Chemical Components for the Design of Temperature-Responsive Vesicles as Cancer Therapeutics

Thermosensitive Liposomal Codelivery of HSA-Paclitaxel and HSA-Ellagic Acid Complexes for Enhanced Drug Perfusion and Efficacy Against Pancreatic Cancer

Fibrotic stroma and tumor-promoting pancreatic stellate cells (PSCs), critical characters in the pancreatic ductal adenocarcinoma (PDA) microenvironment, promote a tumor-facilitating environment that simultaneously prevents drug penetration into tumor foci and stimulates tumor growth. Nab-PTX, a human serum albumin (HSA) nanoparticle of paclitaxel (PTX), indicates enhanced matrix penetration in PDA probably due to its small size in vivo and high affinity of HSA with secreted protein acidic and rich in cysteine (SPARC), overexpressed in the PDA stroma. However, this HSA nanoparticle shows poor drug blood retention because of its weak colloidal stability in vivo, thus resulting in insufficient drug accumulation within tumor. Encapsulating HSA nanoparticles into the internal aqueous phase of ordinary liposomes improves their blood retention and the following tumor accumulation, but the large 200 nm size and shielding of HSA in the interior might make it difficult for this hybrid nanomedicine to penetrate the fibrotic PDA matrix and promote bioavailability of the payload. In our current work, we prepared ∼9 nm HSA complexes with an antitumor drug (PTX) and an anti-PSC drug (ellagic acid, EA), and these two HSA-drug complexes were further coencapsulated into thermosensitive liposomes (TSLs). This nanomedicine was named TSL/HSA-PE. The use of TSL/HSA-PE could improve drug blood retention, and upon reaching locally heated tumors, these TSLs can rapidly release their payloads (HSA-drug complexes) to facilitate their further tumor accumulation and matrix penetration. With superior tumor accumulation, impressive matrix penetration, and simultaneous action upon tumor cells and PSCs to disrupt PSCs-PDA interaction, TSL/HSA-PE treatment combined with heat exhibited strong tumor growth inhibition and apoptosis in vivo.

Engineering thermosensitive liposome-nanoparticle hybrids loaded with doxorubicin for heat-triggered drug release

The engineering of responsive multifunctional delivery systems that combine therapeutic and diagnostic (theranostic) capabilities holds great promise and interest. We describe the design of thermosensitive liposome-nanoparticle (NP) hybrids that can modulate drug release in response to external heating stimulus. These hybrid systems were successfully engineered by the incorporation of gold, silver, and iron oxide NPs into the lipid bilayer of lysolipid-containing thermosensitive liposomes (LTSL). Structural characterization of LTSL-NP hybrids using cryo-EM and AFM revealed the incorporation of metallic NPs into the lipid membranes without compromising doxorubicin loading and retention capability. The presence of metallic NPs in the lipid bilayer reinforced bilayer retention and offered a nanoparticle concentration-dependent modulation of drug release in response to external heating. In conclusion, LTSL-NP hybrids represent a promising versatile platform based on LTSL liposomes that could further utilize the properties of the embedded NPs for multifunctional theranostic applications.

A Step-by-Step Multiple Stimuli-Responsive Nanoplatform for Enhancing Combined Chemo-Photodynamic Therapy

A robust and smart protoporphyrin-based polymer nanoplatform, which is capable of successively recognizing the variation of biological signals and reacting with them in a dynamic mode, is successfully developed. It combines the chemotherapy and photodynamic therapy in a same system, leading to a high treatment outcome while a low adverse side effect of therapeutic agent.

Evidence of Protein Adsorption in Pegylated Liposomes: Influence of Liposomal Decoration

In order to contribute to a better knowledge of the events involved in the formation of the protein corona when nanoparticles (NPs) come in contact with proteins, we report a study about the changes on the physicochemical properties of pristine, PEGylated and Cyclic Arginine-Glycine-Aspartate peptide (RGD)-functionalized large unilamelar liposomes (LUVs) or magnetoliposomes (MLs) upon incubation with Bovine Serum Albumin (BSA). The main phospholipid component of both LUVs and MLs was l-α-phosphatydylcholine (PC) or 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) with 20% of cholesterol. The most obvious indication of the interaction of BSA-nanosystems is given by changes in the hydrodynamic diameter of the particles but other evidence is needed to corroborate the process. Our findings indicate that size modification is a process that is accomplished in few hours and that is strongly dependent not only on the surface decoration but also of the lipid composition of both LUVs and MLs. Fluorescence quenching experiments as well as cryogenic transmission electron microscopy (Cryo-TEM) images assessed these changes and confirmed that although each system has to be studied in a particular way, we can establish three distinctive features that turn into more reactive systems: (a) compositions containing PC compared with their DMPC counterparts; (b) the presence of PEG and/or RGD compared to the pristine counterparts; and (c) the presence of SPIONs: MLs show higher interaction than LUVs of the same lipid composition. Consequently, PEGylation (that is supposed to make stealth NPs) actually fails in preventing complete protein binding.

Tumor-targeted nanomedicines for cancer theranostics

Chemotherapeutic drugs have multiple drawbacks, including severe side effects and suboptimal therapeutic efficacy. Nanomedicines assist in improving the biodistribution and target accumulation of chemotherapeutic drugs, and are therefore able to enhance the balance between efficacy and toxicity. Multiple types of nanomedicines have been evaluated over the years, including liposomes, polymer-drug conjugates and polymeric micelles, which rely on strategies such as passive targeting, active targeting and triggered release for improved tumor-directed drug delivery. Based on the notion that tumors and metastases are highly heterogeneous, it is important to integrate imaging properties in nanomedicine formulations in order to enable non-invasive and quantitative assessment of targeting efficiency. By allowing for patient pre-selection, such next generation nanotheranostics are useful for facilitating clinical translation and personalizing nanomedicine treatments.

Recent Advances of Using Hybrid Nanocarriers in Remotely Controlled Therapeutic Delivery

The development of hybrid biomaterials has been attracting great attention in the design of materials for biomedicine. The nanosized level of inorganic and organic or even bioactive components can be combined into a single material by this approach, which has created entirely new advanced compositions with truly unique properties for drug delivery. The recent advances in using hybrid nanovehicles as remotely controlled therapeutic delivery carriers are summarized with respect to different nanostructures, including hybrid host-guest nanoconjugates, micelles, nanogels, core-shell nanoparticles, liposomes, mesoporous silica, and hollow nanoconstructions. In addition, the controlled release of guest molecules from these hybrid nanovehicles in response to various remote stimuli such as alternating magnetic field, near infrared, or ultrasound triggers is further summarized to introduce the different mechanisms of remotely triggered release behavior. Through proper chemical functionalization, the hybrid nanovehicle system can be further endowed with many new properties toward specific biomedical applications.

Synthesis of Nanovesicular Glutathione Peroxidase Mimics with a Selenenylsulfide-Bearing Lipid

In this article, we describe the development of a nanosized-glutathione peroxidase (GPx) mimic based on liposomes of which the amphiphilic selenenylsulfide derivative (R-Se-S-R') was incorporated into a lipid membrane. A lipid membrane-compatible selenenylsulfide derivative, 1-oxo-headecyl-seleno-l-cysteine-methyl-Se-yl-S-l-penicillamine methyl ester (OHSeP), was synthesized. X-ray photoelectron spectroscopy revealed that the sulfur and selenium atoms of the OHSeP molecule formed a selenenylsulfide linkage. The use of OHSeP easily allowed the introduction of the seleno-l-cysteine (SeCys) moiety into the liposomal membranes by mixing with the phosphatidylcholines (PCs), which gave rise to the GPx-like catalytic activity because of the selenium atom in the SeCys moiety. The penicillamine moiety of the OHSeP molecule incorporated into the OHSeP/PC liposomes was thought to orient toward the outer water phase. The OHSeP/PC liposomes generated the GPx-like catalytic activity, which was ascribed to the SeCys moiety that was introduced into the PC-based liposomes. Consequently, the lipid/water interface of the liposomal membranes could possibly provide an effective colloidal platform for the development of water-soluble nanosized GPx mimics.

Photo-powered stretchable nano-containers based on well-defined vesicles formed by an overcrowded alkene switch

A novel photo-responsive nano-container was successfully constructed based on well-defined vesicles formed by an amphiphilic overcrowded alkene switch.

Photo-responsive modulation of hybrid peptide assembly, charge transfer complex formation and gelation

Light has been used as trigger for modulation of supramolecular assembly of hybrid peptides followed by charge transfer complex formation and organogelation.