Role of a2b1 integrins in mediating cell shape on microtextured titanium surfaces

Surface microroughness plays an important role in determining osteoblast behavior on titanium. Previous studies have shown that osteoblast differentiation on microtextured titanium substrates is dependent on alpha-2 beta-1 (a2b1) integrin signaling. This study used focused ion beam milling and scanning electron microscopy, combined with three-dimensional image reconstruction, to investigate early interactions of individual cells with their substrate and the role of integrin a2b1 in determining cell shape. MG63 osteoblast-like cells on sand blasted/acid etched (SLA) Ti surfaces after 3 days of culturing indicated decreased cell number, increased cell differentiation, and increased expression of mRNA levels for a1, a2, aV, and b1 integrin subunits compared to cells on smooth Ti (PT) surfaces. a2 or b1 silenced cells exhibited increased cell number and decreased differentiation on SLA compared to wild-type cells. Wild-type cells on SLA possessed an elongated morphology with reduced cell area, increased cell thickness, and more apparent contact points. Cells on PT exhibited greater spreading and were relatively flat. Silenced cells possessed a morphology and phenotype similar to wild-type cells grown on PT. These observations indicate that surface microroughness affects cell response via a2b1 integrin signaling, resulting in a cell shape that promotes osteoblastic differentiation. VC 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 564–573, 2015.Surface microroughness plays an important role in determining osteoblast behavior on titanium. Previous studies have shown that osteoblast differentiation on microtextured titanium substrates is dependent on alpha-2 beta-1 (a2b1) integrin signaling. This study used focused ion beam milling and scanning electron microscopy, combined with three-dimensional image reconstruction, to investigate early interactions of individual cells with their substrate and the role of integrin a2b1 in determining cell shape. MG63 osteoblast-like cells on sand blasted/acid etched (SLA) Ti surfaces after 3 days of culturing indicated decreased cell number, increased cell differentiation, and increased expression of mRNA levels for a1, a2, aV, and b1 integrin subunits compared to cells on smooth Ti (PT) surfaces. a2 or b1 silenced cells exhibited increased cell number and decreased differentiation on SLA compared to wild-type cells. Wild-type cells on SLA possessed an elongated morphology with reduced cell area, increased cell thickness, and more apparent contact points. Cells on PT exhibited greater spreading and were relatively flat. Silenced cells possessed a morphology and phenotype similar to wild-type cells grown on PT. These observations indicate that surface microroughness affects cell response via a2b1 integrin signaling, resulting in a cell shape that promotes osteoblastic differentiation. VC 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 564–573, 2015

Mulberry leaf lipid nanoparticles: a naturally targeted CRISPR/Cas9 oral delivery platform for alleviation of colon diseases

Oral treatment of colon diseases with the CRISPR/Cas9 system has been hampered by the lack of a safe and efficient delivery platform. Overexpressed CD98 plays a crucial role in the progression of ulcerative colitis (UC) and colitis-associated colorectal cancer (CAC). In this study, lipid nanoparticles (LNPs) derived from mulberry leaves are functionalized with Pluronic copolymers and optimized to deliver the CRISPR/Cas gene editing machinery for CD98 knockdown. The obtained LNPs possessed a hydrodynamic diameter of 267.2 nm, a narrow size distribution, and a negative surface charge (â 25.6 mV). Incorporating Pluronic F127 into LNPs improved their stability in the gastrointestinal tract and facilitated their penetration through the colonic mucus barrier. The galactose end groups promoted endocytosis of the LNPs by macrophages via asialoglycoprotein receptor-mediated endocytosis, with a transfection efficiency of 2.2-fold higher than Lipofectamine 6000. The LNPs significantly decreased CD98 expression, down-regulated pro-inflammatory cytokines (TNF-α and IL-6), up-regulated anti-inflammatory factors (IL-10), and polarized macrophages to M2 phenotype. Oral administration of LNPs mitigated UC and CAC by alleviating inflammation, restoring the colonic barrier, and modulating intestinal microbiota. As the first oral CRISPR/Cas9 delivery LNP, this system offers a precise and efficient platform for the oral treatment of colon diseases.This study was supported by the National Natural Science Foundation of China (82072060, 82360110, and 22008201), the Science and Technology Department of Jiangxi Province (20212BDH81019 and 20224BAB206073), the Fundamental Research Funds for the Central Universities (SWU-XDPY22006 and SWU-KQ22075), the Venture & Innovation Support Pro-gram for Chongqing Overseas Returnees (2205012980212766), and theScience Fund for Distinguished Young Scholars of Chongqing Municipality (2022NSCQ-JQX5279)

Tumor-targeted upconverting nanoplatform constructed by host-guest interaction for near-infrared-light-actuated synergistic photodynamic-/chemotherapy

The strategic combination of photodynamic therapy and chemotherapy has emerged as a promising treatment option for various tumor indications, which not only expands our understanding of each individual modality but also reveals new opportunities to achieve superadditive benefit via exploring their internal synergy rather than simple mixing. In this study, dual-emissive upconverting nanoparticle (UCNP) was employed to bridge the two treatment regimens to synergistically reinforce the therapeutic efficacy. The UCNP-based drug delivery nanoplatform was first co-loaded with 1,8-dihydroxy-3-methylanthraquinone (DHMA) photosensitizers and UV-activatable camptothecin prodrug (NBCCPT) and then complexed with biofunctional β-cyclodextrin species (β-CD-PEG-LA) via highly specific host-guest interactions to cap the camptothecin prodrug conjugated on the nanoparticle surface. The supramolecularly attached β-CD-PEG-LA could not only enhance the aqueous dispersity of the nanocarriers and prevent DHMA leakage, but also imbues targeting effect against asialoglycoprotein receptor-overexpressing tumor cells. The UCNP core would convert the NIR excitation (980 nm) into localized UV (360 nm) and visible (480 nm) emissions, of which the former would cleave the nitrobenzene linker to restore the cytotoxicity of CPT while the latter could excite the photosensitizer to generate reactive oxygen species (ROS). In addition to the photodynamic damage, the light-generated ROS could also facilitate the endo/lysosomal escape of the endocytosed nanoparticles and improve the overall antitumor potency in a synergistic manner.Agency for Science, Technology and Research (A*STAR)National Research Foundation (NRF)This research is supported by the National Natural Science Foundation of China (11832008, 51773023, 51602034, 51603024, 51825302, 21734002), National Key R&D Program of China (2016YFC1100300, 2017YFB0702603), Innovation Project on Industrial Generic Key Technologies of Chongqing (cstc2015zdcy-ztzx120003), Natural Science Foundation of Chongqing Municipal Government (cstc2018jcyjAX0368), People's Livelihood Special Innovation Projects of Chongqing CSTC (cstc2017shmsA130071), Fundamental Research Funds for the Central Universities (2018CDQYSM0036), Innovation Team in University of Chongqing Municipal Government (CXTDX201601002), Singapore Agency for Science, Technology and Research (A*STAR) AME IRG grant (A1883c0005) and the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03)

Engineered drug delivery nanosystems for tumor microenvironment normalization therapy

As a complex “soil” ecosystem, the tumor microenvironment (TME) plays a crucial role in the occurrence, development and metastasis of tumors. Reprogramming TME can block the interactive network between tumors and extracellular matrix (ECM) / various surrounding cells and contribute to tumor effective damage, which is a potential therapeutic target in oncotherapy. Nanobiomaterials have received more attention due to their excellent drug loading and easy functionalization properties, which have been extensively integrated into the construction of engineered drug delivery nanosystems for TME normalization therapy. It has become a commanding point in the field of anti-tumor therapy. This review intends to present and analyze advanced nanotechnology strategies for normalizing TME from 7 different aspects including the reprogramming of extracellular matrix (ECM), cancer-associated fibroblasts (CAFs), abnormal blood vasculatures, hypoxia, tumor acidosis, tumor-associated macrophages (TAMs) and tumor immune tolerance microenvironment based on the various engineered drug delivery nanosystems. It also discusses the currently existing problems and future development trends, which are expected to be helpful for the translational application of nanomedicine in clinical cancer therapy.This work was financially supported by the National Natural Science Foundation of China (51303218, 51825302, 11472224, 11672246, 11722220, 21274169 and 81760441), the National Key Research and Development Program of China (2016YFC1100300 and 2017YFB0702603), the Fundamental Research Funds for the Central Universities (G2018KY0302 and 3102019YX01003), and the Natural Science Foundation of Shaanxi Province (2019JQ-347)

Nucleic Acids Enabled‐Interfacial Engineering for Biomarker Sensing with Distance Constraint Effects

Abstract Controlling the distance of molecular recognition and signal transduction at the nano–bio interface plays a vital role in sensing molecular interactions, which significantly impacts how a biomarker sensor performs in terms of sensitivity, specificity, detection threshold, and response time. However, conventional biosensing interfaces without the design of distance constraint show limited molecular interactions, hindering target accessibility and mass transport. Nuclei acid‐enabled engineering of biosensing interfaces facilitates highly regulated orientation and programmable density control of biomolecules, providing an effective strategy to improve the performance of biosensing platforms for early diagnosis of diseases and regulation of cellular activities. This review summarizes the recent advances in nucleic acid‐based engineering of biosensing interfaces from a unique perspective of distance constraint effects. The roles of structural nucleic acids in delicately programmed assemblies, functional nucleic acids in molecular recognition, and sensor reactions at well‐controlled distances are highlighted. Then applications of advanced biosensing platforms with the effect of distance constraint are introduced. Finally, the current challenges and future directions for developing such biosensors that can compete effectively to meet the requirements of point‐of‐care testing are also discussed

Inhibition of glycolysis-driven immunosuppression with a nano-assembly enhances response to immune checkpoint blockade therapy in triple negative breast cancer

Abstract Immune-checkpoint inhibitors (ICI) are promising modalities for treating triple negative breast cancer (TNBC). However, hyperglycolysis, a hallmark of TNBC cells, may drive tumor-intrinsic PD-L1 glycosylation and boost regulatory T cell function to impair ICI efficacy. Herein, we report a tumor microenvironment-activatable nanoassembly based on self-assembled aptamer-polymer conjugates for the targeted delivery of glucose transporter 1 inhibitor BAY-876 (DNA-PAE@BAY-876), which remodels the immunosuppressive TME to enhance ICI response. Poly β-amino ester (PAE)-modified PD-L1 and CTLA-4-antagonizing aptamers (aptPD-L1 and aptCTLA-4) are synthesized and co-assembled into supramolecular nanoassemblies for carrying BAY-876. The acidic tumor microenvironment causes PAE protonation and triggers nanoassembly dissociation to initiate BAY-876 and aptamer release. BAY-876 selectively inhibits TNBC glycolysis to deprive uridine diphosphate N-acetylglucosamine and downregulate PD-L1 N-linked glycosylation, thus facilitating PD-L1 recognition of aptPD-L1 to boost anti-PD-L1 therapy. Meanwhile, BAY-876 treatment also elevates glucose supply to tumor-residing regulatory T cells (Tregs) for metabolically rewiring them into an immunostimulatory state, thus cooperating with aptCTLA-4-mediated immune-checkpoint inhibition to abolish Treg-mediated immunosuppression. DNA-PAE@BAY-876 effectively reprograms the immunosuppressive microenvironment in preclinical models of TNBC in female mice and provides a distinct approach for TNBC immunotherapy in the clinics