Polypeptide Nanoparticles Research Articles

Polypeptide nanoparticles obstruct glucose supply for NIR-II fluorescence-guided tumor starvation and enhanced mild photothermal therapy.

Polypeptide nanoparticles obstruct glucose supply for NIR-II fluorescence-guided tumor starvation and enhanced mild photothermal therapy.

Baicalin-loaded peony seed polypeptide nanoparticles via a pH-driven method: Characterization, release kinetics, and in vitro anti-inflammatory effects.

Baicalin-loaded peony seed polypeptide nanoparticles via a pH-driven method: Characterization, release kinetics, and in vitro anti-inflammatory effects.

ROPISA Strategy for In-Situ Loading in Polypeptide Nanoparticles.

We report a ring-opening polymerization induced self-assembly (ROPISA) synthetic strategy for in-situ encapsulation of fluorescent dye molecules in poly(ʟ-serine) based polypeptide nano-assemblies and demonstrate their cellular bioimaging application. A bulky ʟ-serine N-carboxyanhydride monomer is tailor-made and polymerized using PEG-amine as hydrophilic macroinitiator in water at pH 8.5 to obtain polypeptide block copolymer as stable dispersions in the form of opalescent solutions. Both water soluble fluorescent dyes like Rhodamine B, HPTS and water insoluble fluorescent dye like Nile red are readily encapsulated in-situ in the ROPISA process which afforded stable fluorescent polypeptide nanoformulation for direct application in biological system. The polypeptide nanoparticle dispersion is found to be stable, and they are found to have spherical nanoparticle morphology of 25nm in size. Both the nascent and fluorescent dye encapsulated polypeptide nanoparticles were found to be nontoxic to mammalian cells up to 100µg/mL and non-hemolytic to Red Blood Cells. These polypeptide nanoparticles were readily endocytosed across the cell membrane and internalized in the cytosol, and the proof-of-concept was established by confocal microscopy. This newly developed in-situ ROPISA process for fluorescent dye loading opens up new platform for polypeptide nano-formulations for application in both material and biomedical fields.

In Situ Formation of Nanoparticles from Graft Copolypeptides Under Dispersion Polymerization Conditions.

A simple method is presented for preparing polypeptide nanoparticles using hydrophilic biosynthetic ε-poly(lysine) (εPL) as a reactive surfactant under dispersion polymerization conditions. In situ graft polymerization of benzyl-L-glutamic acid N-carboxyanhydride (BLG-NCA) triggers the self-assembly of amphiphilic copolymers into nanoparticles, which are colloidally stabilized by the remaining εPL amino groups at the particle surface. The average nanoparticle diameter can be controlled in the range of 40-120nm by varying the initiator-to-NCA ratio, as demonstrated by the correlation between graft copolymer molecular weight (measured by size exclusion chromatography) and the z-average diameter (measured by dynamic light scattering). Secondary structure analysis indicates that the α-helical conformation of poly(benzyl-L-glutamate) (PBLG) grafts plays a role in both accelerating NCA polymerization and stabilizing the nanostructures. This approach is readily scalable to high concentrations and offers a straightforward route to peptidomimetic nanoparticles, entirely composed of amino acids, with promising potential for nanomedicine applications.

Alanine and glutathione targeting of dopamine- or ibuprofen-coupled polypeptide nanocarriers increases both crossing and protective effects on a blood–brain barrier model

BackgroundTargeting the blood–brain barrier (BBB) is a key step for effective brain delivery of nanocarriers. We have previously discovered that combinations of BBB nutrient transporter ligands alanine and glutathione (A-GSH), increase the permeability of vesicular and polypeptide nanocarriers containing model cargo across the BBB. Our aim was to investigate dopamine- and ibuprofen-coupled 3-armed poly(l-glutamic acid) nanocarriers targeted by A-GSH for transfer across a novel human co-culture model with induced BBB properties. In addition, the protective effect of ibuprofen containing nanoparticles on cytokine-induced barrier damage was also measured.MethodDrug-coupled nanocarriers were synthetized and characterized by dynamic light scattering and transmission electron microscopy. Cellular effects, uptake, and permeability of the nanoparticles were investigated on a human stem cell-based co-culture BBB model with improved barrier properties induced by a small molecular cocktail. The model was characterized by immunocytochemistry and permeability for marker molecules. Nanocarrier uptake in human brain endothelial cells and midbrain organoids was quantified by spectrofluorometry and visualized by confocal microscopy. The mechanisms of cellular uptake were explored by addition of free targeting ligands, endocytic and metabolic inhibitors, co-localization of nanocarriers with intracellular organs, and surface charge modification of cells. The protective effect of ibuprofen-coupled nanocarriers was investigated against cytokine-induced barrier damage by impedance and permeability measurements.ResultsTargeted nanoformulations of both drugs showed elevated cellular uptake in a time-dependent, active manner via endocytic mechanisms. Addition of free ligands inhibited the cellular internalization of targeted nanocarriers suggesting the crucial role of ligands in the uptake process. A higher permeability across the BBB model was measured for targeted nanocarriers. After crossing the BBB, targeted dopamine nanocarriers subsequently entered midbrain-like organoids derived from healthy and Parkinson’s disease patient-specific stem cells. The ibuprofen-coupled targeted nanocarriers showed protective effects against cytokine-induced barrier damage.ConclusionBBB-targeted polypeptide nanoparticles coupled to therapeutic molecules were effectively taken up by brain organoids or showing a BBB protective effect indicating potential applications in nervous system pathologies.Graphical

A Novel Injectable Polypeptide Nanoparticle Encapsulated siRNA Targeting TGF-β1 and COX-2 for Localized Fat Reduction II: Phase I Clinical Trial.

Rising demand for non-invasive body contouring is driven by aesthetics and the obesity epidemic. Deoxycholic acid (DCA) is the only FDA-approved injectable for fat reduction but can cause side effects and significant local skin reactions (LSR). RNA interference, using small interfering RNA (siRNA) molecules, offers targeted fat reduction by silencing genes involved in fat maintenance. STP705, a siRNA injectable targeting TGF-β1 and COX-2, has shown promising preclinical results both invitro and in animal models. To evaluate the safety and tolerability of STP705 for localized fat reduction in subjects undergoing abdominoplasty. This phase I dose-ranging, randomized, vehicle-controlled trial involved eight females undergoing abdominoplasty who received subcutaneous STP705 injections at varying concentrations and volumes in designated abdominal zones. Safety assessments, including physical exams, lab tests, ECGs, and local skin reactions (LSRs), were conducted at baseline and follow-ups. Histopathologic evaluations of biopsies collected during abdominoplasty assessed adipocyte apoptosis and tissue remodeling. STP705 demonstrated a favorable safety profile with no clinically significant changes in lab values, vital signs, or ECGs. Adverse events (AEs) were rare and transient. The incidence, intensity, and duration of LSRs were low throughout the study. Histological analysis revealed adipocyte destruction, fat remodeling, and necrosis. STP705 was safe and very well-tolerated and showed preliminary efficacy in inducing adipocyte apoptosis and tissue remodeling, suggesting a safer alternative or adjunct to existing fat reduction therapies. These findings support further trials to establish the safety and efficacy of STP705 for targeted fat reduction and body contouring. ClinicalTrials.gov identifier: NCT05422378.

Novel Approach to Fat Reduction: A Phase I Study Evaluating Safety and Tolerability of STP705 in Abdominoplasty

Background: RNAi therapeutics are a rapidly developing technology with broad medical applications predicated on reducing the expression of genes with key links to disease pathogenesis. The TGF-β1/Smad3 and COX-2 signaling pathways are strongly implicated in obesity and type 2 diabetes. Reducing the expression of TGF-β1 and COX-2 may have benefits in fat reduction procedures. The aim of this study was to assess the safety and tolerability of STP705 (a TGF-β1/COX-2 siRNA complex in a polypeptide nanoparticle vehicle) injections in persons undergoing abdominoplasty. A secondary aim was to make initial histologic observations on the efficacy of STP705 injections in inducing adipocyte apoptosis for the purpose of focal fat reduction. Methods: The study treatment consisted of 3 rounds of treatment with 7 subcutaneous abdominal injections of STP705 or placebo. Eight female subjects aged 18-65 years received 120 μg, 240 μg, or 360 μg STP705 in 0.5 or 1.0 ml doses (per injection) or an equivalent amount of placebo injected randomly across seven 1 cm2 areas. Treatments were administered 28 days apart with follow-ups occurring at 2 and 7 days’ post-procedure. Tissue samples from each of the 7 injection sites were harvested from total abdominoplasty excisional specimens obtained 28 days after the final injection. Safety assessments were conducted, including physical examination, clinical laboratory tests, electrocardiograms, evaluation of local skin reactions (LSRs), and collection of adverse events (AEs). Lipolytic and inflammatory effects of STP705 were assessed by blinded histologic analysis of harvested tissue samples. Results: There were no clinically significant changes in clinical labs, vital signs, or ECGs. The incidence of LSRs was low throughout the study. There were 3 moderate AEs deemed likely to be related to STP705 injection; none required intervention, and all resolved without dose modification. Histology revealed marginally dose-dependent tissue response with adipocyte destruction and fat remodeling. Conclusion: In general, STP705 was well tolerated at all concentrations and volumes studied. STP705 demonstrated excellent safety, and initial histologic analysis is suggestive of its efficacy in adipocyte destruction. The lack of cutaneous side effects with STP705 injection is an advantage over current treatments for similar indications.

Diradicaloid-Loaded Polypeptide Nanoparticles for Two-Photon NIR Phototheranostics.

Stable organic radicals, with unique electronic transitions from the ground state (D0) to the doublet excited state (D1), show promise as high-fluorescence quantum yield dyes. While organic small-molecule photosensitizers (PSs) have advanced for tumor photodynamic therapy (PDT), opportunities exist to enhance their performance and functionality. Herein, we synthesized Thiele's fluorocarbon derivative diradicaloid TFC-I with nearly 100% PLQY and integrated it into amphiphilic polypeptide nanoparticles, P-TI, using a precursor-doping approach. P-TI demonstrated notable features including high photostability, aggregation-induced emission, bright near-infrared fluorescence, substantial quantum yield (37% PLQY), robust near-infrared two-photon absorption (∼400 GM cross section), and superior ROS generation compared to commercial PSs. In vitro and in vivo experiments confirmed that P-TI performed well in mitochondria-targeted PDT, two-photon fluorescence imaging, and biosafety. This work highlights the use of organic stable radicals with precursor-doping for efficient PDT and deep tumor tissue imaging.

Tumor microenvironment-activated polypeptide nanoparticles for oncolytic immunotherapy

Tumor microenvironment-activated polypeptide nanoparticles for oncolytic immunotherapy

Novel injectable polypeptide nanoparticle encapsulated siRNA targeting TGF-β1 and COX-2 for localized fat reduction I: Preclinical invitro and animal models.

Obesity and localized fat accumulation continue to drive the demand for minimally invasive body contouring technologies including injectable compounds for local fat reduction. siRNA offers a potential for an injectable to specifically target and silence genes involved in adipogenesis with minimal inflammatory side effects. This study evaluates the efficacy of STP705, an injectable containing siRNA encapsulated within histidine-lysine polypeptide (HKP) nanoparticles targeting transforming growth factor β1 (TGF-β1) and cyclooxygenase-2 (COX-2), crucial mediators in adipocyte differentiation and fat retention, using invitro, porcine, and murine models. In vitro experiments on mouse preadipocytes and invivo trials using Diet Induced Obese (DIO) mice and Yucatan minipigs were conducted to assess the gene silencing efficiency, tissue localization, pharmacodynamics, and safety profile of STP705. STP705 effectively reduced the expression of TGF-β1 and COX-2, with a notable decrease in adipocyte volume and lipid content without adverse systemic effects. In DIO mice, the HKP-siRNA complex demonstrated precise localization to injected adipose tissue, maintaining significant gene silencing, and detectable levels of siRNA for up to 14 days post-administration. Similar results in minipigs showed a significant reduction in subcutaneous adipose tissue thickness. The results of these studies support the use of targeted siRNA therapy specifically targeting TGF-β1 and COX-2, for localized fat reduction, offering a potential minimally invasive alternative to current fat reduction methods.

Synthesis of D-A-type groups modified aza-BODIPY fluorescent dye encapsulated by amphiphilic polypeptide nanoparticles for NIR-II phototheranostics

Synthesis of D-A-type groups modified aza-BODIPY fluorescent dye encapsulated by amphiphilic polypeptide nanoparticles for NIR-II phototheranostics

Polypeptide nanoparticles conjugated with an NIR-II organic dye for TRPV1 channel blockade enhance mild phototheranostics

Polypeptide nanoparticles conjugated with an NIR-II organic dye for TRPV1 channel blockade enhance mild phototheranostics

ATP Inhibition for Starvation/Mild Photothermal/Photodynamic Synergy Therapy Using Polypeptide Nanoparticles Conjugating 2-Deoxy-D-Glucose and Dye under NIR Phototheranostic Strategy.

Rapid propagation of tumor cells requires plenty of energy, which is adenosine triphosphate (ATP) dependent. ATP inhibition in tumors not only results in the starvation of tumor cells but also down-regulation of the level of heat shock proteins (HSPs), which usually increase during traditional photothermal therapy (PTT), especially when the temperature is up 50°C. 2-deoxy-D-glucose (2DG) is an anti-glycolytic reagent and can be used as an efficient agent for ATP inhibition in tumors. Compared with typical PTT, low-temperature mild photothermal therapy (MPTT) is receiving more and more attention because it avoids the high temperatures causing damage to the normal tissue, and the increase of HSPs which decrease PTT. Here, multifunctional polypeptide nanoparticles pDG@Ahx conjugating both a NIR probe Ahx-BDP and 2DG into the side chain of the amphiphilic polypeptide have been prepared. In vitro and in vivo studies reveal that the as-prepared nanoparticles achieve a synergistic effect of starvation/MPTT/PDT (photodynamic therapy), and it provides a new strategy to NIR-I/II fluorescence imaging-guided starvation/MPTT/PDT synergy therapy for tumors.

Self-enhanced regulation of stable organic radicals with polypeptide nanoparticles for mild second near-infrared phototheranostics

Self-enhanced regulation of stable organic radicals with polypeptide nanoparticles for mild second near-infrared phototheranostics

Optimization of Dendritic Polypeptide Delivery System for Antisense Antibacterial Agents Targeting ftsZ.

There is an urgent requirement for a novel treatment strategy for drug-resistant Staphylococcus aureus (S. aureus) infection. Antisense antimicrobials are promising antimicrobials, and efficient drug delivery systems are necessary for the further development of antisense antimicrobials. To develop new antisense drugs and further improve delivery efficiency and safety, we designed and screened new antisense sequences and optimized dendritic polypeptide nanoparticles (DP-AD) discovered in previous studies. The N/P ratio is optimized from 8:1 to 6:1, and the positive charge number of the optimized DP-AD is studied comprehensively. The results show that the N/P ratio and positive charge number have no significant effect on the particle size distribution and transport efficiency of DP-AD. Reducing the N/P ratio can significantly reduce the cytotoxicity of DP-AD, but it does not affect its delivery efficiency and antibacterial activity. However, in drug-resistant strains, the antibacterial activity of DP-AD76:1 with 10 positive charges is higher than that of DP-AD86:1 with 8 positive charges. Our research discovered a novel ASOs targeting ftsZ and concluded that DP-AD76:1 with 10 positive charges was the optimal choice at the current stage, which provided a promising strategy for the treatment of drug-resistant S. aureus.

Codelivery of TGFβ and Cox2 siRNA inhibits HCC by promoting T-cell penetration into the tumor and improves response to Immune Checkpoint Inhibitors.

Upregulation of TGFβ and Cox2 in the tumor microenvironment results in blockade of T-cell penetration into the tumor. Without access to tumor antigens, the T-cell response will not benefit from administration of the immune checkpoint antibodies. We created an intravenous polypeptide nanoparticle that can deliver two siRNAs (silencing TGFβ and Cox2). Systemic administration in mice, bearing a syngeneic orthotopic hepatocellular carcinoma (HCC), delivers the siRNAs to various cells in the liver, and significantly reduces the tumor. At 2mg/kg (BIW) the nanoparticle demonstrated a single agent action and induced tumor growth inhibition to undetectable levels after five doses. Reducing the siRNAs to 1mg/kg BIW demonstrated greater inhibition in the presence of PD-L1 mAbs. After only three doses BIW, we could still recover a smaller tumor and, in tumor sections, showed an increase in penetration of CD4+and CD8+T-cells deeper into the remaining tumor that was not evident in animals treated with non-silencing siRNA. The combination of TGFβ and Cox2 siRNA co-administered in a polypeptide nanoparticle can act as a novel therapeutic alone against HCC and may augment the activity of the immune checkpoint antibodies. Silencing TGFβ and Cox2 converts an immune excluded (cold) tumor into a T-cell inflamed (hot) tumor.

Doxorubicin delivery systems based on polypeptide nanoparticles for subcutaneous administration in cancer therapy

Doxorubicin delivery systems based on polypeptide nanoparticles for subcutaneous administration in cancer therapy

Fabrication of Oleophilic Polypeptide Nanoparticle from Complexing of Cross-Linked Epsilon-poly-l-lysine with Docusate Sodium for Preparation of Bactericidal Thermoplastic Polyurethanes.

Thermoplastic polyurethanes (TPUs) are extensively utilized in the biomedical field due to their exceptional mechanical properties and biocompatibility. However, the lack of antibacterial activity limits their application ranges. Nanoscopic particle-based additives with inherent antibacterial characteristics are regarded as promising strategies to prevent biomaterials-associated infection. Herein, a novel polymeric nanoparticle is prepared, which integrates chemically cross-linked epsilon-poly-l-lysine (CPL) and anionic surfactant-docusate sodium (DS). The cross-linked epsilon-poly-l-lysine/docusate sodium (CPL/DS) nanoparticle can be well dispersed in organic solvent and a polymer matrix, which is beneficial to endowing TPUs with synergistic miscibility and antibacterial properties. An antibacterial test showed that the CPL/DS nanoparticles have strong antibacterial activity against S. aureus. Moreover, the results of antibacterial experiments in vitro revealed that almost 100% of S. aureus could be killed by CPL/DS nanoparticle-embedded TPU film with a content of 0.5 wt %. In addition, all of the CPL/DS modified TPU films showed good cytocompatibility in vitro. Consequently, this kind of CPL/DS nanoplatform has great potential to serve as a safe and high-efficient bactericidal agent for endowing biomedical devices with bactericidal property.

Disease-specific corona mediated co-delivery of MTX and siRNA-TNFα by a polypeptide nanoplatform with antigen-scavenging functions in psoriasis

Disease-specific corona mediated co-delivery of MTX and siRNA-TNFα by a polypeptide nanoplatform with antigen-scavenging functions in psoriasis

Carfilzomib-Loaded Ternary Polypeptide Nanoparticles Stabilized by Polycationic Complexation

Carfilzomib-Loaded Ternary Polypeptide Nanoparticles Stabilized by Polycationic Complexation