PolyMetformin combines carrier and anticancer activities for in vivo siRNA delivery

A doxycycline-loaded microfiber of poly-metformin/PCL for eradicating melanoma stem cells

Nowadays, electrospun fibrous mats are used as drug delivery systems for loading of potential drugs in order to kill cancer cells. In the study, a skin patch for treating melanoma cancer after surgery was made using polycaprolactone and polymetformin microfibers that were loaded with doxycycline (PolyMet/PCL@DOX), an anti-cancer stem cell agent. The morphology, structure, mechanical characteristics, swelling, and porosity of the electrospun microfibers were examined. Drug release andanticancereffectiveness of PolyMet/PCL@DOXwas evaluated against A375 melanoma cancer stem cells using the MTS, Flow cytometry, colony formation and CD44 expression assays. Scanning electron microscopy (SEM) verified the micro fibrous structure with a diameter of about 2.31 µm. The porosity and swelling percentages for microfibers was 73.5 % and 2.9 %, respectively. The tensile strength at the breaking point was equal to 3.84 MPa. The IC50 of PolyMet/PCL@DOX was 7.4 μg/mL. The survival rate of A375 cells after 72 h of PolyMet/PCL@DOX treatment was 43.9 %. The colony formation capacity of A375 cells decreased after PolyMet/PCL@DOX treatment. The level of CD44 expression in the PolyMet/PCL@DOX group decreased compared to the control group. Generally, PolyMet/PCL@DOX microfibers can be a promising candidate as a patch after surgery to eradicate cancer stem cells, effectively.

Black Phosphorus Quantum Dot Loaded Bioinspired Nanoplatform Synergized with aPD-L1 for Multimode Cancer Immunotherapy

Efforts to prolong the blood circulation time and bypass immune clearance play vital roles in improving the therapeutic efficacy of nanoparticles (NPs). Herein, a multifunctional nanoplatform (BPP@RTL) that precisely targets tumor cells is fabricated by encapsulating ultrasmall phototherapeutic agent black phosphorus quantum dot (BPQD), chemotherapeutic drug paclitaxel (PTX), and immunomodulator PolyMetformin (PM) in hybrid membrane-camouflaged liposomes. Specifically, the hybrid cell membrane coating derived from the fusion of cancer cell membrane and red blood cell membrane displays excellent tumor targeting efficiency and long blood circulation property due to the innate features of both membranes. After collaboration with aPD-L1-based immune checkpoint blockade therapy, a boosted immunotherapeutic effect is obtained due to elevated dendritic cell maturation and T cell activation. Significantly, laser-irradiated BPP@RTL combined with aPD-L1 effectively eliminates primary tumors and inhibits lung metastasis in 4T1 breast tumor model, offering a promising treatment plan to develop personalized antitumor strategy.

Blood-Brain Barrier-Penetrating and Lesion-Targeting Nanoplatforms Inspired by the Pathophysiological Features for Synergistic Ischemic Stroke Therapy

Ischemic stroke is a dreadful vascular disorder that poses enormous threats to the public health. Due to its complicated pathophysiological features, current treatment options after ischemic stroke attack remains unsatisfactory. Insufficient drug delivery to ischemic lesions impeded by the blood-brain barrier (BBB) largely limits the therapeutic efficacy of most anti-stroke agents. Herein, inspired by the rapid BBB penetrability of 4T1 tumor cells upon their brain metastasis and natural roles of platelet in targeting injured vasculatures, a bio-derived nanojacket is developed by fusing 4T1 tumor cell membrane with platelet membrane, which further clothes on the surface of paeonol and polymetformin-loaded liposome to obtain biomimetic nanoplatforms (PP@PCL) for ischemic stroke treatment. The designed PP@PCL could remarkably alleviate ischemia-reperfusion injury by efficiently targeting ischemic lesion, preventing neuroinflammation, scavenging excess reactive oxygen species (ROS), reprogramming microglia phenotypes, and promoting angiogenesis due to the synergistic therapeutic mechanisms that anchor the pathophysiological characteristics of ischemic stroke. As a result, PP@PCL exerts desirable therapeutic efficacy in injured PC12 neuronal cells and rat model of ischemic stroke, which significantly attenuates neuronal apoptosis, reduces infarct volume, and recovers neurological functions, bringing new insights into exploiting promising treatment strategies for cerebral ischemic stroke management.

Self-Adjuvanting Polyguanidine Nanovaccines for Cancer Immunotherapy

Tapping into the innate immune system's power, nanovaccines can induce tumor-specific immune responses, which is a promising strategy in cancer immunotherapy. However, traditional vaccine design, requiring simultaneous loading of antigens and adjuvants, is complex and poses challenges for mass production. Here, we developed a tumor nanovaccine platform that integrates adjuvant functions into the delivery vehicle, using branched polyguanidine (PolyGu) nanovaccines. These nanovaccines were produced by modifying polyethylenimine (PEI) with various guanidine groups, transforming PEI's cytotoxicity into innate immune activation. The PolyGu nanovaccines based on poly(phenyl biguanidine ) (Poly-PBG) effectively stimulated dendritic cells, promoted their maturation via the TLR4 and NLRP3 pathways, and displayed robust in vivo immune activity. They significantly inhibited tumor growth and extended mouse survival. The PolyGu also showed promise for constructing more potent mRNA-based nanovaccines, offering a platform for personalized cancer vaccine. This work advances cancer immunotherapy toward potential clinical application by introducing a paradigm for developing self-adjuvanting nanovaccines.

Platelet Membrane-Encapsulated Nanocomplexes Based on Profundity Scavenging ROS Strategy for Myocardial Infarction Therapy

Ischemia-induced myocardial injury has become a serious threat to human health, and its treatment remains a challenge. The occurrence of ischemic events leads to a burst release of reactive oxygen species (ROS), which triggers extensive oxidative damage and leads to dysfunctional autophagy, making it difficult for cells to maintain homeostasis. Antioxidants and modulation of autophagy have thus become promising strategies for the treatment of ischemic myocardial injury. This study proposes an antioxidant-activated autophagy therapeutic regimen based on combining melanin (Mel), an excellent antioxidant with metformin mimetic ploymetformin via electrostatic interactions, to obtain a nanocomplex (Met-Mel). The nanocomplex is finally encapsulated with platelet membranes (PMN) to construct a biomimetic nanoparticle (PMN@Met-Mel) capable of targeting injured myocardium. The prepared PMN@Met-Mel has good Mel loading capacity and optimal biosafety. It exhibits excellent antioxidant activity and autophagy activation, rapidly restoring mitochondrial function. Moreover, RNA sequencing (RNA-seq) analysis reveals that PMN@Met-Mel operates mechanistically by triggering the activation of the autophagy pathway. Subsequent in vivo experiments showcase promising cardioprotective effects of these nanoparticles. These discoveries present a newly devised nanoplatform with promising potential for the effective treatment of myocardial infarction.

Chemoimmunotherapeutic Nanogel for Pre- and Postsurgical Treatment of Malignant Melanoma by Reprogramming Tumor-Associated Macrophages

Surgery is the primary method to treat malignant melanoma; however, the residual microtumors that cannot be resected completely often trigger tumor recurrence, causing tumor-related mortality following melanoma resection. Herein, we developed a feasible strategy based on the combinational chemoimmunotherapy by cross-linking carboxymethyl chitosan (CMCS)-originated polymetformin (PolyMetCMCS) with cystamine to prepare stimuli-responsive nanogel (PMNG) owing to the disulfide bond in cystamine that can be cleaved by the massive glutathione (GSH) in tumor sites. Then, chemotherapeutic agent doxorubicin (DOX) was loaded in PMNG, which was followed by a hyaluronic acid coating to improve the overall biocompatibility and targeting ability of the prepared nanogel (D@HPMNG). Notably, PMNG effectively reshaped the tumor immune microenvironment by reprogramming tumor-associated macrophage phenotypes and recruiting intratumoral CD8+ T cells owing to the inherited immunomodulatory capability of metformin. Consequently, D@HPMNG treatment remarkably suppressed melanoma growth and inhibited its recurrence after surgical resection, proposing a promising solution for overcoming lethal melanoma recurrence.

Delivering Relaxin Plasmid by Polymeric Metformin Lipid Nanoparticles for Liver Fibrosis Treatment

BACKGROUND

Liver fibrosis usually progresses to liver cirrhosis and even results in hepatocellular carcinoma, which accounts for one million deaths annually worldwide. To date, anti-liver fibrosis drugs for clinical treatment have not yet been approved. Nowadays, as a natural regulator, Relaxin (RLX) has received increased attention because the expression of RLX could deactivate the activation of hepatic stellate cells (aHSCs) and resolve liver fibrosis. However, its application in treatment is limited due to the short half-life in circulation and low accumulation within the target organ.

METHODS

To address these problems, a kind of polymeric metformin (PolyMet)-loaded relaxin plasmid (pRLX) core-membrane lipid nanoparticle (PolyMet-pRLX-LNPs, PRLNP) was prepared. Here, PolyMet was used as a carrier to replace the traditional polymer polyethylene diene (PEI), which is of higher toxicity, to prolong the circulation time of pRLX in vivo. Then, the antifibrotic ability of PRLNP to overcome liver fibrosis was carried out in C57BL/6 mice. It is worth mentioning that this is the first time to investigate the potential of PRLNP in carbon tetrachloride-induced liver fibrosis.

RESULTS

The results showed that PRLNP effectively downregulated fibrosis-related biomarkers such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Meanwhile, histopathological examinations also showed low collagen accumulation, revealing that PRLNP could histologically and functionally alleviate liver fibrosis. In addition, no significant difference in serum biochemical value between the PRLNP and the normal group, suggesting the safety profile of PRLNP.

CONCLUSION

This research proposed a novel non-toxic treatment method for liver fibrosis with a nanosystem to effectively treat liver fibrosis.

Advances in siRNA delivery approaches in cancer therapy: challenges and opportunities

Advancements in the clinical applications of small interfering RNA (siRNA) in cancer therapy have opened up new possibilities for precision medicine. siRNAs, as powerful genetic tools, have shown potential in targeting and suppressing the expression of specific genes associated with cancer progression. Their effectiveness has been further enhanced by incorporating them into nanoparticles, which protect siRNAs from degradation and enable targeted delivery. However, despite these promising developments, several challenges persist in the clinical translation of siRNA-based cancer therapy. This comprehensive review explores the progress and challenges associated with the clinical applications of siRNA in cancer therapy. This review highlights the use of siRNA-loaded nanoparticles as an effective delivery system for optimizing siRNA efficacy in various types of carcinomas and the potential of siRNA-based therapy as a genetic approach to overcome limitations associated with conventional chemotherapeutic agents, including severe drug toxicities and organ damage. Moreover, it emphasizes on the key challenges, including off-target effects, enzymatic degradation of siRNAs in serum, low tumor localization, stability issues, and rapid clearance from circulation that need to be addressed for successful clinical development of siRNA-based cancer therapy. Despite these challenges, the review identifies significant avenues for advancing siRNA technology from the laboratory to clinical settings. The ongoing progress in siRNA-loaded nanoparticles for cancer treatment demonstrates potential antitumor activities and safety profiles. By understanding the current state of siRNA-based therapy and addressing the existing challenges, we aim to pave the way for translating siRNA technology into effective oncologic clinics as an improved treatment options for cancer patients.

Biguanide-anchored albumin-based nanoplatform inhibits epithelial-mesenchymal transition and reduces the stemness phenotype for metastatic cancer therapy

In clinical chemotherapy, albumin-bound paclitaxel (Abraxane) can improve the tumor targeting property and therapeutic efficacy of paclitaxel (PTX) against orthotopic malignancies. However, patients with metastatic cancer have a poor prognosis, probably due to the instability, chemoresistance, and inability of albumin-bound paclitaxel to alter the tumor microenvironment. Here we propose a new biguanide-modified albumin-based nanoplatform that encapsulates paclitaxel for the effective treatment of metastatic cancer. The PTX is encapsulated in poly (lactic-co-glycolic acid) cores coated with biguanide-modified albumin (HSA-NH). The functionalized nanoparticles (HSA-NH NPs) exhibit a remarkable stable profile with low drug release (P < 0.05 versus Abraxane), target tumor tissues, suppress epithelial-mesenchymal transition (EMT) events for anti-metastatic effects, and reduce the phenotype of cancer stem cells. As a result, HSA-NH NPs effectively prolong animal survival (55 days) by inhibiting not only primary tumor growth but also metastasis. This study provides proof of concept that the biguanide-anchored albumin-based nanoplatform encapsulating PTX is a powerful, safe, and clinically translational strategy for the treatment of metastatic cancer. STATEMENT OF SIGNIFICANCE: Albumin-bound paclitaxel (Abraxane) can increase paclitaxel's tumor targeting and therapeutic efficacy in clinical cancer treatments such as breast cancer. However, the instability, chemoresistance, and lack of tumor microenvironment modulation of albumin-bound paclitaxel may lead to poor therapeutic efficacy in metastatic cancer patients. Here we develop biguanide-anchored albumin-based nanoplatforms that encapsulate paclitaxel (HSA-NH NPs) for metastatic cancer treatment. Poly(lactic-co-glycolic acid) (PLGA) cores encapsulating paclitaxel improve the stability of HSA-NH NPs. Based on the activities of metformin, biguanide-anchored albumin adsorbed on PLGA cores improves paclitaxel efficacy, inhibits various aberrant changes during epithelial-mesenchymal transition, and reduces tumor cell stemness. The biguanide-anchored albumin-based nanoplatform encapsulating PTX can serve as a potent, safe, and clinically translational approach for metastatic cancer therapies.

Extracellular Vesicles-Derived Hybrid Nanoplatforms for Amplified CD47 Blockade-Based Cancer Immunotherapy

Immunomodulation of tumor-associated macrophages (TAMs) into tumor-inhibiting M1-like phenotype is a promising but challenging strategy. Cleverly, tumor cells overexpress CD47, a "don't eat me" signal that ligates with the signal regulatory protein alpha (SIRPα) on macrophages to escape phagocytosis. Thus, effective re-education of TAMs into the "eat me" type and blocking the CD47-SIRPα signaling play pivotal roles in tumor immunotherapy. Herein, it is reported that hybrid nanovesicles (hEL-RS17) derived from extracellular vesicles of M1 macrophages and decorated with RS17 peptide, an antitumor peptide that specifically binds to CD47 on tumor cells and blocks CD47-SIRPα signaling, can actively target tumor cells and remodel TAM phenotypes. Consequently, more M1-like TAMs infiltrate into tumor tissue to phagocytize more tumor cells due to CD47 blockade. By further co-encapsulating chemotherapeutic agent shikonin, photosensitizer IR820, and immunomodulator polymetformin in hEL-RS17, an enhanced antitumor effect is obtained due to the combinational treatment modality and close synergy among each component. Upon laser irradiation, the designed SPI@hEL-RS17 nanoparticles exert potent antitumor efficacy against both 4T1 breast tumor and B16F10 melanoma models, which not only suppresses primary tumor growth but also inhibits lung metastasis and prevents tumor recurrence, exhibiting great potential in boosting CD47 blockade-based antitumor immunotherapy.

Bioactive lipid-nanoparticles with inherent self-therapeutic and anti-angiogenic properties for cancer therapy

Angiogenesis inhibition has become a promising therapeutical strategy for cancer treatment. Current clinical anti-angiogenesis treatment includes antibodies against vascular endothelial growth factor (VEGF) or VEGF receptor, fusion proteins with high affinity to VEGF receptor, and tyrosine kinase inhibitors of VEGF receptor. However, current treatments are prone to systemic toxicity or acquiring drug resistance. A natural bioactive lipid 1,2-dipalmitoyl-sn‑glycero-3-phosphate (dipalmitoyl phosphatidic acid, DPPA) was reported to exhibit anti-angiogenic and anti-tumoral activity. However, the hydrophobic property of DPPA largely restricted its clinical use, while systemic infusion of free DPPA could result in undesirable side effects. Herein, we successfully developed DPPA-based lipid-nanoparticles (DPPA-LNPs) which turns the "therapeutic payload into nanocarrier". This strategy could improve on DPPA's hydrophiliciy, thereby facilitating its systemic administration. . DPPA-LNPs not only retained the therapeutic anti-angiogenic and anti-tumoral bioactivity of parental DPPA, but also greatly improved its tumor targeting ability via enhanced permeability and retention (EPR) effect. This strategy not only eliminates the limitation of drug encapsulation rate, toxicity of the delivery vehicle; but also enhances DPPA bioacvtity in vitro and in vivo. Systemic administration of DPPA-LNPs significantly suppressed the blood vessel formation and tumor growth of triple negative breast cancer and liver cancer growth on both xenograft tumor models. STATEMENT OF SIGNIFICANCE: This is the first-in-kind self-therapeutic inherent lipid to be made into a nanocarrier, with inherent anti-angiogenic and anti-tumor properties. DPPA nanocarrier is fully natural, fully compatible with minimal systemic toxicity. DPPA nanocarrier can accumulate at high concentration at tumor via EPR effect, exerting both anti-angiogenic and anti-tumor effects in vivo. DPPA nanocarrier could be used to encapsulate biologics or small molecules for synergistic anti-cancer therapy.

Relaxin-encapsulated polymeric metformin nanoparticles remodel tumor immune microenvironment by reducing CAFs for efficient triple-negative breast cancer immunotherapy

Cancer-associated fibroblasts (CAFs) are one of the most abundant stromal cells in the tumor microenvironment which mediate desmoplastic response and are the primary driver for an immunosuppressive microenvironment, leading to the failure of triple-negative breast cancer (TNBC) immunotherapy. Therefore, depleting CAFs may enhance the effect of immunotherapy (such as PD-L1 antibody). Relaxin (RLN) has been demonstrated to significantly improve transforming growth factor-β (TGF-β) induced CAFs activation and tumor immunosuppressive microenvironment. However, the short half-life and systemic vasodilation of RLN limit its in vivo efficacy. Here, plasmid encoding relaxin (pRLN) to locally express RLN was delivered with a new positively charged polymer named polymeric metformin (PolyMet), which could increase gene transfer efficiency significantly and have low toxicity that have been certified by our lab before. In order to improve the stability of pRLN in vivo, this complex was further formed lipid poly-γ-glutamic acid (PGA)/PolyMet-pRLN nanoparticle (LPPR). The particle size of LPPR was 205.5 ± 2.9 nm, and the zeta potential was +55.4 ± 1.6 mV. LPPR displayed excellent tumor penetrating efficacy and weaken proliferation of CAFs in 4T1^luc/CAFs tumor spheres in vitro. In vivo, it could reverse aberrantly activated CAFs by decreasing the expression of profibrogenic cytokine and remove the physical barrier to reshape the tumor stromal microenvironment, which enabled a 2.2-fold increase in cytotoxic T cell infiltration within the tumor and a decrease in immunosuppressive cells infiltration. Thus, LPPR was observed retarded tumor growth by itself in the 4T1 tumor bearing-mouse, and the reshaped immune microenvironment further led to facilitate antitumor effect when it combined with PD-L1 antibody (aPD-L1). Altogether, this study presented a novel therapeutic approach against tumor stroma using LPPR to achieve a combination regimen with immune checkpoint blockade therapy against the desmoplastic TNBC model.

Advanced strategies for nucleic acids and small-molecular drugs in combined anticancer therapy

Cancer has been considered as complex malignant consequence of genetic mutations that control the cellular proliferation, differentiation and homeostasis, thus making tumor treatment extremely challenging. To date, a variety of cargo molecules, including nucleic acids drugs (pDNA, miRNA and siRNA), therapeutic drugs (doxorubicin, paclitaxel, daunomycin and gefitinib) and imaging agents (radioisotopes, fluorescence dyes, and MRI contrast agents) have been regarded as the potential medicines in clinical application. However, non-single therapeutic drug could induce the satisfied clinical results because of tumor heterogeneity and multiple drug resistance and the nanotechnology-based combined therapy is becoming an advanced important mode for enhanced anticancer effects. The review gathers the current advanced development to co-deliver small-molecular drugs and nucleic acids for the anticancer therapy with nanomedicine-based combination. Furthermore, the superiority is definitely presented and the barriers are detail discussed to surmount the clinical challenges. In final, future perspectives in rational direction for combined tumor therapy of drugs and nucleic acids are exhibited.

Combined Self-Assembled iRGD Polymersomes for Effective Targeted siRNA Anti-Tumor Therapy

INTRODUCTION

iRGD is usually used as a motif to modify siRNA-nanodelivery vectors to improve tumor-targeting and penetration. However, most of the modifications are realized by covalent conjugation, which normally requires complex preparation processes possibly with low conjugation efficiency and yield, and might lower its bioactivity. To avoid this, here, we presented an alternative physical method to decorate iRGD on nanopolymersomes via facile self-assembly in water.

METHODS

siVEGF was chosen as a siRNA model, and lipopolysaccharide-amine nanopolymersomes (NPs), an efficient cytosolic delivery vector developed by our group, was used as an original vector. By successively incubating siVEGF with NPs, followed by adding iRGD, a siVEGF-loaded NPs functionalized with iRGD (siRNA/iRGD-NPs) was obtained. The properties of iRGD-NPs or siRNA/iRGD-NPs were evaluated in vitro and in vivo.

RESULTS

iRGD is efficiently introduced onto NPs with different amounts, which can be precisely controlled by the feeding ratio. The introduced iRGD keeps tumor-targeting and -penetrating bioactivity, which endows iRGD-NPs with ~100% of tumor-cell uptake and excellent tumor spheroid-penetration, and thus iRGD-NPs can efficiently deliver siVEGF to significantly inhibit angiogenesis in zebrafish and tumor growth in nude mice bearing breast cancer without obvious toxicity.

CONCLUSION

This study provides a facile physical method to decorate nanodelivery vectors with iRGD for effective targeted siRNA anti-tumor therapy.

Current Advancements in Self-assembling Nanocarriers-Based siRNA Delivery for Cancer Therapy

Different therapeutic practices for treating cancers have significantly evolved to compensate and/or overcome the failures in conventional methodologies. The demonstrated potentiality in completely inhibiting the tumors and in preventing cancer relapse has made nucleic acids therapy (NAT)/gene therapy as an attractive practice. This has been made possible because NAT-based cancer treatments are highly focused on the fundamental mechanisms - i.e., silencing the expression of oncogenic genes responsible for producing abnormal proteins (via messenger RNAs (mRNAs)). However, the future clinical translation of NAT is majorly dependent upon the effective delivery of the exogenous nucleic acids (especially RNAs - e.g., short interfering RNAs (siRNAs) - herein called biological drugs). Moreover, nano-based vehicles (i.e., nanocarriers) are involved in delivering them to prevent degradation and undesired bioaccumulation while enhancing the stability of siRNAs. Herein, we have initially discussed about three major types of self-assembling nanocarriers (liposomes, polymeric nanoparticles and exosomes). Later, we have majorly reviewed recent developments in non-targeted/targeted nanocarriers for delivery of biological drugs (individual/dual) to silence the most important genes/mRNAs accountable for inducing protein abnormality. These proteins include polo-like kinase 1 (PLK1), survivin, vascular endothelial growth factor (VEGF), B-cell lymphoma/leukaemia-2 (Bcl-2) and multi-drug resistance (MDR). Besides, the consequent therapeutic effects on cancer growth, invasion and/or metastasis have also been discussed. Finally, we have comprehensively reviewed the improvements achieved in the cutting-edge cancer therapeutics while delivering siRNAs in combination with clinically approved chemotherapeutic drugs.

Lipid nanomaterials-based RNA therapy and cancer treatment

We summarize the most important advances in RNA delivery and nanomedicine. We describe lipid nanoparticle-based RNA therapeutics and the impacts on the development of novel drugs. The fundamental properties of the key RNA members are described. We introduced recent advances in the nanoparticles to deliver RNA to defined targets, with a focus on lipid nanoparticles (LNPs). We review recent advances in biomedical therapy based on RNA drug delivery and state-of-the-art RNA application platforms, including the treatment of different types of cancer. This review presents an overview of current LNPs based RNA therapies in cancer treatment and provides deep insight into the development of future nanomedicines sophisticatedly combining the unparalleled functions of RNA therapeutics and nanotechnology.

Guanylated Hyperbranched Polylysines with High In Vitro and In Vivo Antifungal Activity

With the rapid growth of fungal infections and the emergence of multi-drug resistant (MDR) fungal strains, new antifungals with novel mechanisms are a pressing need to tackle this emerging health problem. Herein it is reported for the first time that hyperbranched polylysine (HPL) shows antifungal activities against Candida, especially for drug-sensitive and MDR C. albicans strains, and broad-spectrum antibacterial activities against both Gram-negative and Gram-positive bacteria. The high antimicrobial activities are ascribed to the high charge density and compact size of the globular structure of HPL. The in vitro antifungal activities of HPL3 are further enhanced by the modification of amine groups to form guanylated polylysines (HPL3-Gxs). Similar to antimicrobial peptides (AMPs), HPLs and HPL3-Gxs interact with and lyse the membranes of microbes, which mitigates the emergence of drug resistance. HPLs and HPL3-Gxs demonstrate excellent in vivo antimicrobial efficacies against both lethal C. albicans challenge in the invasive candidiasis model and lethal Methicillin resistant Staphylococcus aureus challenge in the peritonitis model, and have potentials as broad-spectrum antimicrobials.

Reversing multi-drug resistance by polymeric metformin to enhance antitumor efficacy of chemotherapy

Multi-drug resistance (MDR) in breast cancer poses a great threat to chemotherapy. The expression and function of the ATP binding cassette (ABC) transporter are the major cause of MDR. Herein, a linear polyethylene glycol (PEI) conjugated with dicyandiamide, which called polymeric metformin (PolyMet), was successfully synthesized as a simple and biocompatible polymer of metformin. PolyMet showed the potential to reverse MDR by inhibiting the efflux of the substrate of ATP-binding cassette (ABC) transporter from DOX resistant MCF-7 cells (MCF-7/DOX). To test its MDR reversing effect, PolyMet was combined with DOX to treat mice carrying MCF-7/DOX xenografts. In order to decrease the toxicities of DOX and delivery PolyMet and DOX to tumor at the same time, PolyMet was complexed with poly-γ-glutamic acid-doxorubicin (PGA-DOX) electrostatically at the optimal ratio of 2:3, which were further coated with lipid membrane to form lipid/PolyMet-(PGA-DOX) nanoparticles (LPPD). The particle size of LPPD was 165.8 nm, and the zeta potential was +36.5 mV. LPPD exhibited favorable cytotoxicity and cellular uptake in MCF-7/DOX. Meanwhile, the bioluminescence imaging and immunohistochemical analysis indicated that LPPD effectively conquered DOX-associated MDR by blocking ABC transporters (ABCB1 and ABCC1) via PolyMet. Remarkably, LPPD significantly inhibited the tumor growth and lowered the systemic toxicity in a murine MCF-7/DOX tumor model. This is the first time to reveal that PolyMet can enhance the anti-tumor efficacy of DOX by dampening ABC transporters and activating the AMPK/mTOR pathway, which is a promising strategy for drug-resistant breast cancer therapy.

Blockage of the IDO1 pathway by charge-switchable nanoparticles amplifies immunogenic cell death for enhanced cancer immunotherapy

Immunosuppressive tumor microenvironment (ITM), poor immunogenicity and low tumor penetration markedly reduce the tumor immunotherapy capability. To address these hurdles, we successfully engineered acidity-triggered nanoparticles (NPs) with size-reduction and charge-switchable to boost tumor immunotherapy based on indoleamine 2,3-dioxygenase 1 siRNA (IDO1 siRNA) and immunogenic cell death (ICD). The NPs significantly augmented tumor penetrating ability and improved cellular uptake via the detachment of 2,3-dimethylmaleic anhydride grafted poly(ethylene glycol)-poly(L-lysine) copolymer (mPEG-PLL-DMA, PLM) from large-sized NPs with a negative charge. Subsequently, the NPs with a positive charge and small size rapidly escaped from the lysosomes and released mitoxantrone (MIT) and IDO1 siRNA. The antitumor immune response of IDO1 siRNA and MIT provided good antitumor capability through enhancing DCs maturation, improving numbers of CTLs and downregulating the level of Tregs in tumor tissues. In summary, the results demonstrated that charge-switchable NPs based on blockage of the IDO1 pathway and ICD activation induce an efficient antitumor immune response, thus showing high potential for treating primary/distant tumor and reducing metastasis. STATEMENT OF SIGNIFICANCE: Acidity-triggered nanoparticles (NPs) with size-reduction and charge-switchable to boost tumor immunotherapy based on indoleamine 2,3-dioxygenase 1 siRNA (IDO1 siRNA) and immunogenic cell death (ICD) were engineered. NPs augmented tumor penetrating ability and improved cellular uptake via the detachment of mPEG-PLL-DMA (PLM) from large-sized MIT/siR-PLM/PPA NPs with negative charge to expose miniature and positively charged MIT/siR-PPA NPs. The NPs rapidly escaped from the lysosome and sequentially released mitoxantrone (MIT) and IDO1 siRNA. The antitumor immune synergistic effect of inhibiting the IDO1 pathway by IDO1 siRNA and inducting ICD by MIT provided dramatic antitumor capability through enhancing DCs maturation, improving numbers of CTLs and downregulating the level of Tregs in tumor tissues. And the NPs revealed a promising pathway against aggressive and difficult-to-treat cancers.

Optimization of DOTAP/chol Cationic Lipid Nanoparticles for mRNA, pDNA, and Oligonucleotide Delivery

Lipid nanoparticles (LNPs) can be used as delivery vehicles for nucleic acid biotherapeutics. In fact, LNPs are currently being used in the Pfizer/BioNTech and Moderna COVID-19 vaccines. Cationic LNPs composed of 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)/cholesterol (chol) LNPs have been classified as one of the most efficient gene delivery systems and are being tested in numerous clinical trials. The objective of this study was to examine the effect of the molar ratio of DOTAP/chol, PEGylation, and lipid to mRNA ratio on mRNA transfection, and explore the applications of DOTAP/chol LNPs in pDNA and oligonucleotide transfection. Here we showed that PEGylation significantly decreased mRNA transfection efficiency of DOTAP/chol LNPs. Among non-PEGylated LNP formulations, 1:3 molar ratio of DOTAP/chol in DOTAP/chol LNPs showed the highest mRNA transfection efficiency. Furthermore, the optimal ratio of DOTAP/chol LNPs to mRNA was tested to be 62.5 µM lipid to 1 μg mRNA. More importantly, these mRNA-loaded nanoparticles were stable for 60 days at 4 °C storage without showing reduction in transfection efficacy. We further found that DOTAP/chol LNPs were able to transfect pDNA and oligonucleotides, demonstrating the ability of these LNPs to transport the cargo into the cell nucleus. The influence of various factors in the formulation of DOTAP/chol cationic LNPs is thus described and will help improve drug delivery of nucleic acid-based vaccines and therapies.

Metformin Bicarbonate-Mediated Efficient RNAi for Precise Targeting of TP53 Deficiency in Colon and Rectal Cancers

Colon and rectal cancers are the leading causes of cancer-related deaths in the United States and effective targeted therapies are in need for treating them. Our genomic analyses show hemizygous deletion of TP53, an important tumor suppressor gene, is highly frequent in both cancers, and the 5-year survival of patients with the more prevalent colon cancer is significantly reduced in the patients with the cancer harboring such deletion, although such reduction is not observed for rectal cancer. Unfortunately, direct targeting TP53 has been unsuccessful for cancer therapy. Interestingly, POLR2A, a gene essential for cell survival and proliferation, is almost always deleted together with TP53 in colon and rectal cancers. Therefore, RNA interference (RNAi) with small interfering RNAs (siRNAs) to precisely target/inhibit POLR2A may be an effective strategy for selectively killing cancer cells with TP53 deficiency. However, the difficulty of delivering siRNAs specifically into the cytosol where they perform their function, is a major barrier for siRNA-based therapies. Here, metformin bicarbonate (MetC) is synthesized to develop pH-responsive MetC-nanoparticles with a unique "bomb" for effective cytosolic delivery of POLR2A siRNA, which greatly facilitates its endo/lysosomal escape into the cytosol and augments its therapeutic efficacy of cancer harboring TP53 deficiency. Moreover, the MetC-based nanoparticles without functional siRNA show notable therapeutic effect with no evident toxicity or immunogenicity.

Magnolol-loaded Cholesteryl Biguanide Conjugate Hydrochloride Nanoparticles for Triple-negative Breast Cancer Therapy

The potential of combination therapy using nanoparticle delivery systems in improving triple-negative breast cancer treatment efficacy remains to be explored. Here, we report a novel nanoparticle system using a cholesterol biguanide conjugate hydrochloride (CBH) as both a drug and carrier to load magnolol (MAG). Poly(ethylene glycol)-poly(lactic-co-glycolic acid) (mPEG-PLGA) and aminoethyl anisamide-poly(ethylene glycol)-poly(lactic-co-glycolic acid) (AEAA-PEG-PLGA) were added to form nanoparticles. Nanoparticles accumulated most in tumor tissues when the weight ratio of AEAA-PEG-PLGA to mPEG-PLGA was 4:1. MAG and CBH exerted a synergistic inhibitory effect on 4T1 cells. An in vitro study showed that nanoparticles displayed the highest tumor cell uptake rate, highest apoptosis rate, and strongest inhibitory effect on tumor cell migration and monoclonal formation. CBH might promote nanoparticle uptake by cells and lysosomal escape. After intravenous administration to mice with 4T1 breast tumors in situ, the nanoparticles inhibited tumor growth without obvious toxicity. Western blot results showed that nanoparticles altered the levels of p53, p-AKT, and p-AMPK in the tumor tissue. Moreover, cell apoptosis was found in the same area of H&E-stained and TUNEL-stained tumors treated with the nanoparticles. Collectively, this nanoparticle system provides a novel combination drug delivery strategy for treating triple-negative breast cancer.

Construction of nanocarriers based on nucleic acids and their application in nanobiology delivery systems

In recent years, nanocarriers based on nucleic acids (NCNAs) have emerged as powerful and novel nanocarriers that are able to meet the demand for cancer cell-specific targeting. Functional dynamics analysis revealed good biocompatibility, low toxicity, and programmable structures, and their advantages include controllable size and modifiability. The development of novel hybrids has focused on the distinct roles of biosensing, drug and gene delivery, vaccine transport, photosensitization, counteracting drug resistance and functioning as carriers and logic gates. This review is divided into three parts: (1) DNA nanocarriers, (2) RNA nanocarriers, and (3) DNA/RNA hybrid nanocarriers and their biological applications. We also provide perspectives on possible future directions for growth in this field.

Development, Optimization, and Pharmacokinetics Study of Bufalin/Nintedanib Co-loaded Modified Albumin Sub-microparticles Fabricated by Coaxial Electrostatic Spray Technology

Coaxial electrostatic spray technology has received extensive attention in fabricating micro/nanoparticles for drug delivery. However, there are few reports on applying this technology in preparing albumin nanoparticles. In this study, the bufalin (BF) and nintedanib (NDNB) co-loaded ursodeoxycholic acid and p-biguanides benzoic acid decorated albumin sub-microparticles (BN-DUB subMPs) were fabricated by coaxial electrostatic spray technology and optimized by central composite design. Five percent of albumin (contained 0.7% polyethylene oxide) solution was selected as the shell solution which ejected through outer axis with the flow rate of 0.07 mm/min, while the core solution which contained by BF and NDNB ethanol solution was ejected through inner axis with the flow rate of 0.05 mm/min. In vitro cell studies revealed that the modified albumin possessed good biocompatibility. What's more, the BN-DUB subMPs enhanced the inhibitory effect on the growth of LLC cells efficiently. The pharmacokinetics study showed that the t_1/2 and AUC_0-t of BN-DUB subMPs increased significantly compared with that of the drug solution, which indicated the improved in vivo stability of modified albumin nanoparticles. Thus, this study provided a novel and simple technical platform for the development of albumin-based drug carriers.

A pH-Responsive Nanoplatform Based on Fluorescent Conjugated Polymer Dots for Imaging-Guided Multitherapeutics Delivery and Combination Cancer Therapy

For cancer treatment, nanocarriers were designed with cationic lipids and polymers to improve the cytosolic delivery efficiency of siRNA. Though the positively charged nanocarriers showed great potential for RNA therapy, it was inevitable to generate the potential cytotoxicity. We constructed a pH-responsive nanoplatform, which co-carried siRNA and anticancer drug (hydroxycamptothecine, HCPT), to integrate gene therapy and chemotherapy for combination cancer therapy. The fluorescent conjugated polymer nanoparticles (CPNPs) modified with cell-penetrating peptides were employed as cores to carry siRNA molecules (siRNA-CPNPs) and track the biodistribution of nanotherapeutics by virtue of fluorescence. Calcium phosphate (CaP) nanocoatings were deposited on the surface of siRNA-CPNPs, followed by loading with HCPT and aptamers targeting cancer cells to obtain a targeted and tumor acid-responsive biocompatible nanoplatform. After the uptake of cancer cells, the CaP nanocoatings were decomposed in the acidic endo/lysosomes to release HCPT, and the siRNA-CPNPs were exposed to facilitate the siRNA endo/lysosome escape and cytoplasm delivery. Results obtained from both in vitro and in vivo studies in tumor inhibition expressed that the combined therapy exhibited a better therapeutic efficacy than any monotherapy.

Nanotechnology-Assisted RNA Delivery: From Nucleic Acid Therapeutics to COVID-19 Vaccines

In recent years, the main quest of science has been the pioneering of the groundbreaking biomedical strategies needed for achieving a personalized medicine. Ribonucleic acids (RNAs) are outstanding bioactive macromolecules identified as pivotal actors in regulating a wide range of biochemical pathways. The ability to intimately control the cell fate and tissue activities makes RNA-based drugs the most fascinating family of bioactive agents. However, achieving a widespread application of RNA therapeutics in humans is still a challenging feat, due to both the instability of naked RNA and the presence of biological barriers aimed at hindering the entrance of RNA into cells. Recently, material scientists' enormous efforts have led to the development of various classes of nanostructured carriers customized to overcome these limitations. This work systematically reviews the current advances in developing the next generation of drugs based on nanotechnology-assisted RNA delivery. The features of the most used RNA molecules are presented, together with the development strategies and properties of nanostructured vehicles. Also provided is an in-depth overview of various therapeutic applications of the presented systems, including coronavirus disease vaccines and the newest trends in the field. Lastly, emerging challenges and future perspectives for nanotechnology-mediated RNA therapies are discussed.

Biguanides decorated albumin nanoparticles loading nintedanib for synergic enhanced hepatocellular carcinoma therapy

Nintedanib (ND) was known as a triple tyrosine kinase inhibitors, inhibiting angiogenesis and tissue fibrosis. Biguanide group has attracted much attention for its great penetrating ability to the lipid bilayer of cytomembrane and potential anti-cancer efficacy. In this study, a biguanide group (p-biguanidinobenzoic acid, CBH) decorated bovine serum albumin (CBH-AB) was synthesized as a novel functional biomaterial to prepare the ND loaded CBH-AB nanoparticles (ND-CBH-AB NPs). The results of physical and chemical properties showed that ND-CBH-AB NPs possessed high encapsulation efficiency and drug loading efficiency. In vitro cell study indicated that CBH modification on ND-CBH-AB NPs enhanced the cyctotoxicities to HepG2 cells. Furthermore, pharmacokinetic study showed that ND-CBH-AB NPs had good stability in circulation. Finally, pharmacodynamic studies were conducted, the results indicated that ND-CBH-AB NPs exhibited excellent anti-tumor effect and tumor microenvironment regulation effect. Thereby, this work provides a potential function albumin delivery system for hepatocellular carcinoma therapy.

Liposomes Loaded with Everolimus and Coated with Hyaluronic Acid: A Promising Approach for Lung Fibrosis

Chronic lung allograft dysfunction (CLAD) and interstitial lung disease associated with collagen tissue diseases (CTD-ILD) are two end-stage lung disorders in which different chronic triggers induce activation of myo-/fibroblasts (LFs). Everolimus, an mTOR inhibitor, can be adopted as a potential strategy for CLAD and CTD-ILD, however it exerts important side effects. This study aims to exploit nanomedicine to reduce everolimus side effects encapsulating it inside liposomes targeted against LFs, expressing a high rate of CD44. PEGylated liposomes were modified with high molecular weight hyaluronic acid and loaded with everolimus (PEG-LIP(ev)-HA400kDa). Liposomes were tested by in vitro experiments using LFs derived from broncholveolar lavage (BAL) of patients affected by CLAD and CTD-ILD, and on alveolar macrophages (AM) and lymphocytes isolated, respectively, from BAL and peripheral blood. PEG-LIP-HA400kDa demonstrated to be specific for LFs, but not for CD44-negative cells, and after loading everolimus, PEG-LIP(ev)-HA400kDa were able to arrest cell cycle arrest and to decrease phospho-mTOR level. PEG-LIP(ev)-HA400kDa showed anti-inflammatory effect on immune cells. This study opens the possibility to use everolimus in lung fibrotic diseases, demonstrating that our lipids-based vehicles can vehicle everolimus inside cells exerting the same drug molecular effect, not only in LFs, but also in immune cells.

Co-delivery of IL-12 cytokine gene and cisplatin prodrug by a polymetformin-conjugated nanosystem for lung cancer chemo-gene treatment through chemotherapy sensitization and tumor microenvironment modulation

The combination of chemotherapy and gene therapy has been indicated as a promising approach for cancer therapy. However, this combination strategy is still faced a challenge by the lack of suitable carriers to co-loaded chemotherapeutic drug and gene into one single nanoplatform. In this study, a tumor-targeted HC/pIL-12/polyMET micelleplexes were developed for the co-loading and co-delivery of cisplatin (CDDP) and plasmid encoding interleukin-12 gene (pIL-12), which would be utilized to generate synergistic actions through chemotherapy sensitization and microenvironment modulation. The HC/pIL-12/polyMET exhibited desirable particle size, superior serum stability, effective intracellular CDDP release and pIL-12 transfection efficiency. More important, the HC/pIL-12/polyMET generated the enhanced LLC cell proliferation inhibition and apoptosis induction efficiency. The long-circulating HC/pIL-12/polyMET micelleplexes promoted the accumulation of CDDP and pIL-12 in tumor site, which resulted in significantly inhibiting the growth of lung cancer, and prolonging the overall survival of tumor-bearing mice. The underlying immune mechanism demonstrated the combination of CDDP and pIL-12 activated immune effector cells to release IFN-γ and induced M1-type differentiation of tumor-related macrophages, thereby generating synergistic chemoimmunotherapy effect. Taken together, this study may provide an effective strategy for drug/gene co-delivery and cancer chemoimmunotherapy. STATEMENT OF SIGNIFICANCE: Chemoimmunotherapy has been indicated as an approach to improve efficacy of cancer therapy. Herein, a tumor-targeted micelleplexes (HC/pIL-12/polyMET) were developed for the co-delivery of cisplatin (CDDP) and plasmid encoding IL-12 gene (pIL-12), which can employ the synergistic effects through chemotherapy sensitization and microenvironment modulation. The HC/pIL-12/polyMET exhibited desirable particle size, superior serum stability, high gene transfection efficiency and antitumor activity on tumor cell proliferation inhibition and apoptosis induction. More importantly, the long-circulating HC/pIL-12/polyMET micelleplexes could effectively accumulate in tumor sites and then rapidly release the CDDP and pIL-12, significantly inhibit the growth of lung cancer. This strategy provides a new concept for chemo-gene combination with a strengthened overall therapeutic efficacy of chemoimmunotherapy.

Stimuli-Responsive and Highly Penetrable Nanoparticles as a Multifunctional Nanoplatform for Boosting Nonsmall Cell Lung Cancer siRNA Therapy

In cancer therapy, it is acknowledged that large-size nanoparticles stay in the circulation system for a long time, but their permeability to tumor tissues is poor. To address the conflicting need for prolonging circulation time and favorable tumor tissue penetration ability, a charge conversional multifunctional nanoplatform was strategically designed to improve the efficacy of small interfering RNA (siRNA) therapy against nonsmall cell lung cancer (NSCLC). The development of nanodrug delivery systems (NDDSs) was constructed by loading siRNA on polyamidoamine (PAMAM) dendrimers to build small-sized PAM/siRNA via electrostatic interaction and then capped with a pH-triggered copolymer poly(ethylene glycol) methyl ether (mPEG)-poly-l-lysine (PLL)-2,3-dimethylmaleic anhydride (DMA) (shorted as PLM) under physiological conditions. While in the tumor microenvironment, the acidic reaction of the PLM copolymer changes from negative charge to positive charge due to the cleavable amide bond between mPEG-PLL and DMA, leading to large-size nanoparticles (NPs) with a negative charge that turns into a positive charge and small NPs with a high tumor-penetrating ability. All of the in vitro and in vivo studies validated that PLM/PAM/siRNA NPs possess desirable features including excellent biocompatibility, a prolonged circulation time, significant pH sensitivity, high tumor tissue penetration ability, and sufficient endo-/lysosomal escape. Taken together, all results suggest tremendous potential of the gene therapy based on the stimuli-sensitive PLM/PAM/siRNA NPs, providing a profound application prospective treatment strategy in cancer gene therapy.

Delivery Systems for Nucleic Acids and Proteins: Barriers, Cell Capture Pathways and Nanocarriers

Gene therapy has been used as a potential approach to address the diagnosis and treatment of genetic diseases and inherited disorders. In this line, non-viral systems have been exploited as promising alternatives for delivering therapeutic transgenes and proteins. In this review, we explored how biological barriers are effectively overcome by non-viral systems, usually nanoparticles, to reach an efficient delivery of cargoes. Furthermore, this review contributes to the understanding of several mechanisms of cellular internalization taken by nanoparticles. Because a critical factor for nanoparticles to do this relies on the ability to escape endosomes, researchers have dedicated much effort to address this issue using different nanocarriers. Here, we present an overview of the diversity of nanovehicles explored to reach an efficient and effective delivery of both nucleic acids and proteins. Finally, we introduced recent advances in the development of successful strategies to deliver cargoes.

The use of functionalized nanoparticles to treat Staphylococcus aureus-based surgical-site infections: a systematic review

Staphylococcus aureus-based surgical site infections have become the leading cause of failure for total joint arthroplasty operations and remain a major issue across surgical specialties. Moreover, S. aureus-based infections are becoming drastically more difficult to treat due to the development of antibiotic resistant strains and due to the bacteria's propensity to produce biofilms. The emergence of highly resistant S. aureus infections has created the need for a novel antimicrobial treatment. Functionalized nanoparticles have recently been suggested as being a viable option to fill this void due to their strong antimicrobial and antibiofilm properties. However, said research remains a novel and developing field. The presented systematic review aimed to synthesize the best and most recent evidence available to accurately direct new research towards a viable treatment mechanism. In doing so, the authors performed a comprehensive literature search as directed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The results showed that nanoparticles-particularly those including an iron-oxide component or acidic capping agent-are a viable treatment for S. aureus infections both in vivo and in vitro, and show even greater efficacy when combined with exposure to a magnetic field and irradiation.

Advances in Multiple Stimuli-Responsive Drug-Delivery Systems for Cancer Therapy

Nanomedicines afford unique advantages in therapeutic intervention against tumors. However, conventional nanomedicines have failed to achieve the desired effect against cancers because of the presence of complicated physiological fluids and the tumor microenvironment. Stimuli-responsive drug-delivery systems have emerged as potential tools for advanced treatment of cancers. Versatile nano-carriers co-triggered by multiple stimuli in different levels of organisms (eg, extracorporeal, tumor tissue, cell, subcellular organelles) have aroused widespread interest because they can overcome sequential physiological and pathological barriers to deliver diverse therapeutic “payloads” to the desired targets. Furthermore, multiple stimuli-responsive drug-delivery systems (MSR-DDSs) offer a good platform for co-delivery of agents and reversing multidrug resistance. This review affords a comprehensive overview on the “landscape” of MSR-DDSs against tumors, highlights the design strategies of MSR-DDSs in recent years, discusses the putative advantage of oncotherapy or the obstacles that so far have hindered the clinical translation of MSR-DDSs.

Regulating the immunosuppressive tumor microenvironment to enhance breast cancer immunotherapy using pH-responsive hybrid membrane-coated nanoparticles

The combination of an immuno-metabolic adjuvant and immune checkpoint inhibitors holds great promise for effective suppression of tumor growth and invasion. In this study, a pH-responsive co-delivery platform was developed for metformin (Met), a known immuno-metabolic modulator, and short interfering RNA (siRNA) targeting fibrinogen-like protein 1 mRNA (siFGL1), using a hybrid biomimetic membrane (from macrophages and cancer cells)-camouflaged poly (lactic-co-glycolic acid) nanoparticles. To improve the endo-lysosomal escape of siRNA for effective cytosolic siRNA delivery, a pH-triggered CO₂ gas-generating nanoplatform was developed using the guanidine group of Met. It can react reversibly with CO₂ to form Met-CO₂ for the pH-dependent capture/release of CO₂. The introduction of Met, a conventional anti-diabetic drug, promotes programmed death-ligand 1 (PD-L1) degradation by activating adenosine monophosphate-activated protein kinase, subsequently blocking the inhibitory signals of PD-L1. As a result, siFGL1 delivery by the camouflaged nanoparticles of the hybrid biomimetic membrane can effectively silence the FGL1 gene, promoting T-cell-mediated immune responses and enhancing antitumor immunity. We found that a combination of PD-L1/programmed death 1 signaling blockade and FGL1 gene silencing exhibited high synergistic therapeutic efficacy against breast cancer in vitro and in vivo. Additionally, Met alleviated tumor hypoxia by reducing oxygen consumption and inducing M1-type differentiation of tumor-related macrophages, which improved the tumor immunosuppressive microenvironment. Our results indicate the potential of hybrid biomimetic membrane-camouflaged nanoparticles and combined Met-FGL1 blockade in breast cancer immunotherapy.

Metformin-conjugated micellar system with intratumoral pH responsive de-shielding for co-delivery of doxorubicin and nucleic acid

A novel PMet-P(cdmPEG_2K) polymeric micellar carrier was developed for tumor-targeted co-delivery of DOX and nucleic acids (NA), based on polymetformin and a structure designed to lose the PEG shell in response to the acidic extracellular tumor environment. NA/DOX co-loaded micelleplexes exhibited enhanced inhibition of cell proliferation compared to DOX-loaded micelles, and displayed a higher level of cytotoxicity at an acidic pH (6.8) which mimicks the tumor microenvironment. The PMet-P(cdmPEG_2K) micelles achieved significantly improved transfection with either a reporter plasmid or Cy3-siRNA, and enhanced DOX intracellular uptake in 4T1.2 cells at pH 6.8. Importantly, PMet-P(cdmPEG_2K) micelles showed excellent pEGFP (EGFP expression plasmid) transfection in an aggressive murine breast cancer (4T1.2) model. By using a plasmid encoding IL-12 (pIL-12), we investigated the combined effect of chemotherapy and gene therapy. PMet-P(cdmPEG_2K) micelles co-loaded with DOX and pIL-12 were more effective at inhibiting tumor growth compared to micelles loaded with DOX or pIL-12 alone. In addition, this micellar system was effective in co-delivery of siRNA and DOX into tumor cells. Our results suggest that PMet-P(cdmPEG_2K) has the potential for chemo and nucleic acid combined cancer therapy.

Engineered nanomedicines for tumor vasculature blockade therapy

Tumor vasculature blockade therapy (TVBT), including angiogenesis inhibition, vascular disruption, and vascular infarction, provides a promising treatment modality for solid tumors. However, low selectivity, drug resistance, and possible severe side effects have limited the clinical transformation of TVBT. Engineered nanoparticles offer potential solutions, including prolonged circulation time, targeted transportation, and controlled release of TVBT agents. Moreover, engineered nanomedicines provide a promising combination platform of TVBT with chemotherapy, radiotherapy, photodynamic therapy, photothermal therapy, ultrasound therapy, and gene therapy. In this article, we offer a comprehensive summary of the current progress of engineered nanomedicines for TVBT and also discuss current deficiencies and future directions for TVBT development. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Targeting the Dysfunctional Placenta to Improve Pregnancy Outcomes Based on Lessons Learned in Cancer

In recent decades, our understanding of the disrupted mechanisms that contribute to major obstetrical diseases, including preeclampsia, fetal growth restriction, preterm birth, and gestational diabetes, has increased exponentially. Common to many of these obstetric diseases is placental maldevelopment and dysfunction; the placenta is a significant component of the maternal-fetal interface involved in coordinating, facilitating, and regulating maternal and fetal nutrient, oxygen and waste exchange, and hormone and cytokine production. Despite the advances in our understanding of placental development and function, there are currently no treatments for placental maldevelopment and dysfunction. However, given the transient nature and accessibility from the maternal circulation, the placenta offers a unique opportunity to develop targeted therapeutics for routine obstetric practices. Furthermore, given the similar developmental paradigms between the placenta and cancer, there is an opportunity to appropriate current knowledge from advances in targeted therapeutics in cancer treatments. In this review, we highlight the similarities between early placental development and cancer and introduce a number of targeted therapies currently being explored in cancer and pregnancy. We also propose a number of new effectors currently being targeted in cancer research that have the potential to be targeted in the development of treatments for pregnancy complications. Finally, we describe a method for targeting the placenta using nonviral polymers that are capable of delivering plasmids, small interfering RNA, and other effector nucleic acids, which could ultimately improve fetal and maternal outcomes from complicated pregnancies.

Full-spectrum responsive WO3−x@HA nanotheranostics for NIR-II photoacoustic imaging-guided PTT/PDT/CDT synergistic therapy

A WO_3−x-based nanotheranostic has been successfully fabricated for photoacoustic imaging-guided synergistic tumor targeting therapy in the second near-infrared (NIR-II) biological window.

Small interfering RNA for cancer treatment: overcoming hurdles in delivery

In many ways, cancer cells are different from healthy cells. A lot of tactical nano-based drug delivery systems are based on the difference between cancer and healthy cells. Currently, nanotechnology-based delivery systems are the most promising tool to deliver DNA-based products to cancer cells. This review aims to highlight the latest development in the lipids and polymeric nanocarrier for siRNA delivery to the cancer cells. It also provides the necessary information about siRNA development and its mechanism of action. Overall, this review gives us a clear picture of lipid and polymer-based drug delivery systems, which in the future could form the base to translate the basic siRNA biology into siRNA-based cancer therapies.

Tumor Microenvironment-Triggered Charge Reversal Polymetformin-Based Nanosystem Co-Delivered Doxorubicin and IL-12 Cytokine Gene for Chemo-Gene Combination Therapy on Metastatic Breast Cancer

Cancer metastasis is the leading cause of high mortality and disease recurrence in breast cancer. In this study, a novel tumor microenvironment charge reversal polymetformin (PMet)-based nanosystem co-delivering doxorubicin (DOX) and plasmid encoding IL-12 gene (pIL-12) was developed for chemo-gene combination therapy on metastatic breast cancer. Cationic PMet was readily self-assembled into micelles for DOX physical encapsulation and pIL-12 complexation, and a hyaluronidase-sensitive thiolated hyaluronic acid (HA-SH) was then collaboratively assembled to the pIL-12/DOX-PMet micelleplexes, abbreviated as HA/pIL-12/DOX-PMet. DOX/pIL-12 loaded in HA/pIL-12/DOX-PMet micelleplexes presented prolonged circulation in blood, efficient accumulation in tumors, and internalization in tumor cells via CD44 receptor-mediated tumor specific-targeting, and DOX/pIL-12 was co-released in endo/lysosomes tumor microenvironment followed by HAase-triggered HA-SH deshielding from HA/pIL-12/DOX-PMet micelleplexes. Moreover, HA/PMet micelleplexes displayed excellent pIL-12 transfection and IL-12 expression in tumors of 4T1 tumor-bearing mice. Importantly, HA/pIL-12/DOX-PMet micelleplexes synergistically enhanced the NK cells and tumor infiltrated cytotoxic T lymphocytes and modulated the polarization from protumor M2 macrophages to activated antitumor M1 macrophages, with concomitant decreasing of the immunosuppressive regulatory T (Treg) cells, accompanied by an increase in the cytokines expression of IL-12, IFN-γ and TNF-α, consequently showing an improved antitumor and antimetastasis activity in 4T1 breast cancer lung metastasis mice model. In conclusion, the tumor microenvironment charge reversal HA/PMet nanosystem holds great promise for DOX/pIL-12 co-delivery and exploitation in chemo-gene combination therapy on metastatic breast cancer.

In vivo gene delivery mediated by non-viral vectors for cancer therapy

Gene therapy by expression constructs or down-regulation of certain genes has shown great potential for the treatment of various diseases. The wide clinical application of nucleic acid materials dependents on the development of biocompatible gene carriers. There are enormous various compounds widely investigated to be used as non-viral gene carriers including lipids, polymers, carbon materials, and inorganic structures. In this review, we will discuss the recent discoveries on non-viral gene delivery systems. We will also highlight the in vivo gene delivery mediated by non-viral vectors to treat cancer in different tissue and organs including brain, breast, lung, liver, stomach, and prostate. Finally, we will delineate the state-of-the-art and promising perspective of in vivo gene editing using non-viral nano-vectors.

PolyMet-HA nanocomplexs regulates glucose uptake by inhibiting SHIP2 activity

Metformin, the first-line drug to treat type 2 diabetes, inhibits mitochondrial glycerolphosphate dehydrogenase in the liver to suppress gluconeogenesis. The major adverse effects caused by metformin were lactic acidosis and gastrointestinal discomfort. Therefore, there is need to develop a strategy with excellent permeability and appropriate retention effects.In this study, we synthesized a simple and biocompatible PolyMetformin (denoted as PolyMet) through conjugation of PEI_1.8K with dicyandiamide, and then formed PolyMet-hyaluronic acid (HA) nanocomplexs by electrostatic self-assembly of the polycationic PolyMet and polyanionic hyaluronic acid (HA). Similar to metformin, the PolyMet-HA nanocomplexs could reduce the catalytic activity of the recombinant SHIP2 phosphatase domain in vitro. In SHIP2-overexpressing myotubes, PolyMet-HA nanocomplexes ameliorated glucose uptake by downregulating glucose transporter 4 endocytosis. PolyMet-HA nanocomplexes also could restore Akt signaling and protect the podocyte from apoptosis induced by SHIP2 overexpression. In essence, the PolyMet-HA nanocomplexes act similarly to metformin and increase glucose uptake, and maybe have a potential role in the treatment of type 2 diabetes.

Nanoparticles induce autophagy via mTOR pathway inhibition and reactive oxygen species generation

Due to their unique physicochemical properties, nanoparticles (NPs) have been increasingly developed for use in various fields. However, there has been both growing negative concerns with toxicity and positive realization of opportunities in nanomedicine, coming from the growing understanding of the associations between NPs and the human body, particularly relating to their cellular autophagic effects. This review summarizes NP-induced autophagy via the modulation of the mTOR signaling pathway and other associated signals including AMPK and ERK and also demonstrates how reactive oxygen species generation greatly underlies the regulation processes. The perspectives in this review aim to contribute to NP design, particularly in consideration of nanotoxicity and the potential for the precise application of NPs in nanomedicine.