High-Speed Wide-Field Waterproof Galvanometer Scanner Photoacoustic Microscopy.

To identify the vascular alteration by photodynamic therapy (PDT), the utilization of high-resolution, high-speed, and wide-field photoacoustic microscopy (PAM) has gained enormous interest. The rapid changes in vasculature during PDT treatment and monitoring of tumor tissue activation in the orthotopic pancreatic cancer model have received limited attention in previous studies. Here, a fully two-axes waterproof galvanometer scanner-based photoacoustic microscopy (WGS-PAM) system was developed for in vivo monitoring of dynamic variations in micro blood vessels due to PDT in an orthotopic pancreatic cancer mouse model. The photosensitizer (PS), Chlorin e6 (Ce6), was utilized to activate antitumor reactions in response to the irradiation of a 660 nm light source. Microvasculatures of angiogenesis tissue were visualized on a 40 mm2 area using the WGS-PAM system at 30 min intervals for 3 h after the PDT treatment. The decline in vascular intensity was observed at 24.5% along with a 32.4% reduction of the vascular density at 3 h post-PDT by the analysis of PAM images. The anti-vascularization effect was also identified with fluorescent imaging. Moreover, Ce6-PDT increased apoptotic and necrotic markers while decreasing vascular endothelial growth factor (VEGF) expression in MIA PaCa-2 and BxPC-3 pancreatic cancer cell lines. The approach of the WGS-PAM system shows the potential to investigate PDT effects on the mechanism of angiographic dynamics with high-resolution wide-field imaging modalities.

Extrusion 3D-printing and characterization of poly(caprolactone fumarate) for bone regeneration applications.

Polycaprolactone fumarate (PCLF) is a cross-linkable PCL derivative extensively considered for tissue engineering applications. Although injection molding has been widely used to develop PCLF scaffolds, platforms developed using such technique lack precise control on architecture, design, and porosity required to ensure adequate cellular and tissue responses. In particular, the scaffolds should provide a suitable surface for cell attachment and proliferation, and facilitate cell-cell communication and nutrient flow. 3D printing technologies have led to new architype for biomaterial development with micro-architecture mimicking native tissue. Here, we developed a method for 3D printing of PCLF structures using the extrusion printing technique. The crosslinking property of PCLF enabled the unique post-processing of 3D printed scaffolds resulting in highly porous and flexible PCLF scaffolds with compressive properties imitating natural features of cancellous bone. Generated scaffolds supported excellent attachment and proliferation of mesenchymal stem cells (MSC). The high porosity of PCLF scaffolds facilitated vascularized membrane formation demonstrable with the stringency of the ex ovo chicken chorioallantoic membrane (CAM) implantation. Furthermore, upon implantation to rat calvarium defects, PCLF scaffolds enabled an exceptional new bone formation with a bone mineral density of newly formed bone mirroring native bone tissue. These studies suggest that the 3D-printed highly porous PCLF scaffolds may serve as a suitable biomaterial platform to significantly expand the utility of the PCLF biomaterial for bone tissue engineering applications.

3D-printed scaffolds with 2D hetero-nanostructures and immunomodulatory cytokines provide pro-healing microenvironment for enhanced bone regeneration.

Three-dimensional (3D) printing technology is driving forward the progresses of various engineering fields, including tissue engineering. However, the pristine 3D-printed scaffolds usually lack robust functions in stimulating desired activity for varied regeneration applications. In this study, we combined the two-dimensional (2D) hetero-nanostructures and immuno-regulative interleukin-4 (IL-4) cytokines for the functionalization of 3D-printed scaffolds to achieve a pro-healing immuno-microenvironment for optimized bone injury repair. The 2D hetero-nanostructure consists of graphene oxide (GO) layers, for improved cell adhesion, and black phosphorous (BP) nanosheets, for the continuous release of phosphate ions to stimulate cell growth and osteogenesis. In addition, the 2D hetero-nanolayers facilitated the adsorption of large content of immuno-regulative IL-4 cytokines, which modulated the polarization of macrophages into M2 phenotype. After in vivo implantation in rat, the immuno-functioned 3D-scaffolds achieved in vivo osteo-immunomodulation by building a pro-healing immunological microenvironment for better angiogenesis and osteogenesis in the defect area and thus facilitated bone regeneration. These results demonstrated that the immuno-functionalization of 3D-scaffolds with 2D hetero-nanostructures with secondary loading of immuno-regulative cytokines is an encouraging strategy for improving bone regeneration.

Exosome biopotentiated hydrogel restores damaged skeletal muscle in a porcine model of stress urinary incontinence.

Urinary incontinence afflicts up to 40% of adult women in the United States. Stress urinary incontinence (SUI) accounts for approximately one-third of these cases, precipitating ~200,000 surgical procedures annually. Continence is maintained through the interplay of sub-urethral support and urethral sphincter coaptation, particularly during activities that increase intra-abdominal pressure. Currently, surgical correction of SUI focuses on the re-establishment of sub-urethral support. However, mesh-based repairs are associated with foreign body reactions and poor localized tissue healing, which leads to mesh exposure, prompting the pursuit of technologies that restore external urethral sphincter function and limit surgical risk. The present work utilizes a human platelet-derived CD41a and CD9 expressing extracellular vesicle product (PEP) enriched for NF-κB and PD-L1 and derived to ensure the preservation of lipid bilayer for enhanced stability and compatibility with hydrogel-based sustained delivery approaches. In vitro, the application of PEP to skeletal muscle satellite cells in vitro drove proliferation and differentiation in an NF-κB-dependent fashion, with full inhibition of impact on exposure to resveratrol. PEP biopotentiation of collagen-1 and fibrin glue hydrogel achieved sustained exosome release at 37 °C, creating an ultrastructural "bead on a string" pattern on scanning electron microscopy. Initial testing in a rodent model of latissimus dorsi injury documented activation of skeletal muscle proliferation of healing. In a porcine model of stress urinary incontinence, delivery of PEP-biopotentiated collagen-1 induced functional restoration of the external urethral sphincter. The histological evaluation found that sustained PEP release was associated with new skeletal muscle formation and polarization of local macrophages towards the regenerative M2 phenotype. The results provided herein serve as the first description of PEP-based biopotentiation of hydrogels implemented to restore skeletal muscle function and may serve as a promising approach for the nonsurgical management of SUI.

Target ischemic stroke model creation method using photoacoustic microscopy with simultaneous vessel monitoring and dynamic photothrombosis induction.

The ischemic stroke animal model evaluates the efficacy of reperfusion and neuroprotective strategies for ischemic injuries. Various conventional methods have been reported to induce the ischemic models; however, controlling specific neurological deficits, mortality rates, and the extent of the infarction is difficult as the size of the affected region is not precisely controlled. In this paper, we report a single laser-based localized target ischemic stroke model development method by simultaneous vessel monitoring and photothrombosis induction using photoacoustic microscopy (PAM), which has minimized the infarct size at precise location with high reproducibility. The proposed method has significantly reduced the infarcted region by illuminating the precise localization. The reproducibility and validity of suggested method have been demonstrated through repeated experiments and histological analyses. These results demonstrate that our method can provide the ischemic stroke model closest to the clinical pathology for brain ischemia research from inducement, occurrence mechanisms to the recovery process.

KATP channel dependent heart multiome atlas.

Plasmalemmal ATP sensitive potassium (KATP) channels are recognized metabolic sensors, yet their cellular reach is less well understood. Here, transgenic Kir6.2 null hearts devoid of the KATP channel pore underwent multiomics surveillance and systems interrogation versus wildtype counterparts. Despite maintained organ performance, the knockout proteome deviated beyond a discrete loss of constitutive KATP channel subunits. Multidimensional nano-flow liquid chromatography tandem mass spectrometry resolved 111 differentially expressed proteins and their expanded network neighborhood, dominated by metabolic process engagement. Independent multimodal chemometric gas and liquid chromatography mass spectrometry unveiled differential expression of over one quarter of measured metabolites discriminating the Kir6.2 deficient heart metabolome. Supervised class analogy ranking and unsupervised enrichment analysis prioritized nicotinamide adenine dinucleotide (NAD+), affirmed by extensive overrepresentation of NAD+ associated circuitry. The remodeled metabolome and proteome revealed functional convergence and an integrated signature of disease susceptibility. Deciphered cardiac patterns were traceable in the corresponding plasma metabolome, with tissue concordant plasma changes offering surrogate metabolite markers of myocardial latent vulnerability. Thus, Kir6.2 deficit precipitates multiome reorganization, mapping a comprehensive atlas of the KATP channel dependent landscape.

Size-dependent osteogenesis of black phosphorus in nanocomposite hydrogel scaffolds.

A promising new strategy emerged in bone tissue engineering is to incorporate black phosphorus (BP) into polymer scaffolds, fabricating nanocomposite hydrogel platforms with biocompatibility, degradation controllability, and osteogenic capacity. BP quantum dot is a new concept and stands out recently among the BP family due to its tiny structure and a series of excellent characteristics. In this study, BP was processed into nanosheets of three different sizes via different exfoliation strategies and then incorporated into cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) to produce nanocomposite hydrogels for bone regeneration. The three different BP nanosheets were designated as BP-L, BP-M, and BP-S, with a corresponding diameter of 242.3 ± 90.0, 107.1 ± 47.9, and 18.8 ± 4.6 nm. The degradation kinetics and osteogenic capacity of MC3T3 pre-osteoblasts in vitro were both dependent on the BP size. BP exhibited a controllable degradation rate, which increased with the decrease of the size of the nanosheets, coupled with the release of phosphate in vitro. The osteogenic capacity of the hydrogels was promoted with the addition of all BP nanosheets, compared with OPF hydrogel alone. The smallest BP quantum dots was shown to be optimal in enhancing MC3T3 cell behaviors, including spreading, distribution, proliferation, and differentiation on the OPF hydrogels. These results reinforced that the supplementation of BP quantum dots into OPF nanocomposite hydrogel scaffolds could potentially find application in the restoration of bone defects.

Scaffold-Free Spheroids with Two-Dimensional Heteronano-Layers (2DHNL) Enabling Stem Cell and Osteogenic Factor Codelivery for Bone Repair.

Scaffold-free spheroids offer great potential as a direct supply of cells for bottom-up bone tissue engineering. However, the building of functional spheroids with both cells and bioactive signals remains challenging. Here, we engineered functional spheroids with mesenchymal stem cells (MSCs) and two-dimensional heteronano-layers (2DHNL) that consisted of black phosphorus (BP) and graphene oxide (GO) to create a 3D cell-instructive microenvironment for large defect bone repair. The effects of the engineered 2D materials on the proliferation, osteogenic differentiation of stem cells was evaluated in an in vitro 3D spheroidal microenvironment. Excellent in vivo support of osteogenesis of MSCs, neovascularization, and bone regeneration was achieved after transplanting these engineered spheroids into critical-sized rat calvarial defects. Further loading of osteogenic factor dexamethasone (DEX) on the 2DHNL showed outstanding in vivo osteogenic induction and bone regrowth without prior in vitro culture in osteogenic medium. The shortened overall culture time would be advantageous for clinical translation. These functional spheroids impregnated with engineered 2DHNL enabling stem cell and osteogenic factor codelivery could be promising functional building blocks to provide cells and differential clues in an all-in-one system to create large tissues for time-effective in vivo bone repair.

SDF-1α/OPF/BP Composites Enhance the Migrating and Osteogenic Abilities of Mesenchymal Stem Cells.

In situ cell recruitment is a promising regenerative medicine strategy with the purpose of tissue regeneration without stem cell transplantation. This chemotaxis-based strategy is aimed at ensuring a restorative environment through the release of chemokines that promote site-specific migration of healing cell populations. Stromal cell-derived factor-1α (SDF-1α) is a critical chemokine that can regulate the migration of mesenchymal stem cells (MSCs). Accordingly, here, SDF-1α-loaded microporous oligo[poly(ethylene glycol) fumarate]/bis[2-(methacryloyloxy)ethyl] phosphate composites (SDF-1α/OPF/BP) were engineered and probed. SDF-1α/OPF/BP composites were loaded with escalating SDF-1α concentrations, namely, 0 ng/ml, 50 ng/ml, 100 ng/ml, and 200 ng/ml, and were cocultured with MSC. Scratching assay, Transwell assay, and three-dimensional migration model were utilized to assess the migration response of MSCs. Immunofluorescence staining of Runx2 and osteopontin (OPN), ELISA assay of osteocalcin (OCN) and alkaline phosphatase (ALP), and Alizarin Red S staining were conducted to assess the osteogenesis of MSCs. All SDF-1α/OPF/BP composites engendered a release of SDF-1α (>80%) during the first four days. SDF-1α released from the composites significantly promoted migration and osteogenic differentiation of MSCs documented by upregulated expression of osteogenic-related proteins, ALP, Runx2, OCN, and OPN. SDF-1α at 100 ng/ml was optimal for enhanced migration and osteogenic proficiency. Thus, designed SDF-1α/OPF/BP composites were competent in promoting the homing and osteogenesis of MSCs and thus offer a promising bioactive scaffold candidate for on-demand bone tissue regeneration.

Endoscopy within 7 days after detecting high calprotectin levels can be useful for therapeutic decision-making in ulcerative colitis.

ABSTRACT: The aim of this study was to assess the appropriate time interval to identify the association between the fecal calprotectin (FC) test and endoscopic activity, and to evaluate whether the time interval affects the therapeutic plan adjustment in patients with ulcerative colitis (UC).This study included 103 patients who underwent FC tests and endoscopic examinations within the past three months. The FC test results classified cases into three groups as follows: moderate to severe (>200, >250, or >300 µg/g), mild (100-200, 100-250, or 100-300 µg/g), and inactive (<100 µg/g) activity. The Mayo endoscopic subscore was used to determine endoscopic activity. Therapeutic plan adjustment included the addition or increased dosage of anti-inflammatory drugs, steroids, immunomodulators, and biologics.Using the cutoff value for FC of 200 µg/g, the appropriate time interval for dividing the association and non-association between Mayo endoscopic subscore and FC was 7 days (sensitivity, 74.4%; specificity, 50.0%; area under the curve [AUC], 0.6032). When using FC 250 or 300 µg/g, the appropriate time interval was 5.5 days, with a sensitivity of 71.7% and specificity of 49.1 (AUC 0.5862) in FC 250 µg/g, a sensitivity of 69.6%, and a specificity of 47.4 (AUC 0.5549) for FC 300 µg/g. Therapeutic plans changed in 29.1% of patients. In patients with shorter intervals (≤7 days) between the FC test and endoscopy, significant therapeutic plan adjustments were observed in patients with UC (36.5% vs. 17.5%, P = .047).Although the need for endoscopy within 7 days after detecting high FC (≥ 200 µg/g) was not statistically supported, endoscopy within a shorter interval (≤7 days) in UC patients with high FC can help determine the therapeutic plan.

Injectable catalyst-free "click" organic-inorganic nanohybrid (click-ON) cement for minimally invasive in vivo bone repair.

Injectable polymers have attracted intensive attention in tissue engineering and drug delivery applications. Current injectable polymer systems often require free-radical or heavy-metal initiators and catalysts for the crosslinking process, which may be extremely toxic to the human body. Here, we report a novel polyhedral oligomeric silsesquioxane (POSS) based strain-promoted alkyne-azide cycloaddition (SPAAC) "click" organic-inorganic nanohybrids (click-ON) system that can be click-crosslinked without any toxic initiators or catalysts. The click-ON scaffolds supported excellent adhesion, proliferation, and osteogenesis of stem cells. In vivo evaluation using a rat cranial defect model showed outstanding bone formation with minimum cytotoxicity. Essential osteogenic alkaline phosphatase (ALP) and vascular CD31 marker expression were detected on the defect site, indicating excellent support of in vivo osteogenesis and vascularization. Using salt leaching techniques, an injectable porous click-ON cement was developed to create porous structures and support better in vivo bone regeneration. Beyond defect filling, the click-ON cement also showed promising application for spinal fusion using rabbits as a model. Compared to the current clinically used poly (methyl methacrylate) (PMMA) cement, this click-ON cement showed great advantages of low heat generation, better biocompatibility and biodegradability, and thus has great potential for bone and related tissue engineering applications.

Secretome signature of cardiopoietic cells echoed in rescued infarcted heart proteome.

Stem cell paracrine activity is implicated in cardiac repair. Linkage between secretome functionality and therapeutic outcome was here interrogated by systems analytics of biobanked human cardiopoietic cells, a regenerative biologic in advanced clinical trials. Protein chip array identified 155 proteins differentially secreted by cardiopoietic cells with clinical benefit, expanded into a 520 node network, collectively revealing inherent vasculogenic properties along with cardiac and smooth muscle differentiation and development. Next generation RNA sequencing, refined by pathway analysis, pinpointed miR-146 dependent regulation upstream of the decoded secretome. Intracellular and extracellular integration unmasked commonality across cardio-vasculogenic processes. Mirroring the secretome pattern, infarcted hearts benefiting from cardiopoietic cell therapy restored the disease proteome engaging cardiovascular system functions. The cardiopoietic cell secretome thus confers a therapeutic molecular imprint on recipient hearts, with response informed by predictive systems profiling.

Role of α2-Adrenoceptor Subtypes in Suppression of L-Type Ca2+ Current in Mouse Cardiac Myocytes.

Sarcolemmal α2 adrenoceptors (α2-AR), represented by α2A, α2B and α2C isoforms, can safeguard cardiac muscle under sympathoadrenergic surge by governing Ca2+ handling and contractility of cardiomyocytes. Cardiomyocyte-specific targeting of α2-AR would provide cardiac muscle-delimited stress control and enhance the efficacy of cardiac malfunction treatments. However, little is known about the specific contribution of the α2-AR subtypes in modulating cardiomyocyte functions. Herein, we analyzed the expression profile of α2A, α2B and α2C subtypes in mouse ventricle and conducted electrophysiological antagonist assay evaluating the contribution of these isoforms to the suppression of L-type Ca2+ current (ICaL). Patch-clamp electro-pharmacological studies revealed that the α2-agonist-induced suppression of ICaL involves mainly the α2C, to a lesser extent the α2B, and not the α2A isoforms. RT-qPCR evaluation revealed the presence of adra2b and adra2c (α2B and α2C isoform genes, respectively), but was unable to identify the expression of adra2a (α2A isoform gene) in the mouse left ventricle. Immunoblotting confirmed the presence only of the α2B and the α2C proteins in this tissue. The identified α2-AR isoform-linked regulation of ICaL in the mouse ventricle provides an important molecular substrate for the cardioprotective targeting.

Black phosphorus incorporation modulates nanocomposite hydrogel properties and subsequent MC3T3 cell attachment, proliferation, and differentiation.

A promising strategy that emerged in tissue engineering is to incorporate two-dimensional (2D) materials into polymer scaffolds, producing materials with desirable mechanical properties and surface chemistries, which also display broad biocompatibility. Black phosphorus (BP) is a 2D material that has sparked recent scientific interest due to its unique structure and electrochemical characteristics. In this study, BP nanosheets (BPNSs) were incorporated into a cross-linkable oligo[poly(ethylene glycol) fumarate] (OPF) hydrogel to produce a new nanocomposite for bone regeneration. BPNSs exhibited a controllable degradation rate coupled with the release of phosphate in vitro. MTS assay results together with live/dead images confirmed that the introduction of BPNSs into OPF hydrogels enhanced MC3T3-E1 cell proliferation. Moreover, the morphology parameters indicated better attachments of cells in the BPNSs containing group. Immunofluorescence images as well as intercellular ALP and OCN activities showed that adding a certain amount of BPNSs to OPF hydrogel could greatly improve differentiation of pre-osteoblasts on the hydrogel. Additionally, embedding black phosphorous into a neutral polymer network helped to control its cytotoxicity, with optimal cell growth observed at BP concentrations as high as 500 ppm. These results reinforced that the supplementation of OPF with BPNSs can increase the osteogenic capacity of polymer scaffolds for use in bone tissue engineering.

Adenylate kinase AK2 isoform integral in embryo and adult heart homeostasis.

Adenylate kinase2 (AK2) catalyzes trans-compartmental nucleotide exchange, but the functional implications of this mitochondrial intermembrane isoform is only partially understood. Here, transgenic AK2-/- null homozygosity was lethal early in embryo, indicating a mandatory role for intact AK2 in utero development. In the adult, conditional organ-specific ablation of AK2 precipitated abrupt heart failure with Krebs cycle and glycolytic metabolite buildup, suggesting a vital contribution to energy demanding cardiac performance. Depressed pump function recovered to pre-deletion levels overtime, suggestive of an adaptive response. Compensatory upregulation of phosphotransferase AK1, AK3, AK4 isozymes, creatine kinase isoforms, and hexokinase, along with remodeling of cell cycle/growth genes and mitochondrial ultrastructure supported organ rescue. Taken together, the requirement of AK2 in early embryonic stages, and the immediate collapse of heart performance in the AK2-deficient postnatal state underscore a primordial function of the AK2 isoform. Unsalvageable in embryo, loss of AK2 in the adult heart was recoverable, underscoring an AK2-integrated bioenergetics system with innate plasticity to maintain homeostasis on demand.

Enhanced nerve cell proliferation and differentiation on electrically conductive scaffolds embedded with graphene and carbon nanotubes.

Conduits that promote nerve regeneration are currently of great medical concern, particularly when gaps exist between nerve endings. To address this issue, our laboratory previously developed a nerve conduit from biodegradable poly(caprolactone fumarate) (PCLF) that supports peripheral nerve regeneration. The present study improves upon this work by further developing an electrically conductive, positively charged PCLF scaffold through the incorporation of graphene, carbon nanotubes (CNTs), and [2-(methacryloyloxy)ethyl]trimethylammonium chloride (MTAC) (PCLF-Graphene-CNT-MTAC) using ultraviolet (UV) induced photocrosslinking. Scanning electron microscopy, transmission electron microscopy, and atomic force microscopy were used to assess the incorporation of CNTs and graphene into PCLF-Graphene-CNT-MTAC scaffolds, which displayed enhanced surface roughness and reduced electrochemical impedance when compared to neat PCLF. Scaffolds with these surface modifications also showed improved growth and differentiation of rat pheochromocytoma 12 cells in vitro, with enhanced cell growth, neurite extension, and cellular migration. Furthermore, an increased number of neurite protrusions were observed when the conduit was electrically stimulated. These results show that the electrically conductive PCLF-Graphene-CNT-MTAC nerve scaffolds presented here support the cellular behaviors that are critical for nerve regeneration, ultimately making this material an attractive candidate for regenerative medicine applications.

Electrochemical detection of white spot syndrome virus with a silicone rubber disposable electrode composed of graphene quantum dots and gold nanoparticle-embedded polyaniline nanowires.

BACKGROUND: With the enormous increment of globalization and global warming, it is expected that the number of newly evolved infectious diseases will continue to increase. To prevent damage due to these infections, the development of a diagnostic method for detecting a virus with high sensitivity in a short time is highly desired. In this study, we have developed a disposable electrode with high-sensitivity and accuracy to evaluate its performances for several target viruses. RESULTS: Conductive silicon rubber (CSR) was used to fabricate a disposable sensing matrix composed of nitrogen and sulfur-co-doped graphene quantum dots (N,S-GQDs) and a gold-polyaniline nanocomposite (AuNP-PAni). A specific anti-white spot syndrome virus (WSSV) antibody was conjugated to the surface of this nanocomposite, which was successfully applied for the detection of WSSV over a wide linear range of concentration from 1.45 × 102 to 1.45 × 105 DNA copies/ml, with a detection limit as low as 48.4 DNA copies/ml. CONCLUSION: The engineered sensor electrode can retain the detection activity up to 5 weeks, to confirm its long-term stability, required for disposable sensing applications. This is the first demonstration of the detection of WSSV by a nanofabricated sensing electrode with high sensitivity, selectivity, and stability, providing as a potential diagnostic tool to monitor WSSV in the aquaculture industry.

Controlling distance, size and concentration of nanoconjugates for optimized LSPR based biosensors.

In this report, we have examined the distance- and size-dependent localized surface plasmon resonance (LSPR) between fluorescent quantum dots (QDs) and adjacent gold nanoparticles (AuNPs) to provide a comprehensive evaluation, aiming for practical application in biosensing platform. A series of peptides with different chain lengths, connected between QDs and AuNPs is initially applied to prepare various CdSe QDs-peptide-AuNP systems to optimize LSPR signal. Separation distance between two nanoparticles of these systems before and after conjugation is also confirmed by quantum mechanical modeling and corroborated with their LSPR influenced fluorescence variations. After detailed optimizations, it can be noted that larger sized AuNPs make strong quenching of QDs, which gradually shows enhancement of fluorescence with the increment of distance and the smaller sized AuNPs. Depending on the requirement, it is possible to tune the optimized structure of the CdSe QD-peptide-AuNP nanostructures for the application. In this work, two different structural designs with different peptide chain length are chosen to construct two biosensor systems, observing their fluorescence enhancement and quenching effects, respectively. Using different structural orientation of these biosensors, two nanoconjugates has applied for detection of norovirus and influenza virus, respectively to confirm their application in sensing.

3D-printed scaffolds with carbon nanotubes for bone tissue engineering: Fast and homogeneous one-step functionalization.

Three-dimensional (3D) printing is a promising technology for tissue engineering. However, 3D-printing methods are limited in their ability to produce desired microscale features or electrochemical properties in support of robust cell adhesion, proliferation, and differentiation. This study addresses this deficiency by proposing an integrated, one-step, method to increase the cytocompatibility of 3D-printed scaffolds through functionalization leveraging conductive carbon nanotubes (CNTs). To this end, CNTs were first sonicated with water-soluble single-stranded deoxyribonucleic acid (ssDNA) to generate a negatively charged ssDNA@CNT nano-complex. Concomitantly, 3D-printed poly(propylene fumarate) (PPF) scaffolds were ammonolyzed to introduce free amine groups, which can take on a positive surface charge in water. The ssDNA@CNT nano-complex was then applied to 3D-printed scaffolds through a simple one-step coating utilizing electric-static force. This fast and facile functionalization step resulted in a homogenous and non-toxic coating of CNTs to the surface, which significantly improved the adhesion, proliferation, and differentiation of pre-osteoblast cells. In addition, the CNT based conductive coating layer enabled modulation of cell behavior through electrical stimuli (ES) leading to cellular proliferation and osteogenic gene marker expression, including alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Collectively, these data provide the foundation for a one-step functionalization method for simple, fast, and effective functionalization of 3D printed scaffolds that support enhanced cell adhesion, proliferation, and differentiation, especially when employed in conjunction with ES. STATEMENT OF SIGNIFICANCE: Three-dimensional (3D) printing is a promising technology for tissue engineering. However, 3D-printing methods have limited ability to produce desired features or electrochemical properties in support of robust cell behavior. To address this deficiency, the current study proposed an integrated, one-step method to increase the cytocompatibility of 3D-printed scaffolds through functionalization leveraging conductive carbon nanotubes (CNTs). This fast and facile functionalization resulted in a homogenous and non-toxic coating of CNTs to the surface, which significantly improved the adhesion, proliferation, and differentiation of cells on the 3D-printed scaffolds.