pRNA:一种安全、稳定、大容量的基因治疗分子载体

疾病的基因治疗需要安全、高效、靶向性的分子载体。通过对pRNA分子的结构和作用机理的研究,发现pRNA分子极易穿过细胞膜,有多个结合位点,能有效转导多个外源分子进入靶细胞,在体内几乎不引起免疫反应,而且可能通过设计多功能靶向复合物将疾病的检测和治疗有机的结合在一起,成为一种理想的基因治疗型载体。     

Polymers in small-interfering RNA delivery

This review will cover the current strategies that are being adopted to efficiently deliver small interfering RNA using nonviral vectors, including the use of polymers such as polyethylenimine, poly(lactic-co-glycolic acid), polypeptides, chitosan, cyclodextrin, dendrimers, and polymers-containing different nanoparticles. The article will provide a brief and concise account of underlying principle of these polymeric vectors and their structural and functional modifications which were intended to serve different purposes to affect efficient therapeutic outcome of small-interfering RNA delivery. The modifications of these polymeric vectors will be discussed with reference to stimuli-responsiveness, target specific delivery, and incorporation of nanoconstructs such as carbon nanotubes, gold nanoparticles, and silica nanoparticles. The emergence of small-interfering RNA as the potential therapeutic agent and its mode of action will also be mentioned in a nutshell.     

Aptamer-based molecular imaging

Molecular imaging has greatly advanced basic biology and translational medicine through visualization and quantification of single/multiple molecular events temporally and spatially in a cellular context and in living organisms. Aptamers, short single-stranded nucleic acids selected in vitro to bind a broad range of target molecules avidly and specifically, are ideal molecular recognition elements for probe development in molecular imaging. This review summarizes the current state of aptamer-based biosensor development (probe design and imaging modalities) and their application in imaging small molecules, nucleic acids and proteins mostly in a cellular context with some animal studies. The article is concluded with a brief discussion on the perspective of aptamer-based molecular imaging.     

Cellular delivery of impermeable effector molecules in the form of conjugates with peptides capable of mediating membrane translocation.

Most molecules that are not actively imported by living cells are impermeable to cell membranes, including practically all macromolecules and even many small molecules whose physicochemical properties prevent passive membrane diffusion. The use of peptide vectors capable of transporting such molecules into cells in the form of covalent conjugates has become an increasingly attractive solution to this problem. Not only has this technology permitted the study of modulating intracellular target proteins, but it has also gained importance as an alternative to conventional cellular transfection with oligonucleotides. Peptide vectors derived from viral, bacterial, insect, and mammalian proteins endowed with membrane translocation properties have now been proposed as delivery vectors. These are discussed comprehensively and critically in terms of relative utility, applications to compound classes and specific molecules, and relevant conjugation chemistry. Although in most cases the mechanisms of membrane translocation are still unclear, physicochemical studies have been carried out with a number of peptide delivery vectors. Unifying and distinguishing mechanistic features of the various vectors are discussed. Until a few years ago speculations that it might be possible to deliver peptides, proteins, oligonucleotides, and impermeable small molecules with the aid of cellular delivery peptides not only to target cells in vitro, but in vivo, was received with scepticism. However, the first studies showing pharmacological applications of conjugates between macromolecules and peptide delivery vectors are now being reported, and therapies based on such conjugates are beginning to appear feasible.     

Visual information processing using bacteriorhodopsin-based complex LB films

Image extraction and visual information processing using bacteriorhodopsin (bR)-based bioelectronic devices is presented. Image extraction was achieved using a photoreceptor consisting of bR and spiropyran films. The undesired signals from the photoreceptor were automatically eliminated from the whole signal by spiropyran films acting as an optical noise filter that increases the target signal to an undesired signal ratio. For the information processing, the photoreceptor consisting of bR and lipid films deposited with different configurations was used and the target signals were processed to achieve the pattern recognition. The pattern recognition was based on not only the response variability of bacteriorhodopsin, induced by different film configurations, but also on the initial learning process. The input patterns were predicted by simple calculation with the known signals through the initial learning process.     

Polypeptide multilayer film co-delivers oppositely-charged drug molecules in sustained manners

The current state-of-the-art for drug-carrying biomedical devices is mostly limited to those that release a single drug. Yet there are many situations in which more than one therapeutic agent is needed. Also, most polyelectrolyte multilayer films intended for drug delivery are loaded with active molecules only during multilayer film preparation. In this paper, we present the integration of capsules as vehicles within polypeptide multilayer films for sustained release of multiple oppositely charged drug molecules using layer-by-layer nanoassembly technology. Calcium carbonate (CaCO(3)) particles were impregnated with polyelectrolytes, shelled with polyelectrolyte multilayers, and then assembled onto polypeptide multilayer films using glutaraldehyde. Capsule-integrated polypeptide multilayer films were obtained after decomposition of CaCO(3) templates. Two oppositely charged drugs were loaded into capsules within polypeptide multilayer films postpreparation based on electrostatic interactions between the drugs and the polyelectrolytes impregnated within capsules. We determined that the developed innovative capsule-integrated polypeptide multilayer films could be used to load multiple drugs of very different properties (e.g., opposite charges) any time postpreparation (e.g., minutes before surgical implantation inside an operating room), and such capsule-integrated films allowed simultaneous delivery of two oppositely charged drug molecules and a sustained (up to two weeks or longer) and sequential release was achieved.     

Clinical development of anti-RANKL therapy

The receptor activator of nuclear factor-kappaB ligand (RANKL), its cognate receptor RANK, and its natural decoy receptor osteoprotegerin have been identified as the final effector molecules of osteoclastic bone resorption. This has provided an ideal target for therapeutic interventions in metabolic bone disease. As described in previous reviews in this supplement, RANKL signaling is required for osteoclast differentiation, activation, and survival. Furthermore, in vivo inhibition of RANKL leads to immediate osteoclast apoptosis, and there are no in vivo models of bone resorption that are refractory to RANKL inhibition. Thus, the only step remaining in the development of a clinical intervention is the generation of a safe, effective, and specific drug that can inhibit RANKL in humans. Here we review the clinical development of denosumab (formerly known as AMG 162), which is a fully human mAb directed against RANKL. This discussion includes the breadth of 21 human studies that have led to the current phase 3 clinical trials seeking approval for use of this agent to treat postmenopausal women with low bone mineral density (osteoporosis) and patients with metastatic lytic bone lesions (multiple myeloma, and prostate and breast cancer).     

Mechanisms of arthropod transmission of plant and animal viruses.

A majority of the plant-infecting viruses and many of the animal-infecting viruses are dependent upon arthropod vectors for transmission between hosts and/or as alternative hosts. The viruses have evolved specific associations with their vectors, and we are beginning to understand the underlying mechanisms that regulate the virus transmission process. A majority of plant viruses are carried on the cuticle lining of a vector's mouthparts or foregut. This initially appeared to be simple mechanical contamination, but it is now known to be a biologically complex interaction between specific virus proteins and as yet unidentified vector cuticle-associated compounds. Numerous other plant viruses and the majority of animal viruses are carried within the body of the vector. These viruses have evolved specific mechanisms to enable them to be transported through multiple tissues and to evade vector defenses. In response, vector species have evolved so that not all individuals within a species are susceptible to virus infection or can serve as a competent vector. Not only are the virus components of the transmission process being identified, but also the genetic and physiological components of the vectors which determine their ability to be used successfully by the virus are being elucidated. The mechanisms of arthropod-virus associations are many and complex, but common themes are beginning to emerge which may allow the development of novel strategies to ultimately control epidemics caused by arthropod-borne viruses.     

Identifying Unexpected Therapeutic Targets via Chemical-Protein Interactome

Drug medications inevitably affect not only their intended protein targets but also other proteins as well. In this study we examined the hypothesis that drugs that share the same therapeutic effect also share a common therapeutic mechanism by targeting not only known drug targets, but also by interacting unexpectedly on the same cryptic targets. By constructing and mining an Alzheimer''s disease (AD) drug-oriented chemical-protein interactome (CPI) using a matrix of 10 drug molecules known to treat AD towards 401 human protein pockets, we found that such cryptic targets exist. We recovered from CPI the only validated therapeutic target of AD, acetylcholinesterase (ACHE), and highlighted several other putative targets. For example, we discovered that estrogen receptor (ER) and histone deacetylase (HDAC), which have recently been identified as two new therapeutic targets of AD, might already have been targeted by the marketed AD drugs. We further established that the CPI profile of a drug can reflect its interacting character towards multi-protein sets, and that drugs with the same therapeutic attribute will share a similar interacting profile. These findings indicate that the CPI could represent the landscape of chemical-protein interactions and uncover “behind-the-scenes” aspects of the therapeutic mechanisms of existing drugs, providing testable hypotheses of the key nodes for network pharmacology or brand new drug targets for one-target pharmacology paradigm.     

Leveraging existing data for prioritization of the ecological risks of human and veterinary pharmaceuticals to aquatic organisms

Medicinal innovation has led to the discovery and use of thousands of human and veterinary drugs. With this comes the potential for unintended effects on non-target organisms exposed to pharmaceuticals inevitably entering the environment. The impracticality of generating whole-organism chronic toxicity data representative of all species in the environment has necessitated prioritization of drugs for focused empirical testing as well as field monitoring. Current prioritization strategies typically emphasize likelihood for exposure (i.e. predicted/measured environmental concentrations), while incorporating only rather limited consideration of potential effects of the drug to non-target organisms. However, substantial mammalian pharmacokinetic and mechanism/mode of action (MOA) data are produced during drug development to understand drug target specificity and efficacy for intended consumers. An integrated prioritization strategy for assessing risks of human and veterinary drugs would leverage available pharmacokinetic and toxicokinetic data for evaluation of the potential for adverse effects to non-target organisms. In this reiview, we demonstrate the utility of read-across approaches to leverage mammalian absorption, distribution, metabolism and elimination data; analyse cross-species molecular target conservation and translate therapeutic MOA to an adverse outcome pathway(s) relevant to aquatic organisms as a means to inform prioritization of drugs for focused toxicity testing and environmental monitoring.     

Costimulatory molecules as targets for the induction of transplantation tolerance

Transplantation is the only cure for end-stage organ failure. Transplanted tissues are usually recognized by the immune system as foreign and are rapidly rejected in the absence of immunosuppression. Transplanted organs between genetically distinct individuals are termed allografts and their acute rejection is orchestrated by the activation of allospecific T cells. To prevent acute allograft rejection, current therapies suppress all T cells irrespective of their specificities and must be taken life-long, leaving patients with decreased defenses against infectious agents and cancers. The goal in transplantation research is to develop therapies with the capacity to induce graft-specific tolerance. Ideal therapies should be of short duration and target only alloreactive T cells, leaving other T cells competent to fight infections and cancers. Researchers have studied the mechanisms of activation/regulation of T cells in the hopes that manipulation of these pathways may facilitate the induction of tolerance. Activation of T cells requires recognition by the T cell receptor (TCR) of antigenic peptides presented within major histocompatibility complexes (MHC) on the surface of antigen-presenting cells (APCs). In addition, concurrent engagement of costimulatory receptors on T cells by ligands on APCs is also required for optimal T cell responses, such that the ultimate outcome of TCR engagement reflects the relative sum of multiple positive and negative costimulatory signals. Targeting costimulatory receptor/ligand pairs has been used effectively to induce allograft tolerance in specific rodent transplantation models. This strategy has however been less effective in larger mammals. In this review, we will summarize the different reagents used to target costimulatory molecules, their effects, and the possible reasons limiting their efficacy in higher order mammals.     

Mechanisms of Arthropod Transmission of Plant and Animal Viruses

A majority of the plant-infecting viruses and many of the animal-infecting viruses are dependent upon arthropod vectors for transmission between hosts and/or as alternative hosts. The viruses have evolved specific associations with their vectors, and we are beginning to understand the underlying mechanisms that regulate the virus transmission process. A majority of plant viruses are carried on the cuticle lining of a vector’s mouthparts or foregut. This initially appeared to be simple mechanical contamination, but it is now known to be a biologically complex interaction between specific virus proteins and as yet unidentified vector cuticle-associated compounds. Numerous other plant viruses and the majority of animal viruses are carried within the body of the vector. These viruses have evolved specific mechanisms to enable them to be transported through multiple tissues and to evade vector defenses. In response, vector species have evolved so that not all individuals within a species are susceptible to virus infection or can serve as a competent vector. Not only are the virus components of the transmission process being identified, but also the genetic and physiological components of the vectors which determine their ability to be used successfully by the virus are being elucidated. The mechanisms of arthropod-virus associations are many and complex, but common themes are beginning to emerge which may allow the development of novel strategies to ultimately control epidemics caused by arthropod-borne viruses.     

Cellular uptake and intracellular fate of antisense oligonucleotides

Antisense oligonucleotides with sequences complementary to a given genetic target can enter cells in sufficient quantities to selectively inhibit gene expression. Thus, they have a potential therapeutic use in preventing undesirable gene expression in diseases such as cancer and AIDS. However, it is remarkable that these molecules, which have high molecular weights and are often charged, gain entry to cells at all. In this article, we review the possible mechanisms by which oligonucleotides enter cells and their subsequent intracellular fates. We also discuss current approaches for improving cellular uptake and delivery of antisense nucleic acids to their intended targets.     

The enzyme as drug: application of enzymes as pharmaceuticals

Enzymes as drugs have two important features that distinguish them from all other types of drugs. First, enzymes often bind and act on their targets with great affinity and specificity. Second, enzymes are catalytic and convert multiple target molecules to the desired products. These two features make enzymes specific and potent drugs that can accomplish therapeutic biochemistry in the body that small molecules cannot. These characteristics have resulted in the development of many enzyme drugs for a wide range of disorders.     

综述——纳米材料与药物输递：基因治疗药物输递系统的研究现状及发展趋势

基因治疗是一种有效的治疗方法,可用于治疗多种严重威胁人类健康的疾病．然而,裸露的基因治疗药物存在易被核酶降解、细胞内吞效果差和细胞靶向能力差等缺点．因此,需要寻求合适的载体,将基因治疗药物有效地输递到靶细胞,实现高效的基因治疗．本文主要综述了近年来基因治疗药物输递系统的研究进展,分别总结和阐述了病毒载体,脂质体、聚合物和树状大分子等非病毒载体,以及具有示踪功能的输递系统的特点及研究和发展现状．     

Dynamic and cellular interactions of nanoparticles in vascular-targeted drug delivery

Vascular-targeted drug delivery systems could provide more efficient and effective pharmaceutical interventions for treating a variety of diseases including cardiovascular, pulmonary, inflammatory, and malignant disorders. However, several factors must be taken into account when designing these systems. The diverse blood hemodynamics and rheology, and the natural clearance process that tend to decrease the circulation time of foreign particles all lessen the probability of successful carrier interaction with the vascular wall. An effective vascular-targeted drug delivery system must be able to navigate through the bloodstream while avoiding immune clearance, attach to the vascular wall, and release its therapeutic cargo at the intended location. This review will summarize and analyze current literature reporting on (1) nanocarrier fabrication methods and materials that allow for optimum therapeutic encapsulation, protection, and release; (2) localization and binding dynamics of nanocarriers as influenced by hemodynamics and blood rheology in medium-to-large vessels; (3) blood cells' responses to various types of nanocarrier compositions and its effects on particle circulation time; and (4) properties that affect nanocarrier internalization at the target site.     

An opportunistic route to success: Towards a change of paradigm to fully exploit the potential of cell-penetrating peptides

About 25 years ago it was demonstrated that certain peptides possess the ability to cross the plasma membrane. This led to the development of cell-penetrating peptides (CPPs) as vectors to mediate the cellular entry of (macro-)molecules that do not show cell entry by themselves. Nonetheless, in spite of an early bloom of promising pre-clinical studies, not a single CPP-based drug has been approved, yet. It is a paradigm in CPP research that the peptides are taken up by virtually all cells. In exploratory research and early preclinical development, this assumption guides the choice of the therapeutic target. However, while this indiscriminatory uptake may be the case for tissue culture experiments, in an organism this is clearly not the case. Biodistribution analyses demonstrate that CPPs only target a very limited number of cells and many tissues are hardly reached at all. Here, we review biodistribution analyses of CPPs and CPP-based drug delivery systems. Based on this analysis we propose a paradigm change towards a more opportunistic approach in CPP research. The application of CPPs should focus on those pathophysiologies for which the relevant target cells have been shown to be reached in vivo.     

Targeted Gene Delivery by Intravenous Injection of Retroviral Vectors

Specifically and effectively directing a therapeutic gene to its intended site of action is a critical issue for translation of basic genomics to clinical gene therapy. Delivering gene therapy vectors to specific cells or tissues through intravenous injection is the most desirable method for this purpose. In 2001, we reported successful targeted gene transduction in vitro utilizing both oncoretroviral and lentiviral vectors pseudotyped with a chimeric Sindbis virus envelope (ZZ SINDBIS). However, these pseudotypes mediated non-specific gene transduction to liver and spleen in vivo. To address this problem we generated the modified ZZ SINDBIS (termed m168) with significantly less non-specific infectivity. To investigate the ability of m168 pseudotyped lentiviral vector to mediate targeted gene transduction in vivo, we utilized a metastatic tumor model by using mouse melanoma cells engineered to express human P-glycoprotein. We administered the m168 pseudotyped vector conjugated with anti-P-glycoprotein antibody into the mice intravenously to target metastatic melanoma. The m168 pseudotyped vector selectively infected metastatic melanoma cells demonstrating successful targeted gene transduction in vivo. Targeting technology based upon m168 can be further modified for application not only to cancer but also potentially to genetic, neurologic, infectious and immune diseases, thereby expanding the future application of gene therapy.