Nanodrug Inducing Autophagy Inhibition and Mitochondria Dysfunction for Potentiating Tumor Photo-Immunotherapy.

Anticancer immunotherapy is hampered by the poor tumor immunogenicity and immunosuppressive tumor microenvironment (TME). Herein, a liposome nanodrug co-encapsulating doxycycline hydrochloride (Doxy) and chlorin e6 (Ce6) to simultaneously induce autophagy inhibition and mitochondria dysfunction for potentiating tumor photo-immunotherapy is developed. Under near infrared laser irradiation, Ce6 generates cytotoxic reactive oxygen species (ROS) and elicits robust photodynamic therapy (PDT)-induced immunogenic cell death (ICD) for immunosuppressive TME remodeling. In addition, Doxy induced mitochondria dysfunction, which increases ROS generation and enhances PDT to exert more potent killing effect and more powerful ICD. Meanwhile, Doxy increases MHC-I expression on tumor cells surface by efficient autophagy inhibition, leading to more efficient antigen presentation and CTLs recognition to increase tumor immunogenicity. The nanodrugs elicit remarkable antitumor therapy by combining Ce6-mediated PDT and Doxy-induced autophagy inhibition and mitochondria dysfunction. The developed nanodrugs represent a highly efficient strategy for improving cancer immunotherapy.

Rational Design of Bisphosphonate Lipid-like Materials for mRNA Delivery to the Bone Microenvironment.

The development of lipid nanoparticle (LNP) formulations for targeting the bone microenvironment holds significant potential for nucleic acid therapeutic applications including bone regeneration, cancer, and hematopoietic stem cell therapies. However, therapeutic delivery to bone remains a significant challenge due to several biological barriers, such as low blood flow in bone, blood-bone marrow barriers, and low affinity between drugs and bone minerals, which leads to unfavorable therapeutic dosages in the bone microenvironment. Here, we construct a series of bisphosphonate (BP) lipid-like materials possessing a high affinity for bone minerals, as a means to overcome biological barriers to deliver mRNA therapeutics efficiently to the bone microenvironment in vivo. Following in vitro screening of BP lipid-like materials formulated into LNPs, we identified a lead BP-LNP formulation, 490BP-C14, with enhanced mRNA expression and localization in the bone microenvironment of mice in vivo compared to 490-C14 LNPs in the absence of BPs. Moreover, BP-LNPs enhanced mRNA delivery and secretion of therapeutic bone morphogenetic protein-2 from the bone microenvironment upon intravenous administration. These results demonstrate the potential of BP-LNPs for delivery to the bone microenvironment, which could potentially be utilized for a range of mRNA therapeutic applications including regenerative medicine, protein replacement, and gene editing therapies.

Self-Assembly of Stable Nanoscale Platelets from Designed Elastin-like Peptide-Collagen-like Peptide Bioconjugates.

The self-assembly of nanostructures from elastin-like (poly)peptide (ELP) containing block copolymers has been a subject of intense investigation over decades. However, short synthetic ELPs have rarely been used due to their high inverse transition temperature; the use of short ELPs has largely been limited to polymer conjugates. Motivated by our previous work which successfully overcame this barrier by simply conjugating short ELPs with a triple-helix-forming collagen-like peptide, in this study, we further extend the ELP library to a series of ELPs equipped with aromatic residues and having sequences as short as four pentapeptide motifs. The resulting elastin-like peptide-collagen-like peptide (ELP-CLP) bioconjugates unexpectedly self-assembled into nanosized platelets likely by forming a bilayer structure. Given the previously demonstrated ability of many other CLP conjugates to target collagens and the potential for encapsulation of hydrophobic drugs in collapsed ELPs, these ELP-CLP nanoplatelets may offer similar opportunities for targeted delivery in biomedical and other arenas.

Effect of Peptide Sequence on the LCST-Like Transition of Elastin-Like Peptides and Elastin-Like Peptide-Collagen-Like Peptide Conjugates: Simulations and Experiments.

Elastin-like polypeptides (ELPs) are thermoresponsive biopolymers that undergo an LCST-like phase transition in aqueous solutions. The temperature of this LCST-like transition, Tt , can be tuned by varying the number of repeat units in the ELP, sequence and composition of the repeat units, the solution conditions, and via conjugation to other biomacromolecules. In this study, we show how and why the choice of guest (X) residue in the VPGXG pentad repeat tunes the Tt of short ELPs, (VPGXG)4, in the free state and when conjugated to collagen-like peptides (CLPs). In experiments, the (VPGWG)4 chain (in short, WWWW) has a Tt < 278 K, while (VPGFG)4 or FFFF has a Tt > 353 K in both free ELP and ELP-CLP systems. The Tt for the FWWF ELP sequence decreases from being >353 K for free ELP to <278 K for the corresponding ELP-CLP system. The decrease in Tt upon conjugation to CLP has been shown to be due to the crowding of ELP chains that decreases the entropic loss upon ELP aggregation. Even though the net hydrophobicity of ELP has been reasoned to drive the Tt , the origins of lower Tt of WWWW compared to FFFF are unclear, as there is disagreement in hydrophobicity scales in how phenylalanine (F) compares to tryptophan (W). Motivated by these experimental observations, we use a combination of atomistic and coarse-grained (CG) molecular dynamics simulations. Atomistic simulations of free and tethered ELPs show that WWWW are more prone to acquire ß-turn structures than FFFF at lower temperatures. Also, the atomistically informed CG simulations show that the increased local stiffness in W than F due to the bulkier side chain in W compared to F, alone does not cause the shift in the transition of WWWW versus FFFF. The experimentally observed lower Tt of WWWW than FFFF is achieved in CG simulations only when the CG model incorporates both the atomistically informed local stiffness and stronger effective attractions localized at the W position versus the F position. The effective interactions localized at the guest residue in the CG model is guided by our atomistically observed increased propensity for ß-turn structure in WWWW versus FFFF and by past experimental work of Urry et al. quantifying hydrophobic differences through enthalpy of association for W versus F.

Theranostic vesicles based on bovine serum albumin and poly(ethylene glycol)-block-poly(L-lactic-co-glycolic acid) for magnetic resonance imaging and anticancer drug delivery.

Presented in this article is the preparation of a new theranostic vesicle which exhibits excellent in vitro and in vivo T1 magnetic resonance (MR) imaging contrast effect and good anticancer drug delivery ability. The theranostic vesicle has been easily prepared based on an amphiphilic biocompatible and biodegradable dibock copolymer, poly(ethylene glycol)-block-poly(l-lactic-co-glycolic acid) (PEG-b-PLGA) and bovine serum albumin-gadolinium (BSA-Gd) complexes. Dynamic light scattering (DLS), transmission electron microscopy (TEM), UV-vis spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) measurements confirmed the formation and physiological stability of BSA-Gd@PEG-b-PLGA vesicles. Furthermore, the in vitro and in vivo MR imaging experiments revealed their excellent T1-weighted MR imaging function. Red blood cell hemolysis and cytotoxicity experiments confirmed their good blood compatibility and low cytotoxicity. Doxorubicin (DOX) loading and release experiments indicated a more retarded release rate of DOX in those theranostic vesicles than sole PEG-b-PLGA nanoparticles without BSA. Overall, this new biocompatible and biodegradable vesicle shows promising potential in theranostic applications.

Effect of soluble dietary fiber on soy protein isolate emulsion gel properties, stability and delivery of vitamin D3.

Emulsion gels with denser network microstructure and stronger mechanical properties have attracted increasing attentions for delivering lipophilic compounds. In this study, the effect of three distinct soluble dietary fiber (inulin (IN), resistant dextrin (RD) and stachyose (ST)) on the rheological, mechanical and microstructural properties of soy protein isolate (SPI) emulsion gel were firstly investigated. Compared with RD and IN, ST significantly accelerated water holding capacity and thermal stability, which exhibited more compact microstructure and more uniform emulsified oil droplets. Subsequently, the stability and bioavailability of vitamin D3 (VD3) in different delivery systems (medium chain triglycerides (MCT) embedding, SPI-ST emulsion embedding, SPI emulsion gel embedding and SPI-ST emulsion gel embedding) were continue evaluated. In vitro simulated digestion experiment demonstrated that the bioaccessibility of encapsulated VD3 in SPI-ST emulsion gel (69.95 %) was much higher than that of free embedding (48.99 %). In vivo pharmacokinetic experiment revealed that the bioavailability of VD3 was significantly enhanced in SPI-ST gel (p < 0.05), with the AUC0-24h value of 25-OH VD3 (the main circulating form of VD3) were 1.34-fold, 1.23-fold higher than that of free embedding, MCT embedding, respectively. These findings provide a possible approach for the development of high protein/fiber functional foods containing enhanced hydrophobic bioactives.

Small-molecule-mediated control of the anti-tumour activity and off-tumour toxicity of a supramolecular bispecific T cell engager.

The broader clinical use of bispecific T cell engagers for inducing anti-tumour toxicity is hindered by their on-target off-tumour toxicity and the associated neurotoxicity and cytokine-release syndrome. Here we show that the off-tumour toxicity of a supramolecular bispecific T cell engager binding to the T cell co-receptor CD3 and to the human epidermal growth factor receptor 2 on breast tumour cells can be halted by disengaging the T cells from the tumour cells via the infusion of the small-molecule drug amantadine, which disassembles the supramolecular aggregate. In mice bearing human epidermal growth factor receptor 2-expressing tumours and with a human immune system, high intravenous doses of such a 'switchable T cell nanoengager' elicited strong tumour-specific adaptive immune responses that prevented tumour relapse, while the infusion of amantadine restricted off-tumour toxicity, cytokine-release syndrome and neurotoxicity. Supramolecular chemistry may be further leveraged to control the anti-tumour activity and off-tumour toxicity of bispecific antibodies.

The two-year prognosis of multinodular goiter following radiofrequency ablation: based on all nodule burdens.

OBJECTIVE: Few studies used all nodule burdens to specify the prognosis of multinodular goiter (MNG) following radiofrequency ablation (RFA), so this study addresses this question for MNG after completely ablating dominant nodules. METHODS: The RFA indications for MNG included a total of 2-5 benign nodules with over 50% normal tissue on ultrasound, 1-3 well-defined benign dominant nodules on cytology, largest diameter ≥20 mm and/or with clinical complaints, and patient refusal or unable of surgery. A retrospective study of 185 MNG patients with completely ablated dominant nodules in a single-session RFA was conducted. The efficacy and complications were evaluated at 1, 6, 12 months and yearly thereafter. Based on retreatment risks, progressive disease (PD), stable disease (SD) and complete relief (CR) were introduced to assess all nodule load changes. PD was clarified as having new/non-target nodules newly appeared to ACR TI-RADS≥4, or new/enlarged non-target nodules ≥1 cm. RESULTS: The initial ablation ratios of target nodules were 100% at one month. During a mean 22.38±13.75 months (range, 12-60 months), the VRR of ablated nodules was 98.25% at 24 months without regrowth. Cosmetic and symptomatic scores decreased to 1 and 0, respectively, after 48 months. 9.7% of patients (18/185) had PD and the retreatment rate was 2.2% (4/185). The complication rate was 2.7% (5/185). CONCLUSIONS: RFA provides cosmetic and symptomatic relief for an average of two years. RFA is an useful minimally invasive treatment modality for selected MNG patients.

Sono-promoted drug penetration and extracellular matrix modulation potentiate sonodynamic therapy of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) exhibits difficult penetration of most drugs, leading to a very poor therapeutic outcome with a quite low five-year survival rate. The foremost reason is the highly-dense extracellular matrix (ECM) with abundant collagen and fibronectin secreted by the activated pancreatic stellate cells (PSCs). Here, we constructed a sono-responsive polymeric perfluorohexane (PFH) nanodroplet to elicit a deep drug penetration in PDAC via the combination of exogenous ultrasonic (US) exposure and endogenous ECM modulation for potent sonodynamic therapy (SDT) of PDAC. Under US exposure, the rapid drug release and deep penetration in PDAC tissues were realized. The released and well penetrated all-trans retinoic acid (ATRA) as an inhibitor of activated PSCs successfully reduced the secretion of ECM components to form a non-dense matrix conducive to drug diffusion. Meanwhile, the sonosensitizer, manganese porphyrin (MnPpIX), was triggered to produce robust reactive oxygen species (ROS) to exert the SDT effect under US exposure. Furthermore, oxygen (O2) delivered by PFH nanodroplets alleviated tumor hypoxia and enhanced the eradication of cancer cells. Overall, the sono-responsive polymeric PFH nanodroplets were successfully developed as an efficient strategy for PDAC therapy. STATEMENT OF SIGNIFICANCE: Pancreatic ductal adenocarcinoma (PDAC) is a representative refractory cancer with a highly dense extracellular matrix (ECM), making it difficult for most drugs to penetrate the nearly impenetrable desmoplastic stroma. Seeking methods for deep drug penetration is an extremely pressing matter for the treatment of PDAC and many other solid tumors. Herein, we designed a fluoroalkane-modified polymer to prepare a sono-responsive polymeric perfluorohexane (PFH) nanodroplet for loading sonosensitizers, and inhibitors of activated PSCs and O2. Under ultrasonic exposure, the nanodroplet elicited deep drug penetration in PDAC via ultrasonic disturbance and stromal remodeling, inducing potent sonodynamic therapy (SDT) of PDAC. By combining exogenous ultrasonic exposure and endogenous ECM modulation, this work successfully alleviated the severe physiological barrier of PDAC and achieved a favourable treatment effect.

RGD peptide-based lipids for targeted mRNA delivery and gene editing applications.

mRNA therapeutics are promising platforms for protein replacement therapies and gene editing technologies. When delivered via non-viral gene delivery systems, such as lipid nanoparticles (LNPs), mRNA therapeutics are easy to produce and show low toxicity and immunogenicity. However, LNPs show limited delivery efficiency and tissue specificity in certain applications. To overcome this, we designed RGD peptide (Arg-Gly-Asp) based ionizable lipids, which can be formulated into LNPs for integrin binding on cells and targeted mRNA delivery. RGD-LNPs were formulated using microfluidic devices and screened in vitro for size, mRNA encapsulation efficiency, transfection efficiency, and cell viability. A lead candidate, 1A RGD-based hybrid LNP, showed effective mRNA encapsulation and transfection, and was selected for further testing, including the co-delivery of Cas9 mRNA and sgRNA for gene editing applications. In vitro, 1A RGD-based hybrid LNP outperformed a non-targeted control LNP and showed GFP knockout efficiencies up to 90%. Further, the improved cellular uptake was reversed in the presence of soluble RGD, supporting the hypothesis that this improved uptake is RGD-dependent. In vivo, 1A RGD-based hybrid LNPs showed comparable mRNA delivery to the liver and spleen, when compared to a non-targeted control, and had increased expression in the whole body. Overall, this RGD-based hybrid LNP system is a promising platform for targeted mRNA delivery, which may allow for mRNA-based protein replacement and gene editing in a more efficient and specific manner with reduced off-target effects.

Hydroxycholesterol substitution in ionizable lipid nanoparticles for mRNA delivery to T cells.

Delivery of nucleic acids, such as mRNA, to immune cells has become a major focus in the past decade with ionizable lipid nanoparticles (LNPs) emerging as a clinically-validated delivery platform. LNPs-typically composed of ionizable lipids, cholesterol, phospholipids, and polyethylene glycol lipids -have been designed and optimized for a variety of applications including cancer therapies, vaccines, and gene editing. However, LNPs have only recently been investigated for delivery to T cells, which has various therapeutic applications including the engineering of T cell immunotherapies. While several LNP formulations have been evaluated for mRNA delivery, recent work has demonstrated that the utilization of cholesterol analogs may enhance mRNA delivery. Other studies have shown that cholesterols modified with hydroxyl groups can alter endocytic recycling mechanisms. Here, we engineered a library of LNPs incorporating hydroxycholesterols to evaluate their impact on mRNA delivery to T cells by leveraging endosomal trafficking mechanisms. Substitution of 25% and 50% 7α-hydroxycholesterol for cholesterol in LNPs enhanced mRNA delivery to primary human T cells ex vivo by 1.8-fold and 2.0-fold, respectively. Investigation of endosomal trafficking revealed that these modifications also increase late endosome production and reduce the presence of recycling endosomes. These results suggest that hydroxyl modification of cholesterol molecules incorporated into LNP formulations provides a mechanism for improving delivery of nucleic acid cargo to T cells for a range of immunotherapy applications.

Fine structural tuning of the assembly of ECM peptide conjugates via slight sequence modifications.

The self-assembly of nanostructures from conjugates of elastin-like peptides and collagen-like peptides (ELP-CLP) has been studied as means to produce thermoresponsive, collagen-binding drug delivery vehicles. Motivated by our previous work in which ELP-CLP conjugates successfully self-assembled into vesicles and platelet-like nanostructures, here, we extend our library of ELP-CLP bioconjugates to a series of tryptophan/phenylalanine-containing ELPs and GPO-based CLPs [W2F x -b-(GPO) y ] with various domain lengths to determine the impact of these modifications on the thermoresponsiveness and morphology. The lower transition temperature of the conjugates with longer ELP or CLP domains enables the formation of well-defined nanoparticles near physiological temperature. Moreover, the morphological transition from vesicles to platelet-like nanostructures occurred when the ratio of the lengths of ELP/CLP decreased. Given the previously demonstrated ability of many ELP-CLP bioconjugates to bind to both hydrophobic drugs and collagen-containing materials, our results suggest new opportunities for designing specific thermoresponsive nanostructures for targeted biological applications.

Rationally Separating the Corona and Membrane Functions of Polymer Vesicles for Enhanced T2 MRI and Drug Delivery.

It is an important challenge to in situ grow ultrafine super-paramagnetic iron oxide nanoparticles (SPIONs) in drug carriers such as polymer vesicles (also called polymersomes) while keeping their biodegradability for enhanced T2-weighted magnetic resonance imaging (MRI) and drug delivery. Herein, we present a new strategy by rationally separating the corona and membrane functions of polymer vesicles to solve the above problem. We designed a poly(ethylene oxide)-block-poly(ε-caprolactone)-block-poly(acrylic acid) (PEO43-b-PCL98-b-PAA25) triblock copolymer and self-assembled it into polymer vesicle. The PAA chains in the vesicle coronas are responsible for the in situ nanoprecipitation of ultrafine SPIONs, while the vesicle membrane composed of PCL is biodegradable. The SPIONs-decorated vesicle is water-dispersible, biocompatible, and slightly cytotoxic to normal human cells. Dynamic light scattering, transmission electron microscopy, energy disperse spectroscopy, and vibrating sample magnetometer revealed the formation of ultrafine super-paramagnetic Fe3O4 nanoparticles (1.9 ± 0.3 nm) in the coronas of polymer vesicles. Furthermore, the CCK-8 assay revealed low cytotoxicity of vesicles against normal L02 liver cells without and with Fe3O4 nanoparticles. The in vitro and in vivo MRI experiments confirmed the enhanced T2-weighted MRI sensitivity and excellent metastasis in mice. The loading and release experiments of an anticancer drug, doxorubicin hydrochloride (DOX·HCl), indicated that the Fe3O4-decorated magnetic vesicles have potential applications as a nanocarrier for anticancer drug delivery. Moreover, the polymer vesicle is degradable in the presence of enzyme such as Pseudomonas lipases, and the ultrafine Fe3O4 nanoparticles in the vesicle coronas are confirmed to be degradable under weakly acidic conditions. Overall, this decoration-in-vesicle-coronas strategy provides us with a new insight for preparing water-dispersible ultrafine super-paramagnetic Fe3O4 nanoparticles with promising theranostic applications in biomedicine.