In Vitro Targeted Magnetic Delivery and Tracking of Superparamagnetic Iron Oxide Particles Labeled Stem Cells for Articular Cartilage Defect Repair

To assess a novel cell manipulation technique of tissue engineering with respect to its ability to augment superparamagnetic iron oxide particles （SPIO） labeled mesenchymal stem cells （MSCs） density at a localized cartilage defect site in an in vitro phantom by applying magnetic force. Meanwhile, non-invasive imaging techniques were use to track SPIO-labeled MSCs by magnetic resonance imaging （MRI）. Human bone marrow MSCs were cultured and labeled with SPIO. Fresh degenerated human osteochondral fragments were obtained during total knee arthroplasty and a cartilage defect was created at the center. Then, the osteochondral fragments were attached to the sidewalls of culture flasks filled with phosphate-buffered saline （PBS） to mimic the human joint cavity. The SPIO-labeled MSCs were injected into the culture flasks in the presence of a 0.57 Tesla （T） magnetic force. Before and 90 min after cell targeting, the specimens underwent T2-weighted turbo spin-echo （SET2WI） sequence of 3.0 T MRI. MRI results were compared with histological findings. Macroscopic observation showed that SPIO-labeled MSCs were steered to the target region of cartilage defect. MRI revealed significant changes in signal intensity （P0.01）. HE staining exibited that a great number of MSCs formed a three-dimensional （3D） cell ＂sheet＂ structure at the chondral defect site. It was concluded that 0.57 T magnetic force permits spatial delivery of magnetically labeled MSCs to the target region in vitro. High-field MRI can serve as an very sensitive non-invasive technique for the visualization of SPIO-labeled MSCs.

The law of anti-VCAM-1 targeted microbubbles adhesion to activated endothelial cells under controlled shear flow

Microbubbles can enhance the detection in noninvasive ultrasound imaging.Recently,targeted microbubbles have been developed to selectively adhere to specific and overexpressed p molecules in endothelial cells in some pathologic conditions.However,the law of

Targeting the P2X7 receptor in microglial cells to prevent brain inflammation

Microglial cells are the key innate immune cells in the brain and they are crucial in maintaining brain parenchyma homeostasis.Under physiological conditions,microglial cells assume a ramified morphology with a small cell body and an extensive network of fine processes,which secrete neurotrophic factors and patrol the surroundings in search for pathogens and eliminate cellular debris via phagocytosis.Microglial cells express a repertoire of pattern recognition receptors(PRRs)that enable them to detect diverse danger-associated molecular patterns(DAMPs)released from damaged cells or cells under stress,or pathogen-associated molecular patterns generated by pathogens during infection.

Relevance and therapeutic potential of Cyp A targeting to block apoptosis inducing factor-mediated neuronal cell death

Programmed cell death （PCD） signaling pathways are import- ant contributors to acute neurological insults such as hypox- ic-ischemic brain damage, traumatic brain injury, stroke etc. The pathogenesis of all these diseases is closely linked with ab- erration of apoptotic cell death pathways. Mitochondria play a crucial role during PCD, acting as both sensors of death signals, and as initiators of biochemical path- ways, which cause cell death （Bras et al., 2005）. Cytochrome c was the firstly identified apoptogenic factor released from mitochondria into the cytosol, where it induces apoptosome formation through the activation of caspases. Other proteins, such as apoptosis inducing factor （AIF）, have been subsequently identified as mitochondrial released factors. AIF contributes to apoptotic nuclear DNA damage （Bras et al., 2005）. in a caspase-independent way

Hypothesis of design of biological cell robot as human immunodeficiency virus vaccine

High genetic variability of human immunodeficiency virus(HIV)has been a major intractable challenge to the practical design of vaccines.But a recent pioneer study published in PNAS Xenobots,is likely to revolutionize HIV prevention as it presented the world's first living robot made of cells.In the advent of this discovery,we herein discuss the possibility of using living biological cell robots to target HIV-infected T lymphocytes,and the prospects of this approach being a new HIV vaccine.We capture the current research status and trend of advances in biological cell robots'design as a new HIV vaccine.The key differences between this novel vaccine and other HIV vaccines are highlighted.

Targeted suppression of miRNA-21 inhibit K562 cells growth through PTEN-PI3K/AKT signaling pathway

Objective To investigate the K562 cells biological function and related molecular changes in PTEN-PI3K/AKT signaling pathway of leukemia K562 cells by inhibiting the miRNA-21 expression to explore its pathogenesis of leukemia.Methods The chemical synthetic miRNA-

Water–soluble and polarity–sensitive near–infrared fluorescent probe for long–time specific cancer cell membranes imaging and C. Elegans label

A novel D–π –A structure and near–infrared fluorescent probe(DCITT) with high polarity sensitivity and membrane targeting was reported. The fluorescent spectra of DCITT were polarity dependent and Stokes shift was greater than 300 nm. Due to its high fluorescence quantum yield, low cytotoxicity and photostability, DCITT could be used as a labeling probe in multicellular organisms. In particular, DCITT effectively distinguished tumor cells from normal cells because it could specifically light up the cancer cells membrane based on strong red fluorescence for a long time. On this basis, a polar–sensitive cell membrane probe is developed to differentiate tumor cells from normal cells, which provides an idea and method for the early diagnosis of tumor at cellular level.

Controlling self-assembling and tumor cell-targeting of protein-only nanoparticles through modular protein engineering

Modular protein engineering is suited to recruit complex and multiple functionalities in single-chain polypeptides. Although still unexplored in a systematic way, it is anticipated that the positioning of functional domains would impact and refine these activities, including the ability to organize as supramolecular entities and to generate multifunctional protein materials. To explore this concept, we have repositioned functional segments in the modular protein T22-GFP-H6 and characterized the resulting alternative fusions. In T22-GFP-H6, the combination of T22 and H6 promotes selfassembling as regular nanoparticles and selective binding and internalization of this material in CXCR4-overexpressing tumor cells, making them appealing as vehicles for selective drug delivery. The results show that the pleiotropic activities are dramatically affected in module-swapped constructs, proving the need of a carboxy terminal positioning of H6 for protein self-assembling, and the accommodation of T22 at the amino terminus as a requisite for CXCR4^+ cell binding and internalization. Furthermore, the failure of self-assembling as regular oligomers reduces cellular penetrability of the fusions while keeping the specificity of the T22-CXCR4 interaction.All these data instruct how multifunctional nanoscale protein carriers can be designed for smart, protein-driven drug delivery, not only for the treatment of CXCR4^+ human neoplasias, but also for the development of anti-HIV drugs and other pathologies in which CXCR4 is a relevant homing marker.

Human Ebola virus infection in West Africa: a review of available therapeutic agents that target different steps of the life cycle of Ebola virus

The recent outbreak of the human Zaire ebolavirus(EBOV)epidemic is spiraling out of control in West Africa.Human EBOV hemorrhagic fever has a case fatality rate of up to 90%.The EBOV is classified as a biosafety level 4 pathogen and is considered a category A agent of bioterrorism by Centers for Disease Control and Prevention,with no approved therapies and vaccines available for its treatment apart from supportive care.Although several promising therapeutic agents and vaccines against EBOV are undergoing the Phase I human trial,the current epidemic might be outpacing the speed at which drugs and vaccines can be produced.Like all viruses,the EBOV largely relies on host cell factors and physiological processes for its entry,replication,and egress.We have reviewed currently available therapeutic agents that have been shown to be effective in suppressing the proliferation of the EBOV in cell cultures or animal studies.Most of the therapeutic agents in this review are directed against non-mutable targets of the host,which is independent of viral mutation.These medications are approved by the Food and Drug Administration(FDA)for the treatment of other diseases.They are available and stockpileable for immediate use.They may also have a complementary role to those therapeutic agents under development that are directed against the mutable targets of the EBOV.

Biomimetic Recognition-Based Bioorthogonal Host-Guest Pairs for Cell Targeting and Tissue Imaging in Living Animals

Bioconjugation methods offer very important tools in studying biological systems.Synthetic host-guest pairs provide an alternative and complementary conjugation method to bioorthogonal reactions and biological association pairs.Nevertheless,macrocyclic hosts that can be used for in situ capture are limited and often rely on extremely high binding affinities.Herein,we report an alternative bioorthogonal host-guest pair that relies on highly selective molecular recognition in water.The host,namely amide naphthotube,possesses a biomimetic cavity with inward-directing hydrogen bonding sites and shows selective and strong binding to the guest(2-phenyl pyrimidine)even in biological media.Through anchoring the tetraphenyl ethylene-modi fied hosts to cell surfaces,the bioorthogonal host-guest pair can be applied in cell surface recognition,cell-cell interactions,and tissue imaging in mice.The bioorthogonality is originated from the high binding selectivity of the biomimetic macrocyclic host,which is different from other known host-guest pairs that have been applied in biological systems.This research provides a new noncovalent bioconjugation tool and a new concept for designing bioorthogonal host-guest pairs for biological applications.

Genome-wide Analysis of Smad Targets Reveals the Role of BMP Signaling in Embryonic Stem Cell Fate Determination

Embryonic stem (ES) cells are under precise control of both intrinsic self-renewal gene regulatory network and extrinsic growth factor-triggered signaling cascades.

Recent progress in application of nanovaccines for enhancing mucosal immune responses

Mucosal vaccines that stimulate both mucosal and systemic immune responses are desirable,as they could prevent the invading pathogens at their initial infection sites in a convenient and userfriendly way. Nanovaccines are receiving increasing attention for mucosal vaccination due to their merits in overcoming mucosal immune barriers and in enhancing immunogenicity of the encapsulated antigens.Herein, we summarized several nanovaccine strategies that have been reported for enhancing mucosal immune responses, including designing nanovaccines that have superior mucoadhesion and mucus penetration capacity, designing nanovaccines with better targeting efficiency to M cells or antigen-presenting cells, and co-delivering adjuvants by using nanovaccines. The reported applications of mucosal nanovaccines were also briefly discussed, including prevention of infectious diseases, and treatment of tumors and autoimmune diseases. Future research progresses in mucosal nanovaccines may promote the clinical translation and application of mucosal vaccines.

Real-time SERS monitoring anticancer drug release along with SERS/MR imaging for pH-sensitive chemo-phototherapy

In situ and real-time monitoring of responsive drug release is critical for the assessment of pharmacodynamics in chemotherapy.In this study,a novel pH-responsive nanosystem is proposed for real-time monitoring of drug release and chemo-phototherapy by surface-enhanced Raman spectroscopy(SERS).The Fe3O4@Au@Ag nanoparticles(NPs)deposited graphene oxide(GO)nanocomposites with a high SERS activity and stability are synthesized and labeled with a Raman reporter 4-mercaptophenylboronic acid(4-MPBA)to form SERS probes(GO-Fe3O4@Au@Ag-MPBA).Furthermore,doxorubicin(DOX)is attached to SERS probes through a pH-responsive linker boronic ester(GO-Fe3O4@Au@Ag-MPBA-DOX),accompanying the 4-MPBA signal change in SERS.After the entry into tumor,the breakage of boronic ester in the acidic environment gives rise to the release of DOX and the recovery of 4-MPBA SERS signal.Thus,the DOX dynamic release can be monitored by the real-time changes of 4-MPBA SERS spectra.Additionally,the strong T2 magnetic resonance(MR)signal and NIR photothermal transduction efficiency of the nanocomposites make it available for MR imaging and photothermal therapy(PTT).Altogether,this GO-Fe3O4@Au@Ag-MPBA-DOX can simultaneously fulfill the synergistic combination of cancer cell targeting,pH-sensitive drug release,SERS-traceable detection and MR imaging,endowing it great potential for SERS/MR imaging-guided efficient chemo-phototherapy on cancer treatment.

Self-assembling protein nanocarrier for selective delivery of cytotoxic polypeptides to CXCR4^(+) head and neck squamous cell carcinoma tumors

Loco-regional recurrences and distant metastases represent the main cause of head and neck squamous cell carcinoma(HNSCC) mortality. The overexpression of chemokine receptor 4(CXCR4) in HNSCC primary tumors associates with higher risk of developing loco-regional recurrences and distant metastases, thus making CXCR4 an ideal entry pathway for targeted drug delivery. In this context, our group has generated the self-assembling protein nanocarrier T22-GFP-H6, displaying multiple T22 peptidic ligands that specifically target CXCR4. This study aimed to validate T22-GFP-H6 as a suitable nanocarrier to selectively deliver cytotoxic agents to CXCR4^(+)tumors in a HNSCC model. Here we demonstrate that T22-GFP-H6 selectively internalizes in CXCR4^(+)HNSCC cells, achieving a high accumulation in CXCR4^(+)tumors in vivo, while showing negligible nanocarrier distribution in non-tumor bearing organs. Moreover, this T22-empowered nanocarrier can incorporate bacterial toxin domains to generate therapeutic nanotoxins that induce cell death in CXCR4-overexpressing tumors in the absence of histological alterations in normal organs. Altogether, these results show the potential use of this T22-empowered nanocarrier platform to incorporate polypeptidic domains of choice to selectively eliminate CXCR4^(+)cells in HNSCC. Remarkably, to our knowledge, this is the first study testing targeted proteinonly nanoparticles in this cancer type, which may represent a novel treatment approach for HNSCC patients.

Efficacy of Aidi Injection(艾迪注射液)on Overexpression of P-Glycoprotein Induced by Vinorelbine and Cisplatin Regimen in Patients with Non-Small Cell Lung Cancer

Objective：To investigate the efficacy of Aidi Injection（艾迪注射液） on overexpression of P-glycoprotein（P-gp） induced by vinorelbine and cisplatin（NP） regimen in patients with non-small cell lung cancer（NSCLC）, and study the difference between intravenous administration and targeting intratumor administration of Aidi Injection with thoracoscope. Methods：Totally 150 patients with NSCLC were randomly assigned to the control group, the intravenous group and the intratumor group by the random envelope method, 50 cases in each group. The patients were treated with NP regimen（2 cycles）, NP regimen（2 cycles） plus Aidi intravenous injection, or NP regimen（2 cycles） plus Aidi intratumor injection with thoracoscope, respectively for 6 weeks. The clinical efficacy was observed based on Response Evaluation Criteria in Solid Tumors（RECIST） rules, the expression of P-gp in the tumor tissue was tested before, 3 and 6 weeks after treatment, the safety was evaluated by monitoring the toxicity in the process of treatment, and the progressionfree survival（PFS） was measured. Results：Fifteen cases dropped out because of the irreconcilable conditions which had no relationship with the treatment, 4 in the control group, 5 in the intravenous group, and 6 in the intratumor group, respectively. Compared with the control group, the response rates（complete remission ＋ partial response） and the disease control rates（complete remission ＋ partial response ＋ stable disease） were significantly higher, the P-gp expressions were significantly decreased after 3 and 6 weeks of treatment, and the Kaplan-Meier survival curves of PFS were significantly longer in the intravenous and intratumor groups（P〈0.05 or P〈0.01）, and the intratumor group showed better effects than the intravenous group（P〈0.05 or P〈0.01）. Compared with the control group, the occurrences of rash, nausea and leukocytopenia were significantly decreased in the intravenous and intratumor groups（P〈0.05）, but without significant difference between the intravenous and intratumor groups（P〉0.05）. Conclusion：Aidi Injection not only improves the efficacy of NP regime, but also has the function of reducing adverse events and preventing against overexpression of P-gp induced by chemotherapy of NP regimen.