New strategies to self-assemble biocompatible materials into nanoscale, drug-loaded packages with improved therapeutic efficacy are needed for nanomedicine. To address this need, we developed ...artificial recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into sub-100-nm-sized, near-monodisperse nanoparticles on conjugation of diverse hydrophobic molecules, including chemotherapeutics. These CPs consist of a biodegradable polypeptide that is attached to a short Cys-rich segment. Covalent modification of the Cys residues with a structurally diverse set of hydrophobic small molecules, including chemotherapeutics, leads to spontaneous formation of nanoparticles over a range of CP compositions and molecular weights. When used to deliver chemotherapeutics to a murine cancer model, CP nanoparticles have a fourfold higher maximum tolerated dose than free drug, and induce nearly complete tumour regression after a single dose. This simple strategy can promote co-assembly of drugs, imaging agents and targeting moieties into multifunctional nanomedicines.
Previous studies on the influence of weather on Aedes aegypti dynamics in Puerto Rico suggested that rainfall was a significant driver of immature mosquito populations and dengue incidence, but ...mostly in the drier areas of the island. We conducted a longitudinal study of Ae. aegypti in two neighborhoods of the metropolitan area of San Juan city, Puerto Rico where rainfall is more uniformly distributed throughout the year. We assessed the impacts of rainfall, temperature, and human activities on the temporal dynamics of adult Ae. aegypti and oviposition. Changes in adult mosquitoes were monitored with BG-Sentinel traps and oviposition activity with CDC enhanced ovitraps. Pupal surveys were conducted during the drier and wetter parts of the year in both neighborhoods to determine the contribution of humans and rains to mosquito production. Mosquito dynamics in each neighborhood was compared with dengue incidence in their respective municipalities during the study. Our results showed that: 1. Most pupae were produced in containers managed by people, which explains the prevalence of adult mosquitoes at times when rainfall was scant; 2. Water meters were documented for the first time as productive habitats for Ae. aegypti; 3. Even though Puerto Rico has a reliable supply of tap water and an active tire recycling program, water storage containers and discarded tires were important mosquito producers; 4. Peaks in mosquito density preceded maximum dengue incidence; and 5. Ae. aegypti dynamics were driven by weather and human activity and oviposition was significantly correlated with dengue incidence.
Nanoparticle technologies are significantly impacting the development of both therapeutic and diagnostic agents. At the intersection between treatment and diagnosis, interest has grown in combining ...both paradigms into clinically effective formulations. This concept, recently coined as theranostics, is highly relevant to agents that target molecular biomarkers of disease and is expected to contribute to personalized medicine. Here we review state-of-the-art nanoparticles from a therapeutic and a diagnostic perspective and discuss challenges in bringing these fields together. Major classes of nanoparticles include, drug conjugates and complexes, dendrimers, vesicles, micelles, core–shell particles, microbubbles, and carbon nanotubes. Most of these formulations have been described as carriers of either drugs or contrast agents. To observe these formulations and their interactions with disease, a variety of contrast agents have been used, including optically active small molecules, metals and metal oxides, ultrasonic contrast agents, and radionuclides. The opportunity to rapidly assess and adjust treatment to the needs of the individual offers potential advantages that will spur the development of theranostic agents.
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•Protein and/or polypeptide therapeutics have emerged to address multiple ocular conditions.•Understanding and overcoming the physiological and anatomical ...challenges in ocular tissue remains essential to develop successful treatments.•Structural engineering of protein/ peptide platforms can substantially enhance their targeted delivery and retention.•Selection of method of administration is a critical determinant for therapeutic delivery.
Hybrid or recombinant protein-polymers, peptide-based biomaterials, and antibody-targeted therapeutics are widely explored for various ocular conditions and vision correction. They have been noted for their potential biocompatibility, potency, adaptability, and opportunities for sustained drug delivery. Unique to peptide and protein therapeutics, their production by cellular translation allows their precise modification through genetic engineering. To a greater extent than drug delivery to other systems, delivery to the eye can benefit from the combination of locally-targeted administration and protein-based specificity. Consequently, a range of delivery platforms and administration methods have been exploited to address the ocular delivery of peptide and protein biomaterials. This review discusses a sample of preclinical and clinical opportunities for peptide-based drug delivery to the eye.
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•Elastin-like polypeptides (ELP) can be genetically-fused or chemically-bioconjugated to therapeutic agents.•ELP shielding sterically stabilizes the surface of nanoparticles, ...promoting their colloidal stability.•Even in nanoparticulate assemblies, fusion ELPs conserve bioactivity of their therapeutic cargo and extend their pharmacokinetic half-life.
Elastin-like polypeptides (ELP) are versatile, thermo-responsive polymers that can be conjugated to virtually any therapeutic cargo. Derived from short amino-acid sequences and abundant in humans, certain ELPs display low immunogenicity. Substrates for endogenous proteases, ELPs are biodegradable and thus, are candidate biomaterials. Peptides and proteins can be directly coupled with ELPs through genetic engineering, while other polymers and small molecules can be appended through covalent bioconjugation or non-covalent complexation. ELPs that phase separate at physiological temperatures can form the core of nano assemblies; however, ELPs that remain soluble can sterically stabilize the corona of a variety of nanoparticles. Nanoparticles with ELPs at their corona promote colloids with favorable pharmacokinetic (PK) properties that enables therapeutic efficacy with intermittent administration. This review highlights a comprehensive spectrum of ELP fusions shown to stabilize the solubility, and sometimes bioactivity, of their cargo – with a focus on biophysical properties that underlie their therapeutic effects.
COVID-19 is an infectious respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This virus contains a crucial coat protein that engages with target cells via ...a receptor binding domain (RBD) on its spike protein. To better study the RBD and its therapeutic opportunities, we genetically engineered a simple fusion with a thermo-responsive elastin-like polypeptide (ELP). These fusions express in Escherichia coli at a high yield in the soluble fraction and were easily purified using ELP-mediated phase separation (79 mg/L culture). Interestingly, they assembled peptide-based nanoparticles (R h = 71.4 nm), which was attributed to oligomerization of RBDs (25.3 kDa) counterbalanced by steric stabilization by a soluble ELP (73.4 kDa). To investigate their biophysical properties, we explored the size, shape, and binding affinity for the human angiotensin-converting enzyme 2 (hACE2) and cellular uptake. Biomimetic nanoparticles such as these may enable future strategies to target the same cells, tissues, and cell–surface receptors as those harnessed by SARS-CoV-2.
Elastin-like polypeptides (ELPs) constitute a genetically engineered class of ‘protein polymers’ derived from human tropoelastin. They exhibit a reversible phase separation whereby samples remain ...soluble below a transition temperature (Tt) but form amorphous coacervates above Tt. Their phase behavior has many possible applications in purification, sensing, activation, and nanoassembly. As humanized polypeptides, they are non-immunogenic, substrates for proteolytic biodegradation, and can be decorated with pharmacologically active peptides, proteins, and small molecules. Recombinant synthesis additionally allows precise control over ELP architecture and molecular weight, resulting in protein polymers with uniform physicochemical properties suited to the design of multifunctional biologics. As such, ELPs have been employed for various uses including as anti-cancer agents, ocular drug delivery vehicles, and protein trafficking modulators. This review aims to offer the reader a catalogue of ELPs, their various applications, and potential for commercialization across a broad spectrum of fields.
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Immune response dynamics in coronavirus disease 2019 (COVID-19) and their severe manifestations have largely been studied in circulation. Here, we examined the relationship between immune processes ...in the respiratory tract and circulation through longitudinal phenotypic, transcriptomic, and cytokine profiling of paired airway and blood samples from patients with severe COVID-19 relative to heathy controls. In COVID-19 airways, T cells exhibited activated, tissue-resident, and protective profiles; higher T cell frequencies correlated with survival and younger age. Myeloid cells in COVID-19 airways featured hyperinflammatory signatures, and higher frequencies of these cells correlated with mortality and older age. In COVID-19 blood, aberrant CD163+ monocytes predominated over conventional monocytes, and were found in corresponding airway samples and in damaged alveoli. High levels of myeloid chemoattractants in airways suggest recruitment of these cells through a CCL2-CCR2 chemokine axis. Our findings provide insights into immune processes driving COVID-19 lung pathology with therapeutic implications for targeting inflammation in the respiratory tract.
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•Airways show localized immune responses correlating to age and outcome in COVID-19•Airway T cells are activated and resident, while myeloid cells are hyperinflammatory•Aberrant CD163hi and HLA-DRlo monocytes predominate in COVID-19 blood•Monocytes infiltrate airways and lung alveoli potentially through a CCL2-CCR2 axis
Through longitudinal profiling of paired airways and blood from patients with severe COVID-19, Szabo et al. reveal airway immune responses that correlate with age and outcome. They further identify coordinate roles for T and myeloid cells in the respiratory tract and circulation in perpetuating lung pathology and disease pathogenesis.
Antibodies possess multiple biologically relevant features that have been engineered into new therapeutic formats. Two examples include the adaptable specificity of their variable (Fv) region and the ...extension of plasma circulation times through their crystallizable (Fc) region. Since the invention of the single chain variable fragment (scFv) in 1988, antibody variable regions have been re-engineered into a wide variety of multifunctional nanostructures. Among these strategies, peptide-mediated self-assembly of variable regions through heterologous expression has become a powerful method to produce homogenous, functional biomaterials. This manuscript reviews recent reports of antibody fragments assembled through fusion with peptides and proteins, including elastin-like polypeptides (ELPs), collagen-like polypeptides (CLPs), albumin, transmembrane proteins, leucine zippers, silk protein, and viruses. This review further discusses the current clinical status of engineered antibody fragments and challenges to overcome.
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This study evaluated a biodegradable drug delivery system for local cancer radiotherapy consisting of a thermally sensitive elastin-like polypeptide (ELP) conjugated to a therapeutic radionuclide. ...Two ELPs (49
kDa) were synthesized using genetic engineering to test the hypothesis that injectable biopolymeric depots can retain radionuclides locally and reduce the growth of tumors. A thermally sensitive polypeptide, ELP
1, was designed to spontaneously undergo a soluble–insoluble phase transition (forming viscous microparticles) between room temperature and body temperature upon intratumoral injection, while ELP
2 was designed to remain soluble upon injection and to serve as a negative control for the effect of aggregate assembly. After intratumoral administration of radionuclide conjugates of ELPs into implanted tumor xenografts in nude mice, their retention within the tumor, spatio-temporal distribution, and therapeutic effect were quantified. The residence time of the radionuclide–ELP
1 in the tumor was significantly longer than the thermally insensitive ELP
2 conjugate. In addition, the thermal transition of ELP
1 significantly protected the conjugated radionuclide from dehalogenation, whereas the conjugated radionuclide on ELP
2 was quickly eliminated from the tumor and cleaved from the biopolymer. These attributes of the thermally sensitive ELP
1 depot improved the antitumor efficacy of iodine-131 compared to the soluble ELP
2 control. This novel injectable and biodegradable depot has the potential to control advanced-stage cancers by reducing the bulk of inoperable tumors, enabling surgical removal of de-bulked tumors, and preserving healthy tissues.
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