Interfacial Assembly of Bacterial Microcompartment Shell Proteins in Aqueous Multiphase Systems.

Compartments are a fundamental feature of life, based variously on lipid membranes, protein shells, or biopolymer phase separation. Here, this combines self-assembling bacterial microcompartment (BMC) shell proteins and liquid-liquid phase separation (LLPS) to develop new forms of compartmentalization. It is found that BMC shell proteins assemble at the liquid-liquid interfaces between either 1) the dextran-rich droplets and PEG-rich continuous phase of a poly(ethyleneglycol)(PEG)/dextran aqueous two-phase system, or 2) the polypeptide-rich coacervate droplets and continuous dilute phase of a polylysine/polyaspartate complex coacervate system. Interfacial protein assemblies in the coacervate system are sensitive to the ratio of cationic to anionic polypeptides, consistent with electrostatically-driven assembly. In both systems, interfacial protein assembly competes with aggregation, with protein concentration and polycation availability impacting coating. These two LLPS systems are then combined to form a three-phase system wherein coacervate droplets are contained within dextran-rich phase droplets. Interfacial localization of BMC hexameric shell proteins is tunable in a three-phase system by changing the polyelectrolyte charge ratio. The tens-of-micron scale BMC shell protein-coated droplets introduced here can accommodate bioactive cargo such as enzymes or RNA and represent a new synthetic cell strategy for organizing biomimetic functionality.

Self-Assembled Redox-Sensitive Polymeric Nanostructures Facilitate the Intracellular Delivery of Paclitaxel for Improved Breast Cancer Therapy.

A two-tier approach has been proposed for targeted and synergistic combination therapy against metastatic breast cancer. First, it comprises the development of a paclitaxel (PX)-loaded redox-sensitive self-assembled micellar system using betulinic acid-disulfide-d-α-tocopheryl poly(ethylene glycol) succinate (BA-Cys-T) through carbonyl diimidazole (CDI) coupling chemistry. Second, hyaluronic acid is anchored to TPGS (HA-Cys-T) chemically through a cystamine spacer to achieve CD44 receptor-mediated targeting. We have established that there is significant synergy between PX and BA with a combination index of 0.27 at a molar ratio of 1:5. An integrated system comprising both BA-Cys-T and HA-Cys-T (PX/BA-Cys-T-HA) exhibited significantly higher uptake than PX/BA-Cys-T, indicating preferential CD44-mediated uptake along with the rapid release of drugs in response to higher glutathione concentrations. Significantly higher apoptosis (42.89%) was observed with PX/BA-Cys-T-HA than those with BA-Cys-T (12.78%) and PX/BA-Cys-T (33.38%). In addition, PX/BA-Cys-T-HA showed remarkable enhancement in the cell cycle arrest, improved depolarization of the mitochondrial membrane potential, and induced excessive generation of ROS when tested in the MDA-MB-231 cell line. An in vivo administration of targeted micelles showed improved pharmacokinetic parameters and significant tumor growth inhibition in 4T1-induced tumor-bearing BALB/c mice. Overall, the study indicates a potential role of PX/BA-Cys-T-HA in achieving both temporal and spatial targeting against metastatic breast cancer.

Amalgamated Microneedle Array Bearing Ribociclib-Loaded Transfersomes Eradicates Breast Cancer via CD44 Targeting.

HR+/HER2- metastatic breast cancer (MBC) is one of the most common and life-threatening conditions diagnosed in women. The endocrine therapy using an orally active CDK4/6 inhibitor, ribociclib (RB), is the most intriguing approach for treating HR+/HER2- MBC. However, the repeated three to six cycles of multiple dosing and non-targeted distribution of RB led to severe neutropenia; hepatobiliary, gastrointestinal, and renal toxicities, and QT interval prolongation. Here, a novel organic solvent-free HA-PVA-PVP (hyaluronic acid-polyvinyl alcohol-polyvinyl pyrrolidone) composed of a microneedle (MN) array is formulated to deliver RB, integrated with amphiphilic conjugated polymer (HA-GMS)-anchored ultradeformable transfersomes. This unique MN array efficiently crafts microchannels in the skin, allowing HA-RB-Ts to internalize into the tumor cells through lymphatic and systemic absorption and interact with CD44 both spatially and temporally with an amplification of drug release time up to 6-folds. The pharmacokinetic and tissue distribution studies portray drug concentrations within the therapeutic window as long as 48 h, facilitating thrice-a-week frequency with the lower dose, and rule out severe toxicities, with a significant reduction in 8.3-fold RB concentration in vital organs that ultimately enhances the survival rate. Thus, the novel MN system pursues a unique embeddable feature and offers an effective, self-administrable, biodegradable, and chronic treatment option for patients requiring long-term cancer treatments.

Alendronate-functionalized porous nano-crystalsomes mitigate osteolysis and consequent inhibition of tumor growth in a tibia-induced metastasis model.

Bone is one of the most prevalent sites of metastases in various epithelial malignancies, including breast cancer and this metastasis to bone often leads to severe skeletal complications in women due to its osteolytic nature. To address this, we devised a novel drug delivery approach using an Alendronate (ALN) functionalized self-assembled porous crystalsomes for concurrent targeting of Oleanolic acid (OA) and ALN (ALN + OA@NCs) to bone metastasis. Initially, the conjugation of both PEG-OA and OA-PEG-ALN with ALN and OA was achieved, and this conjugation was then self-assembled into porous crystalsomes (ALN + OA@NCs) by nanoemulsion crystallization. The reconstruction of a 3D single particle using transmission electron microscopy ensured the crystalline porous structure of ALN + OA@NCs, was well aligned with characteristic nanoparticle attributes including size distribution, polydispersity, and zeta potential. Further, ALN + OA@NCs showed enhanced efficacy in comparison to OA@NCs suggesting the cytotoxic roles of ALN towards cancer cells, followed by augmentation ROS generation (40.81%), mitochondrial membrane depolarization (57.20%), and induction of apoptosis (40.43%). We found that ALN + OA@NCs facilitated inhibiting osteoclastogenesis and bone resorption followed by inhibited osteolysis. In vivo activity of ALN + OA@NCs in the 4 T1 cell-induced tibia model rendered a reduced bone loss in the treated mice followed by restoring bone morphometric markers which were further corroborated bone-targeting effects of ALN + OA@NCs to reduce RANKL-stimulated osteoclastogenesis. Further, In vivo intravenous pharmacokinetics showed the improved therapeutic profile of the ALN + OA@NCs in comparison to the free drug, prolonging the levels of the drug in the systemic compartment by reducing the clearance culminating the higher accumulation at the tumor site. Our finding proposed that ALN + OA@NCs can effectively target and treat breast cancer metastasis to bone and its associated complications.

Peptide-Based Vectors: A Biomolecular Engineering Strategy for Gene Delivery.

From the first clinical trial by Dr. W.F. Anderson to the most recent US Food and Drug Administration-approved Luxturna (Spark Therapeutics, 2017) and Zolgensma (Novartis, 2019), gene therapy has revamped thinking and practice around cancer treatment and improved survival rates for adult and pediatric patients with genetic diseases. A major challenge to advancing gene therapies for a broader array of applications lies in safely delivering nucleic acids to their intended sites of action. Peptides offer unique potential to improve nucleic acid delivery based on their versatile and tunable interactions with biomolecules and cells. Cell-penetrating peptides and intracellular targeting peptides have received particular focus due to their promise for improving the delivery of gene therapies into cells. We highlight key examples of peptide-assisted, targeted gene delivery to cancer-specific signatures involved in tumor growth and subcellular organelle-targeting peptides, as well as emerging strategies to enhance peptide stability and bioavailability that will support long-term implementation.

Recent advances in copper sulfide nanoparticles for phototherapy of bacterial infections and cancer.

Copper sulfide nanoparticles (CuS NPs) have attracted growing interest in biomedical research due to their remarkable properties, such as their high photothermal and thermodynamic capabilities, which are ideal for anticancer and antibacterial applications. This comprehensive review focuses on the current state of antitumor and antibacterial applications of CuS NPs. The initial section provides an overview of the various approaches to synthesizing CuS NPs, highlighting the size, shape and composition of CuS NPs fabricated using different methods. In this review, the mechanisms underlying the antitumor and antibacterial activities of CuS NPs in medical applications are discussed and the clinical challenges associated with the use of CuS NPs are also addressed.

Synergistic delivery of Imatinib through multifunctional nano-crystalline capsules, in response to redox environment for improved breast cancer therapy.

Chondroitin anchored crystalline nano-capsules bearing Imatinib (IMT), and simvastatin (SMV) was developed using Poly (L-lactic acid) (PLLA) by two-step method, i.e., firstly, by synthesizing chondroitin (CSA) anchored simvastatin (SMV) using cystamine as a spacer (SMV-SS-CSA) for disulfide triggered glutathione (GSH) sensitive release and secondly, by developing phenyl boronic ester grafted Pluronic F68 (PEPF) for H2O2 responsive release. By combining these conjugates, we have prepared crystalline nano-capsules (CNs) for preferential targeting of CD44 receptors. The developed CNs were spherical when characterized through SEM, TEM, and AFM for surface morphology, while changes in particle size and crystalline structure were confirmed through Quasi-Elastic light scattering (QELS) and Wide Angle X-ray Scattering (WAXS). The enhanced cellular uptake was noted in chondroitin-modified nano-capsules IMT/SMV-SS-CSA@CNs compared to unmodified nano-capsules IMT+SMV@CNs. IMT/SMV-SS-CSA@CNs displayed significantly higher G2/M phase arrest (76.9%) than unmodified nano-capsules. The prototype formulation (IMT/SMV-SS-CSA@CNs) showed an overall improved pharmacokinetic profile in terms of both half-life and AUC0-α. When tested in the 4T1 subcutaneously injected tumor-bearing Balb/c mice model, the tumor growth inhibition rate of IMT/SMV-SS-CSA@CNs was significantly higher (91%) than the IMT+SMV combination. Overall, the findings suggest that the proposed dual responsive chondroitin-modified drug delivery could have a step forward in achieving spatial and temporal targeting at the tumor site.

Development of putrescine anchored nano-crystalsomes bearing doxorubicin and oleanolic acid: deciphering their role in inhibiting metastatic breast cancer.

Angiogenesis driven tumor initiation and progression calls for a targeted therapy. Moreover, combined chemotherapy supplements the therapy to act on the cause of concern. In this study, we aimed to develop a targeted crystalsomes approach to delineate tumor cells against normal cells. Self-assembled crystalline monodispersed nanosized polyethylene-polyethylene glycol (PE-PEG)-based hollow crystalsomes were modified with pluronylated putrescine (Put-PF) and loaded with doxorubicin (Dox), synergistically in combination with oleanolic acid (OA) to target the glypican-1 (gp-1) receptor on tumor cells. The developed crystalsomes (Put-D + O@NCs) showed increased intracellular accumulation of Dox and OA in a synergistic combination inside the MDA-MB-231 cell lines. The developed crystalsomes marked an enhanced depolarization of the mitochondrial membrane potential and cell cycle arrest leading to apoptosis. Furthermore, the proposed therapy has a greater anti-angiogenesis activity with vascular endothelial growth factor (VEGF) dependent modulation in the proliferation, invasion, migration and tube formation of human endothelial umbilical vein cells (HUVECs) in vitro and in vivo in a BALB/c mouse model. Interestingly, the perseverance of the tumor boundary, inhibiting the expression and activity of the matrix metalloproteinase (MMPs) (>5.2-fold) with suppressed degradation of the extracellular matrix paves the way for significant inhibition of metastases. However, an intravenously administered Put-D + O@NCs showed an improved pharmacokinetic profile and exquisite inhibition of the 4T1 induced tumor with a significantly lower toxicity. In a nutshell, these findings highlight the important role of Put in the gp-1 receptor for specific targeting and synergistic delivery of Dox and OA through crystalsomes as a potential approach for the treatment of metastatic breast cancer using combined chemotherapy.

Theranostic lyotropic liquid crystalline nanostructures for selective breast cancer imaging and therapy.

Herein, we report the development of theranostic lyotropic liquid crystalline nanostructures (LCN's) loaded with unique MnO nanoparticles (MNPs) for selective cancer imaging and therapy. MNPs serves as a fluorescent agent as well as a source of manganese (Mn2+) and enables localized oxidative stress under the hallmarks of cancer (acidosis, high H2O2 level). In pursuit of synergistic amplification of Mn2+ antitumor activity, betulinic acid (BA) is loaded in LCN's. In this investigation, nano-architecture of LCN's phase interface is established via SAXS, Cryo-TEM and Cryo-FESEM. Intriguing in vitro studies showed that the LCN's triggered hydroxyl radical production and exhibited greater selective cytotoxicity in cancer cells, ensuring the safety of normal cells. Significant tumor ablation is realized by the 96.5 % of tumor growth inhibition index of LCN's as compared to control group. Key insights into on-site drug release, local anti-cancer response, and tumor location are gained through precise guidance of fluorescent MNPs. In addition, comprehensive assessment of the safety, pharmacokinetics and tumor distribution behavior of LCN's is performed in vivo or ex vivo. This work emphasizes the promise of modulating tumor microenvironment with smart endogenous stimuli sensitive nano systems to achieve advanced comprehensive cancer nano-theranostics without any external stimulus. STATEMENT OF SIGNIFICANCE: Effective diagnosis and treatment approaches with maximum anti-cancer activity and minimal side-effects are critical to ameliorate cancer therapy. Compared to radiation, photodynamic and photothermal therapy, the specific and selective activation of tumor microenvironmental endogenous stimuli for the logical generation of cytotoxic OH· free radicals serves as an efficient therapeutic strategy for chemodynamic-cancer treatment. In this investigation, MnO nanoparticles fulfill two needs (fluorescence-based optical imaging and a source of Mn2+ based chemodynamic therapy) in one unit. This approach also ensures the safety of normal cells, as the toxic OH· free radical activity is substantially suppressed under the mild alkaline/H2O2 conditions in normal cell microenvironment.

Multifunctional hybrid nanoconstructs facilitate intracellular localization of doxorubicin and genistein to enhance apoptotic and anti-angiogenic efficacy in breast adenocarcinoma.

The progressive development of tumors leading to angiogenesis marks the advancement of cancer which requires specific targeted treatment preferably with combination chemotherapy. However, there is still a long way to go to develop an efficient delivery system that could overcome the tumor microenvironment to achieve efficient delivery. Therefore, we have developed spermine (SPM) tethered lipo-polymeric hybrid nanoconstructs with cell surface heparan sulfate proteoglycan (HSPG) specificity for higher intracellular localization and pH dependent charge reversal in the tumor microenvironment (below pH 5.8) to facilitate Doxorubicin (Dox) and Genistein (Gen) release in a synergistic combination. We have observed the specific uptake of SPM anchored hybrid nanoconstructs by receptor-mediated endocytosis in human breast cancer cells (MDA-MB-231) through the HSPG receptor. The SPM-D + G/NPs induced a higher rate of apoptosis in MDA-MB-231 cells via disruption of the mitochondrial membrane potential and also exhibited a stronger anti-angiogenic effect governing the inhibition of VEGF pathway modulation, proliferation, invasion and migration of HUVECs in in vitro and in vivo Balb/c mouse models. The involvement of Akt/Hif1α/VEGF dependent signal cascading and its down-regulation with a pro-apoptotic drug Dox and an anti-angiogenic agent Gen was evident as demonstrated by an in silico docking study and subsequently proven by RT-PCR and western blotting. Altogether this study highlights the potential role of SPM in targeting HSPG receptors and synergistic delivery of Dox and Gen as a promising strategy to effectively inhibit BAC progression and these findings could open a new window to deliver combinations of chemotherapeutic agents along with anti-angiogenic ligands using hybrid nanoparticles.

Targeted co-delivery of the aldose reductase inhibitor epalrestat and chemotherapeutic doxorubicin via a redox-sensitive prodrug approach promotes synergistic tumor suppression.

Rapidly growing evidence suggests a strong dependence of a polyol pathway enzyme Aldose Reductase (AR) in cancer progression and invasion. Thus, inhibiting the AR through therapeutic inhibitors has a potential application in cancer treatment. Epalrestat (EPR) is the only marketed AR inhibitor with proven safety and efficacy in the management of complications like diabetic neuropathy. However, its short half-life and highly hydrophobic nature restrict its use as an anticancer agent. In the present study, we first developed a redox-sensitive prodrug of EPR by conjugating Tocopherol Polyethylene Glycol Succinate (TPGS) which can form a self-assembled micellar prodrug (EPR-SS-TPPGS). Subsequently, to achieve synergistic chemotherapeutic efficacy Doxorubicin (Dox) was co-loaded into the EPR-SS-TPGS micelles where the system is disrupted in a tumor redox environment and co-delivers Dox and EPR in a ratiometric manner. We then employed TPGS conjugated vitamin-B6 as a targeting moiety and prepared the mixed micelles to facilitate VTC receptor-mediated uptake. The encapsulation of Dox and EPR with the developed prodrug approach showed significant synergies with increased intracellular accumulation and redox triggered release in MDA-MB-231 and 4T1 cell lines leading to superior cell cycle arrest, mitochondrial membrane potential, and apoptosis. Prolonged circulation half-life and tumor site bioavailability were achieved for both the drugs with the developed approach. Surprisingly, EPR and Dox combination significantly down-regulated the CD44 receptor expression which is the main contributing factor of tumor metastasis. Furthermore, in vivo evaluation demonstrated a significant reduction in Dox-induced cardiotoxicity. In summary, this nanoencapsulation paradigm of AR inhibitors with chemotherapeutic agents lays the foundation of new opportunities in combination chemotherapy.

Nonlamellar liquid crystals: a new paradigm for the delivery of small molecules and bio-macromolecules.

The aim of this article is to collate the recent developments in the field of drug delivery, medical therapeutics and diagnostics specifically involving the nonlamellar liquid crystalline (NLC) systems. This review highlights different NLC phases having cubic, hexagonal and sponge internal structures, and their application in the field of drug delivery, such as dose reduction, toxicity reduction and therapeutic efficacy enhancement either in the form of nanoparticles, colloidal dispersion or gels. In addition, application of NLC systems as vehicles for peptides, proteins and as a theranostic system in cancer and other disease conditions is also elaborated, which is a growing platform of interest. Overall, the present review gives us a complete outlook on applications of NLC systems in the field of medicine.

Anisamide-Anchored Lyotropic Nano-Liquid Crystalline Particles with AIE Effect: A Smart Optical Beacon for Tumor Imaging and Therapy.

The prospective design of nanocarriers for personalized oncotherapy should be an ensemble of targeting, imaging, and noninvasive therapeutic capabilities. Herein, we report the development of the inverse hexagonal nano-liquid crystalline (NLC) particles that are able to host formononetin (FMN), a phytoestrogen with known anticancer activity, and tetraphenylethene (TPE), an iconic optical beacon with aggregation-induced emission (AIE) signature, simultaneously. Ordered three-dimensional mesoporous internal structure and high-lipid-volume fraction of NLC nanoparticles (NLC NPs) frame the outer compartment for the better settlement of payloads. Embellishment of these nanoparticles by anisamide (AA), a novel sigma receptor targeting ligand using carbodiimide coupling chemistry ensured NLC's as an outstanding vehicle for possible utility in surveillance of tumor location as well as the FMN delivery through active AIE imaging. The size and structural integrity of nanoparticles were evaluated by quasi-elastic light scattering, cryo field emission scanning electron microscopy small-angle X-ray scattering. The existence of AIE effect in the nanoparticles was evidenced through the photophysical studies that advocate the application of NLC NPs in fluorescence-based bioimaging. Moreover, confocal microscopy illustrated the single living cell imaging ability endowed by the NLC NPs. In vitro and in vivo studies supported the enhanced efficacy of targeted nanoparticles (AA-NLC-TF) in comparison to nontargeted nanoparticles (NLC-TF) and free drug. Apparently, this critically designed multimodal NLC NPs may establish a promising platform for targeted and image-guided chemotherapy for breast cancer.

Synchronized Ratiometric Codelivery of Metformin and Topotecan through Engineered Nanocarrier Facilitates In Vivo Synergistic Precision Levels at Tumor Site.

The combination of metabolic modulators with chemotherapy holds vast promise for effective inhibition of tumor progression and invasion. Herein, a ratiometric codelivery platform is developed for metformin (MET), a known metabolic modulator and topotecan (TPT), a chemotherapeutic drug, by engineering lipid bilayer-camouflaged mesoporous silica nanoparticles (LB-MSNs). In an attempt to deliver and maintain high tumor site concentrations of MET and TPT, a novel ion pairing-assisted loading procedure is developed using pamoic acid (PA) as an in situ trapping agent. PA, a hydrophobic counterion, increases the hydrophobicity of MET and TPT and facilitates MSNs with exceptionally high payload capacity (>40 and 32 wt%, respectively) and controlled release profile. Further, the synergy between MET and TPT determined by a modeling approach helps to afford synchronized delivery of both the drugs. Coloaded MET and TPT LB-MSNs present synergistic cytotoxicity against MDA-MB-231/4T1 cells and effectively promote apoptosis via mitochondrial membrane depolarization and cell cycle arrest. Extended pharmacokinetic profiles in preclinical models with fourfold to sevenfold longer circulation half-life and 7.5-100 times higher tumor site concentrations correspond to a significant increase in pharmacodynamic efficacy. Taken together, the developed codelivery approach effectively addresses the challenges in the chemotherapeutic efficacy of MET and TPT collectively.

P-gp modulatory acetyl-11-keto-ß-boswellic acid based nanoemulsified carrier system for augmented oral chemotherapy of docetaxel.

In spite of being a very potent and promising drug against many types of cancer, docetaxel suffers the disadvantage of low solubility and poor bioavailability rendering it unsuitable for oral administration. Also, the available marketed formulation for intravenous administration has its inherent drawbacks owing to the presence of polysorbate 80. Here, we exploited the anticancer and P-gp inhibitory potential of naturally occurring frankincense oil to fabricate a stable docetaxel loaded nanoemulsified carrier system for oral delivery. The nanoemulsion possessing desirable particle size (122±12nm), polydispersity (0.086±0.007) and zeta potential (-29.8±2.1mV) was stable against all type of physical stresses and simulated physiological conditions tested. The formulation showed higher uptake in Caco-2 cells and inhibited P-gp transporter significantly (P<0.05). In MDA-MB-231 cells, it showed less IC50, arrested cells in G2-M phase and exhibited higher degree of apoptosis than marketed formulation Taxotere®. The 182.58±4.16% increment in relative oral bioavailability led to higher in vivo anti-proliferative activity manifesting 19% more inhibition than Taxotere®. Conclusively, it is revealed that the developed nanoemulsion will be a propitious approach towards alternative docetaxel therapy.

Vitamin B6 Tethered Endosomal pH Responsive Lipid Nanoparticles for Triggered Intracellular Release of Doxorubicin.

This study reports the development of Vitamin B6 (VitB6) modified pH sensitive charge reversal nanoparticles for efficient intracellular delivery of Doxorubicin (DOX). Herein, VitB6 was conjugated to stearic acid, and the nanoparticles of the lipid were formulated by solvent injection method (DOX-B6-SA-NP). Because of the pKa (5.6) of VitB6, DOX-B6-SA-NP showed positive charge and enhanced release of DOX at pH 5. Confocal microscopy illustrated that DOX-B6-SA-NP treatment kept higher DOX accumulation inside the cells than conventional pH insensitive lipid nanoparticles (DOX-SA-NP). The cationic charge of nanoparticles subsequently facilitated the endosomal escape and promoted the nuclear accumulation of DOX. Furthermore, in vitro cytotoxicity, apoptosis, cell cycle arrest, and mitochondrial membrane depolarization studies supported the enhanced efficacy of DOX-B6-SA-NP in comparison to free DOX and DOX-SA-NP. Intravenous pharmacokinetics and biodistribution investigations indicated that pH sensitive nanoparticles can significantly prolong the blood circulation time of DOX in biological system and increase the drug accumulation to tumor site. Consequent to this, DOX-B6-SA-NP also exhibited much enhanced therapeutic efficacy and lower toxicity in tumor-bearing rats compared to free DOX. The reduction in toxicity was confirmed by histological and survival analysis. In conclusion, these results suggest that the VitB6 modified charge reversal nanoparticles can be a novel platform for the successful delivery of anticancer drugs.