Osteopontin targeted theranostic nanoprobes for laser-induced synergistic regression of vulnerable atherosclerotic plaques.

Vulnerable atherosclerotic plaque (VASPs) is the major pathological cause of acute cardiovascular event. Early detection and precise intervention of VASP hold great clinical significance, yet remain a major challenge. Photodynamic therapy (PDT) realizes potent ablation efficacy under precise manipulation of laser irradiation. In this study, we constructed theranostic nanoprobes (NPs), which could precisely regress VASPs through a cascade of synergistic events triggered by local irradiation of lasers under the guidance of fluorescence/MR imaging. The NPs were formulated from human serum albumin (HSA) conjugated with a high affinity-peptide targeting osteopontin (OPN) and encapsulated with photosensitizer IR780 and hypoxia-activatable tirapazamine (TPZ). After intravenous injection into atherosclerotic mice, the OPN-targeted NPs demonstrated high specific accumulation in VASPs due to the overexpression of OPN in activated foamy macrophages in the carotid artery. Under the visible guidance of fluorescence and MR dual-model imaging, the precise near-infrared (NIR) laser irradiation generated massive reactive oxygen species (ROS), which resulted in efficient plaque ablation and amplified hypoxia within VASPs. In response to the elevated hypoxia, the initially inactive TPZ was successively boosted to present potent biological suppression of foamy macrophages. After therapeutic administration of the NPs for 2 weeks, the plaque area and the degree of carotid artery stenosis were markedly reduced. Furthermore, the formulated NPs displayed excellent biocompatibility. In conclusion, the developed HSA-based NPs demonstrated appreciable specific identification ability of VASPs and realized precise synergistic regression of atherosclerosis.

Bioimaging guided pharmaceutical evaluations of nanomedicines for clinical translations.

Nanomedicines (NMs) have emerged as an efficient approach for developing novel treatment strategies against a variety of diseases. Over the past few decades, NM formulations have received great attention, and a large number of studies have been performed in this field. Despite this, only about 60 nano-formulations have received industrial acceptance and are currently available for clinical use. Their in vivo pharmaceutical behavior is considered one of the main challenges and hurdles for the effective clinical translation of NMs, because it is difficult to monitor the pharmaceutic fate of NMs in the biological environment using conventional pharmaceutical evaluations. In this context, non-invasive imaging modalities offer attractive solutions, providing the direct monitoring and quantification of the pharmacokinetic and pharmacodynamic behavior of labeled NMs in a real-time manner. Imaging evaluations have great potential for revealing the relationship between the physicochemical properties of NMs and their pharmaceutical profiles in living subjects. In this review, we introduced imaging techniques that can be used for in vivo NM evaluations. We also provided an overview of various studies on the influence of key parameters on the in vivo pharmaceutical behavior of NMs that had been visualized in a non-invasive and real-time manner.

Stimuli-responsive polymeric nanomaterials for rheumatoid arthritis therapy.

Rheumatoid arthritis (RA) is a long-term inflammatory disease derived from an autoimmune disorder of the synovial membrane. Current therapeutic strategies for RA mainly aim to hamper the macrophages' proliferation and reduce the production of pro-inflammatory cytokines. Therefore, the accumulation of therapeutic agents targeted at the inflammatory site should be a crucial therapeutic strategy. Nowadays, the nanocarrier system incorporated with stimuli-responsive property is being intensively studied, showing the potentially tremendous value of specific therapy. Stimuli-responsive (i.e., pH, temperature, light, redox, and enzyme) polymeric nanomaterials, as an important component of nanoparticulate carriers, have been intensively developed for various diseases treatment. A survey of the literature suggests that the use of targeted nanocarriers to deliver therapeutic agents (nanotherapeutics) in the treatment of inflammatory arthritis remains largely unexplored. The lack of suitable stimuli-sensitive polymeric nanomaterials is one of the limitations. Herein, we provide an overview of drug delivery systems prepared from commonly used stimuli-sensitive polymeric nanomaterials and some inorganic agents that have potential in the treatment of RA. The current situation and challenges are also discussed to stimulate a novel thinking about the development of nanomedicine.

Nrp-1 receptor targeting peptide-functionalized TPGS micellar nanosystems to deliver 10-hydroxycampothecin for enhanced cancer chemotherapy.

Mitochondria are considered the power house of cells where ATP is generated for cellular metabolism, and they also act as a crucial regulator of the intrinsic apoptosis pathway. During ATP synthesis, reactive oxygen species (ROS) are produced as secondary products. Overproduction of ROS can promote mitochondrial DNA mutation, dysfunction and depolarization of the mitochondrial membrane, ultimately resulting in cell death. Therefore, the destruction of mitochondria would be an effective therapeutic approach to kill malignant tumors. Herein, we formulated a PEGylated α-TOS polymeric micellar system loaded with 10-hydroxycamptothecin (HCPT) drug to inhibit the nuclear topoisomerase I enzyme and disrupt the mitochondrial membrane to induce apoptosis. In addition, tumor-penetrating CRGDK peptide-functionalized TPGS2k specifically bound to the Nrp-1 receptor to facilitate higher cell uptake of polymeric micelles by tumor cells. Experimental studies confirmed that HCPT-loaded and peptide-functionalized TPGS2k-TOS micelles (HLPFTTM) showed an enhanced anti-cancer effect in A549 cancer cells.

P-gp Inhibition and Mitochondrial Impairment by Dual-Functional Nanostructure Based on Vitamin E Derivatives To Overcome Multidrug Resistance.

Vitamin E derivatives possess many essential features for drug-delivery applications, such as biocompatibility, stability, improvement of water solubility of hydrophobic compounds, anticancer activity, and the ability to overcome multidrug resistance (MDR). Herein, vitamin E derivatives are used to overcome MDR through a combined P-glycoprotein (P-gp) inhibition and mitochondrial impairment strategy. A novel nanomicellar drug-delivery system as a carrier for doxorubicin (DOX) was developed, in which d-α-tocopheryl polyethylene glycol 1000 succinate was used as a P-gp inhibitor, α-tocopheryl succinate was introduced as a mitochondrial disrupting agent, and d-α-tocopheryl polyethylene glycol 2000 succinate was used as the main building block of micelles. The optimal ratio between the components of the nanocarrier was determined. The resultant DOX-loaded mixed micelles exhibited a suitable size of 52.08 nm, high drug-loading encapsulation efficiency (>98%), high stability, and pH-dependent drug release. In vitro experiments demonstrated a significantly increased cytotoxic activity of DOX-loaded mixed micelles against resistant MCF-7/Adr cells (45-fold higher than DOX after 48 h of treatment). In vivo studies revealed superior antitumor efficiency with less cardio- and hepatotoxicities of DOX-loaded micelles compared with that of free DOX. These results highlight that the developed DOX-loaded mixed micelles have a promising potential to overcome MDR in chemotherapy for clinical usage.

Nanoscale Polymersomes as Anti-Cancer Drug Carriers Applied for Pharmaceutical Delivery.

Polymersomes are self-assembled nano-vesicles composed of amphiphilic block copolymers. These building blocks can be selected from a large number of hydrophilic and hydrophobic polymers in order to achieve required properties of the final system, such as biodegradability, sustainable and multiple stimuli-response drug release, long blood circulation, and low toxicity. Moreover, the surface of polymersomes can be functionalized to induce targeting character. Polymersomes are able to encapsulate a broad range of hydrophilic or/and hydrophobic molecules either in the aqueous core or membrane bilayer, respectively. In addition, colloidal stability and low membrane fluidity make polymersomes attractive nano-sized drug carriers. The review describes polymersomes compositions, their applications in pharmaceutical delivery, and preparation methods.

Targeting tumor microenvironment with PEG-based amphiphilic nanoparticles to overcome chemoresistance.

Multidrug resistance is one of the biggest obstacles in the treatment of cancer. Recent research studies highlight that tumor microenvironment plays a predominant role in tumor cell proliferation, metastasis, and drug resistance. Hence, targeting the tumor microenvironment provides a novel strategy for the evolution of cancer nanomedicine. The blooming knowledge about the tumor microenvironment merging with the design of PEG-based amphiphilic nanoparticles can provide an effective and promising platform to address the multidrug resistant tumor cells. This review describes the characteristic features of tumor microenvironment and their targeting mechanisms with the aid of PEG-based amphiphilic nanoparticles for the development of newer drug delivery systems to overcome multidrug resistance in cancer cells. FROM THE CLINICAL EDITOR: Cancer is a leading cause of death worldwide. Many cancers develop multidrug resistance towards chemotherapeutic agents with time and strategies are urgently needed to combat against this. In this review article, the authors discuss the current capabilities of using nanomedicine to target the tumor microenvironments, which would provide new insight to the development of novel delivery systems for the future.