Self-assembly of protein-polymer conjugates for drug delivery

Hydrophilic Metal-Organic Frameworks Regulated by Biomineralized Protein for Enhanced Stability and Drug Delivery

For bridging the gap between biological and synthetic materials, the fusion of Metal-Organic Frameworks (MOFs) with biological entities has emerged as a revolutionary strategy in functional materials. In this context, our study introduces a novel structure wherein Bovine Serum Albumin (BSA), a robust and versatile protein, encapsulates zeolitic imidazolate framework-8 (ZIF-8), forming a protein-caged MOF. Highlighting the advantages of this innovative design, the protein-encapsulation enhances the stability and dispersity of ZIF-8, and aids in the synthesis of smaller-sized nanoparticles, crucial for size-impact performance applications. Additionally, the BSA-caged ZIF-8 structure showcases potential in drug delivery applications, especially in the controlled delivery of chemotherapeutic drugs. The study thus elucidates the multifaceted applicability of this novel structure, marking a significant stride in the convergence of biological and synthetic materials.

Heterotelechelic Organometallic PEG Reagents Enable Modular Access to Complex Bioconjugates

Organometallic oxidative addition complexes (OACs) have recently emerged as a powerful class of reagents for the rapid and chemoselective modification of biomolecules. Notably, the steric and electronic properties of the ligand and aryl group can be modified to tune the kinetic profile of the reaction and permit regioselective S-arylation. Using the recently developed dicyclohexylphosphine-based bidentate P,N-ligated Au(III) OACs, we computationally and experimentally examined the effects of sterically bulky and electron deficient aryl substrates to achieve selective S-arylation. With this mechanistic insight, aryl substrates based on 4-iodoanisole and 3,5-dimethyl-4-iodoanisole were incorporated as end groups to generate a heterotelechelic bis-Au(III) poly(ethylene glycol) (PEG). This reagent performed rapid and regioselective S-arylation with a model biomolecule, designed ankyrin repeat protein (DARPin), to form a protein-polymer OAC in situ. This OAC mediated a second S-arylation with biologically relevant thiolated small molecules (metal chelator, saccharide, and fluorophore) and macromolecules (polymer and therapeutic peptide). It is envisioned that this approach could be utilized for the rapid construction of biomacromolecular heteroconjugates with S-aryl linkages.

Polymer- and Lipid-Based Nanostructures Serving Wound Healing Applications: A Review

Management of hard-to-heal wounds often requires specialized care that surpasses the capabilities of conventional treatments. Even the most advanced commercial products lack the functionality to meet the needs of hard-to-heal wounds, especially those complicated by active infection, extreme bleeding, and chronic inflammation. The review explores how supramolecular nanovesicles and nanoparticles-such as dendrimers, micelles, polymersomes, and lipid-based nanocarriers-can be key to introducing advanced wound healing and monitoring properties to address the complex needs of hard-to-heal wounds. Their potential to enable advanced functions essential for next-generation wound healing products-such as hemostatic functions, transdermal penetration, macrophage polarization, targeted delivery, and controlled release of active pharmaceutical ingredients (antibiotics, gaseous products, anti-inflammatory drugs, growth factors)-is discussed via an extensive overview of the recent reports. These studies highlight that the integration of supramolecular systems in wound care is crucial for advancing toward a new generation of wound healing products and addressing significant gaps in current wound management practices. Current strategies and potential improvements regarding personalized therapies, transdermal delivery, and the promising critically evaluated but underexplored polymer-based nanovesicles, including polymersomes and proteinosomes, for wound healing.

Cysteine Conjugation: An Approach to Obtain Polymers with Enhanced Muco- and Tissue Adhesion

The modification of polymers towards increasing their biocompatibility gathers the attention of scientists worldwide. Several strategies are used in this field, among which chemical post-polymerization modification has recently been the most explored. Particular attention revolves around polymer-L-cysteine (Cys) conjugates. Cys, a natural amino acid, contains reactive thiol, amine, and carboxyl moieties, allowing hydrogen bond formation and improved tissue adhesion when conjugated to polymers. Conjugation of Cys and its derivatives to polymers has been examined mostly for hyaluronic acid, chitosan, alginate, polyesters, polyurethanes, poly(ethylene glycol), poly(acrylic acid), polycarbophil, and carboxymethyl cellulose. It was shown that the conjugation of Cys and its derivatives to polymers significantly increased their tissue adhesion, particularly mucoadhesion, stability at physiological pH, drug encapsulation efficiency, drug release, and drug permeation. Conjugates were also non-toxic toward various cell lines. These properties make Cys conjugation a promising strategy for advancing polymer applications in drug delivery systems and tissue engineering. This review aims to provide an overview of these features and to present the conjugation of Cys and its derivatives as a modern and promising approach for enhancing polymer tissue adhesion and its application in the medical field.

Nanocarriers for intracellular delivery of proteins in biomedical applications: strategies and recent advances

Protein drugs are of great importance in maintaining the normal functioning of living organisms. Indeed, they have been instrumental in combating tumors and genetic diseases for decades. Among these pharmaceutical agents, those that target intracellular components necessitate the use of therapeutic proteins to exert their effects within the targeted cells. However, the use of protein drugs is limited by their short half-life and potential adverse effects in the physiological environment. The advent of nanoparticles offers a promising avenue for prolonging the half-life of protein drugs. This is achieved by encapsulating proteins, thereby safeguarding their biological activity and ensuring precise delivery into cells. This nanomaterial-based intracellular protein drug delivery system mitigates the rapid hydrolysis and unwarranted diffusion of proteins, thereby minimizing potential side effects and circumventing the limitations inherent in traditional techniques like electroporation. This review examines established protein drug delivery systems, including those based on polymers, liposomes, and protein nanoparticles. We delve into the operational principles and transport mechanisms of nanocarriers, discussing the various considerations essential for designing cutting-edge delivery platforms. Additionally, we investigate innovative designs and applications of traditional cytosolic protein delivery systems in medical research and clinical practice, particularly in areas like tumor treatment, gene editing and fluorescence imaging. This review sheds light on the current restrictions of protein delivery systems and anticipates future research avenues, aiming to foster the continued advancement in this field.

Atomistic Molecular Dynamics Simulations of ABA-Type Polymer Peptide Conjugates: Insights into Supramolecular Structures and their Circular Dichroism Spectra

A combination of atomistic molecular dynamics (aMD) simulations and circular dichroism (CD) analysis is used to explore supramolecular structures of amphiphilic ABA-type triblock polymer peptide conjugates (PPC). Using the example of a recently introduced PPC with pH- and temperature responsive self-assembling behavior [Otter et al., Macromolecular Rapid Communications 2018, 39, 1800459], this study shows how molecular dynamics simulations of simplified fragment molecules can add crucial information to CD data, which helps to correctly identify the self-assembled structures and monitor the folding/unfolding pathways of the molecules. The findings offer insights into the nature of structural transitions induced by external stimuli, thus contributing to the understanding of the connection of microscopic structures with macroscopic properties.

Self-Assembly of Polymers and Their Applications in the Fields of Biomedicine and Materials

Polymer self-assembly can prepare various shapes and sizes of pores, making it widely used. The complexity and diversity of biomolecules make them a unique class of building blocks for precise assembly. They are particularly suitable for the new generation of biomaterials integrated with life systems as they possess inherent characteristics such as accurate identification, self-organization, and adaptability. Therefore, many excellent methods developed have led to various practical results. At the same time, the development of advanced science and technology has also expanded the application scope of self-assembly of synthetic polymers. By utilizing this technology, materials with unique shapes and properties can be prepared and applied in the field of tissue engineering. Nanomaterials with transparent and conductive properties can be prepared and applied in fields such as electronic displays and smart glass. Multi-dimensional, controllable, and multi-level self-assembly between nanostructures has been achieved through quantitative control of polymer dosage and combination, chemical modification, and composite methods. Here, we list the classic applications of natural- and artificially synthesized polymer self-assembly in the fields of biomedicine and materials, introduce the cutting-edge technologies involved in these applications, and discuss in-depth the advantages, disadvantages, and future development directions of each type of polymer self-assembly.

Investigation of the structure of protein-polymer conjugates in solution reveals the impact of protein deuteration and the size of the polymer on its thermal stability

The conjugation of proteins with polymers offers immense biotechnological potential by creating novel macromolecules. This article presents experimental findings on the structural properties of maltose-binding protein (MBP) conjugated with linear biodegradable polyphosphoester polymers with different molecular weights. We studied isotopic effects on both proteins and polymers. Circular dichroism and fluorescence spectroscopy and small-angle neutron scattering reveal that the conjugation process destabilizes the protein, affecting the secondary more than the tertiary structure, even at room temperature, and that the presence of two domains in the MBP may contribute to its observed instability. Notably, unfolding temperatures differ between native MBP and the conjugates. In particular, this study sheds light on the complex interplay of factors such as the deuteration influencing protein stability and conformational changes in the conjugation processes. The perdeuteration influences the hydrogen bond network and hydrophobic interactions in the case of the MBP protein. The perdeuteration of the protein influences the hydrogen bond network and hydrophobic interactions. This is evident in the decreased thermal stability of deuterated MBP protein, in the conjugate, especially with high-molecular-mass polymers.

The use of proteins and peptides-based therapy in managing and preventing pathogenic viruses

Therapeutic proteins have been employed for centuries and reached approximately 50 % of all drugs investigated. By 2023, they represented one of the top 10 largest-selling pharma products ($387.03 billion) and are anticipated to reach around $653.35 billion by 2030. Growth hormones, insulin, and interferon (IFN α, γ, and β) are among the leading applied therapeutic proteins with a higher market share. Protein-based therapies have opened new opportunities to control various diseases, including metabolic disorders, tumors, and viral outbreaks. Advanced recombinant DNA biotechnology has offered the production of therapeutic proteins and peptides for vaccination, drugs, and diagnostic tools. Prokaryotic and eukaryotic expression host systems, including bacterial, fungal, animal, mammalian, and plant cells usually applied for recombinant therapeutic proteins large-scale production. However, several limitations face therapeutic protein production and applications at the commercial level, including immunogenicity, integrity concerns, protein stability, and protein degradation under different circumstances. In this regard, protein-engineering strategies such as PEGylation, glycol-engineering, Fc-fusion, albumin conjugation, and fusion, assist in increasing targeting, product purity, production yield, functionality, and the half-life of therapeutic protein circulation. Therefore, a comprehensive insight into therapeutic protein research and findings pave the way for their successful implementation, which will be discussed in the current review.

Sub-100 nm carriers by template polymerization for drug delivery applications

Size-controlled drug delivery systems (DDSs) have gained significant attention in the field of pharmaceutical sciences due to their potential to enhance drug efficacy, minimize side effects, and improve patient compliance. This review provides a concise overview of the preparation method, advancements, and applications of size-controlled drug delivery systems focusing on the sub-100 nm size DDSs. The importance of tailoring the size for achieving therapeutic goals is briefly mentioned. We highlight the concept of "template polymerization", a well-established method in covalent polymerization that offers precise control over molecular weight. We demonstrate the utility of this approach in crafting a monolayer of a polymer around biomolecule templates such as DNA, RNA, and protein, achieving the generation of DDSs with sizes ranging from several tens of nanometers. A few representative examples of small-size DDSs that share a conceptual similarity to "template polymerization" are also discussed. This review concludes by briefly discussing the drug release behaviors and the future prospects of "template polymerization" for the development of innovative size-controlled drug delivery systems, which promise to optimize drug delivery precision, efficacy, and safety.

Analysis of Self-Assembled Low- and High-Molecular-Weight Poly-L-Lysine-Ce6 Conjugate-Based Nanoparticles

In cancer therapy, photodynamic therapy (PDT) has attracted significant attention due to its high potential for tumor-selective treatment. However, PDT agents often exhibit poor physicochemical properties, including solubility, necessitating the development of nanoformulations. In this study, we developed two cationic peptide-based self-assembled nanomaterials by using a PDT agent, chlorin e6 (Ce6). To manufacture biocompatible nanoparticles based on peptides, we used the cationic poly-L-lysine peptide, which is rich in primary amines. We prepared low- and high-molecular-weight poly-L-lysine, and then evaluated the formation and performance of nanoparticles after chemical conjugation with Ce6. The results showed that both molecules formed self-assembled nanoparticles by themselves in saline. Interestingly, the high-molecular-weight poly-L-lysine and Ce6 conjugates (HPLCe6) exhibited better self-assembly and PDT performance than low-molecular-weight poly-L-lysine and Ce6 conjugates (LPLCe6). Moreover, the HPLCe6 conjugates showed superior cellular uptake and exhibited stronger cytotoxicity in cell toxicity experiments. Therefore, it is functionally beneficial to use high-molecular-weight poly-L-lysine in the manufacturing of poly-L-lysine-based self-assembling biocompatible PDT nanoconjugates.

Polymer-Protein Assemblies with Tunable Vesicular and Hierarchical Nanostructures

The construction of variable structured multi-protein nano-assemblies is of great interest for the development of protein-based therapeutic systems. This study showcases the synthesis of polymer-protein assemblies with tunable structure like single- and multi-layer polymer-crosslinked protein vesicles, Janus protein vesicles and other hierarchical-structured assemblies by utilizing a dynamic template-assistant intermittent-assembly approach. The generalization of the methodology helps the protein assemblies to gain notable functional complexity. And we demonstrate compelling evidence highlighting the substantial impact of the topological morphology of protein nanoaggregates on their cellular uptake capacity.

Conjugates of amphotericin B to resolve challenges associated with its delivery

INTRODUCTION

Amphotericin B (AmB), a promising antifungal and antileishmanial drug, acts on the membrane of microorganisms. The clinical use of AmB is limited due to issues associated with its delivery including poor solubility and bioavailability, instability in acidic media, poor intestinal permeability, dose and aggregation state dependent toxicity, parenteral administration, and requirement of cold chain for transport and storage, etc.

AREAS COVERED

Scientists have formulated and explored various covalent conjugates of AmB to reduce its toxicity with increase in solubility, oral bioavailability, and payload or loading of AmB by using various polymers, lipids, carbon-based nanocarriers, metallic nanoparticles, and vesicular carriers, etc. In this article, we have reviewed various conjugates of AmB with polymers and nanomaterials explored for its delivery to give a deep insight regarding further exploration in future.

EXPERT OPINION

Covalent conjugates of AmB have been investigated by scientists, and preliminary in vitro and animal investigations have given successful results, which are required to be validated further with systematic investigation on safety and therapeutic efficacy in animals followed by clinical trials.

Self-Assembly of Epitope-Tagged Proteins and Antibodies for Delivering Biologics to Antigen Presenting Cells

Inspired by the immune system's own strategy for macrophage activation, we describe here a simple self-assembly strategy for generating artificial immune complexes. The built-in recognition domains in the antibody, viz. the Fab and Fc domains, are judiciously leveraged for cargo conjugation to generate the nanoassembly and macrophage targeting, respectively. A responsive linker is engineered into the nanoassembly for releasing the protein cargo inside the macrophages, while ensuring stability during delivery. The design principles are simple and versatile to be applicable to a range of biologics, from small protein toxins to large enzymes, with high loading capacity. This self-assembly platform has the potential for delivering biologics to immune cells with implications in immunotherapy.

Bioconjugation Techniques for Enhancing Stability and Targeting Efficiency of Protein and Peptide Therapeutics

Bioconjugation techniques have emerged as powerful tools for enhancing the stability and targeting efficiency of protein and peptide therapeutics. This review provides a comprehensive analysis of the various bioconjugation strategies employed in the field. The introduction highlights the significance of bioconjugation techniques in addressing stability and targeting challenges associated with protein and peptide-based drugs. Chemical and enzymatic bioconjugation methods are discussed, along with crosslinking strategies for covalent attachment and site-specific conjugation approaches. The role of bioconjugation in improving stability profiles is explored, showcasing case studies that demonstrate successful stability enhancement. Furthermore, bioconjugation techniques for ligand attachment and targeting are presented, accompanied by examples of targeted protein and peptide therapeutics. The review also covers bioconjugation approaches for prolonging circulation and controlled release, focusing on strategies to extend half-life, reduce clearance, and design-controlled release systems. Analytical characterization techniques for bioconjugates, including the evaluation of conjugation efficiency, stability, and assessment of biological activity and targeting efficiency, are thoroughly examined. In vivo considerations and clinical applications of bioconjugated protein and peptide therapeutics, including pharmacokinetic and pharmacodynamic considerations, as well as preclinical and clinical developments, are discussed. Finally, the review concludes with an overview of future perspectives, emphasizing the potential for novel conjugation methods and advanced targeting strategies to further enhance the stability and targeting efficiency of protein and peptide therapeutics.

Macromolecular Polymer Based Complexes: A Diverse Strategy for the Delivery of Nucleotides

This review explores the burgeoning field of macromolecular polymer-based complexes, highlighting their revolutionary potential for the delivery of nucleotides for therapeutic applications. These complexes, ingeniously crafted from a variety of polymers, offer a unique solution to the challenges of nucleotide delivery, including protection from degradation, targeted delivery, and controlled release. The focus of this report is primarily on the design principles, encapsulation strategies, and biological interactions of these complexes, with an emphasis on their biocompatibility, biodegradability, and ability to form diverse structures, such as nanoparticles and micelles. Significant attention is paid to the latest advancements in polymer science that enable the precise tailoring of these complexes for specific nucleotides, such as DNA, RNA, and siRNA. The review discusses the critical role of surface modifications and the incorporation of targeting ligands in enhancing cellular uptake and ensuring delivery to specific tissues or cells, thereby reducing off-target effects and improving therapeutic efficacy. Clinical applications of these polymer-based delivery systems are thoroughly examined with a focus on their use in treating genetic disorders, cancer, and infectious diseases. The review also addresses the challenges and limitations currently faced in this field, such as scalability, manufacturing complexities, and regulatory hurdles. Overall, this review provides a comprehensive overview of the current state and future prospects of macromolecular polymer-based complexes in nucleotide delivery. It underscores the significance of these systems in advancing the field of targeted therapeutics and their potential to reshape the landscape of medical treatment for a wide range of diseases.

Polymersome Membrane Engineering with Active Targeting or Controlled Permeability for Responsive Drug Delivery

Polymersomes have been extensively investigated for drug delivery as nanocarriers for two decades due to a series of advantages including high stability under physiological conditions, simultaneous encapsulation of hydrophilic and hydrophobic drugs inside inner cavities and membranes, respectively, and facile adjustment of membrane and surface properties, as well as controlled drug release through incorporation of stimuli-responsive components. Despite these features, polymersome nanocarriers frequently suffer from nontargeting delivery and poor membrane permeability. In recent years, polymersomes have been functionalized for more efficient drug delivery. The surface shells were explored to be modified with diverse active targeting groups to improve disease-targeting delivery. The membrane permeability of the polymersomes was adjusted by incorporation of the stimuli-responsive components for smart controlled transportation of the encapsulated drugs. Therefore, being the polymersome-biointerface, tailorable properties can be introduced by its carefully modulated engineering. This review elaborates on the role of polymersome membranes as a platform to incorporate versatile features. First, we discuss how surface functionalization facilitates the directional journey to the targeting sites toward specific diseases, cells, or intracellular organelles via active targeting. Moreover, recent advances in the past decade related to membrane permeability to control drug release are also summarized. We finally discuss future development to promote polymersomes as in vivo drug delivery nanocarriers.

Copolymer Micelles: A Focus on Recent Advances for Stimulus-Responsive Delivery of Proteins and Peptides

Historically used for the delivery of hydrophobic drugs through core encapsulation, amphiphilic copolymer micelles have also more recently appeared as potent nano-systems to deliver protein and peptide therapeutics. In addition to ease and reproducibility of preparation, micelles are chemically versatile as hydrophobic/hydrophilic segments can be tuned to afford protein immobilization through different approaches, including non-covalent interactions (e.g., electrostatic, hydrophobic) and covalent conjugation, while generally maintaining protein biological activity. Similar to many other drugs, protein/peptide delivery is increasingly focused on stimuli-responsive nano-systems able to afford triggered and controlled release in time and space, thereby improving therapeutic efficacy and limiting side effects. This short review discusses advances in the design of such micelles over the past decade, with an emphasis on stimuli-responsive properties for optimized protein/peptide delivery.

A curcumin-crosslinked bilayer film of soy protein isolate and chitosan with enhanced antibacterial property for beef preservation and freshness monitoring

In this study, antibacterial and antioxidant bilayer films were prepared by using curcumin (Cur) crosslinked soy rotein isolate (SPI) and chitosan (CS). Molecular docking simulations and multispectral analysis revealed that hydrogen bonding and hydrophobic interactions were the primary driving forces that promoted the self-assembly of the bilayer films. The tensile strength, the UV-blocking properties and the hydrophobicity was greatly improved of the bilayer antimicrobial films. Moreover, water vapor permeability, thermal shrinkage and opacity were all reduced significantly. In addition, the composite films with curcumin demonstrated effective antioxidant activity and a slow release characteristic. Morphology observation of the bacteria by AFM revealed that the antibacterial bilayer film had a significant damaging effect on the cell structures of S. aureus and E. coli due to the dual antibacterial effect of curcumin and chitosan. SPI + Cur-CS antimicrobial bilayer film effectively inhibited the growth of bacteria and extended the shelf life of beef. According to the findings, SPI + Cur-CS antimicrobial bilayer film can be used as an active package material for beef preservation and freshness monitoring.

Intracellular delivery of therapeutic proteins. New advancements and future directions

Achieving the full potential of therapeutic proteins to access and target intracellular receptors will have enormous benefits in advancing human health and fighting disease. Existing strategies for intracellular protein delivery, such as chemical modification and nanocarrier-based protein delivery approaches, have shown promise but with limited efficiency and safety concerns. The development of more effective and versatile delivery tools is crucial for the safe and effective use of protein drugs. Nanosystems that can trigger endocytosis and endosomal disruption, or directly deliver proteins into the cytosol, are essential for successful therapeutic effects. This article aims to provide a brief overview of the current methods for intracellular protein delivery to mammalian cells, highlighting current challenges, new developments, and future research opportunities.

Polymerization-Induced Self-Assembly: An Emerging Tool for Generating Polymer-Based Biohybrid Nanostructures

The combination of biomolecules and synthetic polymers provides an easy access to utilize advantages from both the synthetic world and nature. This is not only important for the development of novel innovative materials, but also promotes the application of biomolecules in various fields including medicine, catalysis, and water treatment, etc. Due to the rapid progress in synthesis strategies for polymer nanomaterials and deepened understanding of biomolecules' structures and functions, the construction of advanced polymer-based biohybrid nanostructures (PBBNs) becomes prospective and attainable. Polymerization-induced self-assembly (PISA), as an efficient and versatile technique in obtaining polymeric nano-objects at high concentrations, has demonstrated to be an attractive alternative to existing self-assembly procedures. Those advantages induce the focus on the fabrication of PBBNs via the PISA technique. In this review, current preparation strategies are illustrated based on the PISA technique for achieving various PBBNs, including grafting-from and grafting-through methods, as well as encapsulation of biomolecules during and subsequent to the PISA process. Finally, advantages and drawbacks are discussed in the fabrication of PBBNs via the PISA technique and obstacles are identified that need to be overcome to enable commercial application.

Self-Assembly of Block Copolymers in Thin Films Swollen-Rich in Solvent Vapors

In this study we have employed a polymer processing method based on solvent vapor annealing in order to condense relatively large amounts of solvent vapors onto thin films of block copolymers and thus to promote their self-assembly into ordered nanostructures. As revealed by the atomic force microscopy, a periodic lamellar morphology of poly(2-vinylpyridine)-b-polybutadiene and an ordered morphology comprised of hexagonally-packed structures made of poly(2-vinylpyridine)-b-poly(cyclohexyl methacrylate) were both successfully generated on solid substrates for the first time.

Proteinosomes via Self-Assembly of Thermoresponsive Miktoarm Polymer Protein Bioconjugates

To fabricate nanoscale proteinosomes, thermoresponsive miktoarm polymer protein bioconjugates were prepared through highly efficient molecular recognition between the β-cyclodextrin modified BSA (CD-BSA) and the adamantyl group anchored at the junction point of the thermoresponsive block copolymer poly(ethylene glycol)-b-poly(di(ethylene glycol) methyl ether methacrylate) (PEG-b-PDEGMA). PEG-b-PDEGMA was synthesized by the Passerini reaction of benzaldehyde-modified PEG, 2-bromo-2-methylpropionic acid, and 1-isocyanoadamantane, followed by the atom transfer radical polymerization of DEGMA. Two block copolymers with different chain lengths of PDEGMA were prepared, and both self-assembled into polymersomes at a temperature above their lower critical solution temperatures (LCST). The two copolymers can undergo molecular recognition with the CD-BSA and form miktoarm star-like bioconjugates. The bioconjugates self-assembled into ∼160 nm proteinosomes at a temperature above their LCSTs, and the miktoarm star-like structure has a great effect on the formation of the proteinosomes. Most of the secondary structure and esterase activity of BSA in the proteinosomes were maintained. The proteinosomes exhibited low toxicity to the 4T1 cells and could deliver model drug doxorubicin into the 4T1 cells.

Sustained release of GLP-1 analog from γ-PGA-PAE copolymers for management of type 2 diabetes

GLP-1 has been clinically exploited for treating type 2 diabetes, while its short circulation half-life requires multiple daily injections to maintain effective glycemic control, thus limiting its widespread application. Here we developed a drug delivery system based on self-assembling polymer-amino acid conjugates (γ-PGA-PAE) to provide sustained release of GLP-1 analog (DLG3312). The DLG3312 loaded γ-PGA based nanoparticles (DLG3312@NPs) exhibited a spherical shape with a good monodispersity under transmission electron microscope (TEM) observation. The DLG3312 encapsulation was optimized, and the loading efficiency was as high as 78.4 ± 2.2 %. The transformation of DLG3312@NPs to network structures was observed upon treatment with the fresh serum, resulting in a sustained drug release. The in vivo long-term hypoglycemic assays indicated that DLG3312@NPs significantly reduced blood glucose and glycosylated hemoglobin level. Furthermore, DLG3312@NPs extended the efficacy of DLG3312, leading to a decrease in the dosing schedule that from once a day to once every other day. This approach combined the molecular and materials engineering strategies that offered a unique solution to maximize the availability of anti-diabetic drug and minimize its burdens to type 2 diabetic patients.

Recent Progress in Proteins-Based Micelles as Drug Delivery Carriers

Proteins-derived polymeric micelles have gained attention and revolutionized the biomedical field. Proteins are considered a favorable choice for developing micelles because of their biocompatibility, harmlessness, greater blood circulation and solubilization of poorly soluble drugs. They exhibit great potential in drug delivery systems as capable of controlled loading, distribution and function of loaded agents to the targeted sites within the body. Protein micelles successfully cross biological barriers and can be incorporated into various formulation designs employed in biomedical applications. This review emphasizes the recent advances of protein-based polymeric micelles for drug delivery to targeted sites of various diseases. Most studied protein-based micelles such as soy, gelatin, casein and collagen are discussed in detail, and their applications are highlighted. Finally, the future perspectives and forthcoming challenges for protein-based polymeric micelles have been reviewed with anticipated further advances.

A Cu+ /Thiourea Dendrimer Achieves Excellent Cytosolic Protein Delivery via Enhanced Cell Uptake and Endosome Escape

Intracellular protein delivery has attracted considerable attention in the development of protein-based therapeutics, however, the design of highly efficient materials for robust delivery of native proteins remains challenging. This study proposes a Cu⁺ -based coordination polymer for cytosolic protein delivery with high efficacy and robustness. The phenylthiourea grafted dendrimer is coordinated with cuprous ions to prepare the polymeric carrier, which efficiently bind cargo proteins via a combination of coordination, ionic and hydrophobic interactions. The incorporation of Cu⁺ ions in the polymer greatly improves its cellular uptake and endosomal escape. The cuprous-based coordination polymer successfully delivered a variety of structurally diverse proteins into various cell lines with reserved bioactivities. This study provides a new type of coordination polymers for cytosolic delivery of biomacromolecules.

Investigation of the Conditions for the Synthesis of Poly(3,4-ethylenedioxythiophene) ATRP Macroinitiator

One of the most widely used conductive polymers in the growing conductive polymer industry is poly(3,4-ethylenedioxythiophene) (PEDOT), whose main advantages are good thermal and chemical stability, a conjugated backbone, and ease of functionalization. The main drawback of PEDOT for use as wearable electronics is the lack of stretchable and self-healing properties. This can be overcome by grafting PEDOT with flexible side branches. As pure PEDOT is highly stable and grafting would not be possible, a new bromine-functionalized thiophene derivative, 2-(tiophen-3-yl) ethyl 2-bromo-2-methylpropanoate (ThBr), was synthesized and copolymerized with EDOT for the synthesis of a poly(EDOT-co-ThBr) ATRP macroinitiator. After the synthesis of the macroinitiator, flexible polymers could be introduced as side branches by atom-transfer radical polymerization (ATRP) to modify mechanical properties. Before this last synthesis step, the conditions for the synthesis of the ATRP macroinitiator should be investigated, as only functionalized units can function as grafting sites. In this study, nine new copolymers with different monomer ratios were synthesized to investigate the reactivity of each monomer. The ratios used in the different syntheses were ThBr:EDOT = 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, 0.8:1, 0.6:1, 0.4:1, and 0.2:1. In order to determine the effect of reaction time on the final properties of the polymer, macroinitiator synthesis at a 1:1 ratio was carried out at different time periods: 8 h, 16 h, 24 h, and 48 h. The obtained products were characterized by different techniques, and it was found that polymerizations longer than 24 h yielded practically insoluble macroinitiators, thus limiting its further application. Reactivity ratios of both monomers were found to be similar and close to 1, making the copolymerization reaction symmetrical and the obtained macroinitiators almost random copolymers.

Polymerisation-Induced Self-Assembly of Graft Copolymers

We report the polymerisation-induced self-assembly of poly(lauryl methacrylate)-graft-poly(benzyl methacrylate) copolymers during reversible addition-fragmentation chain transfer (RAFT) grafting from polymerisation in a backbone-selective solvent. Electron microscopy images suggest the phase separation of grafts to result in a network of spherical particles, due to the ability of the branched architecture to freeze chain entanglements and to bridge core domains. Small-angle X-ray scattering data suggest the architecture promotes the formation of multicore micelles, the core morphology of which transitions from spheres to worms, vesicles, and inverted micelles with increasing volume fraction of the grafts. A time-resolved SAXS study is presented to illustrate the formation of the inverted phase during a polymerisation. The grafted architecture gives access to unusual morphologies and provides exciting new handles for controlling the polymer structure and material properties.

Biomimetic Mineralization of Iron-Fumarate Nanoparticles for Protective Encapsulation and Intracellular Delivery of Proteins

Biomimetic mineralization of proteins and nucleic acids into hybrid metal-organic nanoparticles allows for protection and cellular delivery of these sensitive and generally membrane-impermeable biomolecules. Although the concept is not necessarily restricted to zeolitic imidazolate frameworks (ZIFs), so far reports about intracellular delivery of functional proteins have focused on ZIF structures. Here, we present a green room-temperature synthesis of amorphous iron-fumarate nanoparticles under mildly acidic conditions in water to encapsulate bovine serum albumin (BSA), horseradish peroxidase (HRP), green fluorescent protein (GFP), and Cas9/sgRNA ribonucleoproteins (RNPs). The synthesis conditions preserve the activity of enzymatic model proteins and the resulting nanoparticles deliver functional HRP and Cas9 RNPs into cells. Incorporation into the iron-fumarate nanoparticles preserves and protects the activity of RNPs composed of the acid-sensitive Cas9 protein and hydrolytically labile RNA even during exposure to pH 3.5 and storage for 2 months at 4 °C, which are conditions that strongly impair the functionality of unprotected RNPs. Thus, the biomimetic mineralization into iron-fumarate nanoparticles presents a versatile platform for the delivery of biomolecules and protects them from degradation during storage under challenging conditions.

Self-assembling nanocarriers from engineered proteins: Design, functionalization, and application for drug delivery

Self-assembling proteins are valuable building blocks for constructing drug nanocarriers due to their self-assembly behavior, monodispersity, biocompatibility, and biodegradability. Genetic and chemical modifications allow for modular design of protein nanocarriers with effective drug encapsulation, targetability, stimuli responsiveness, and in vivo half-life. Protein nanocarriers have been developed to deliver various therapeutic molecules including small molecules, proteins, and nucleic acids with proven in vitro and in vivo efficacy. This article reviews recent advances in protein nanocarriers that are not derived from natural protein nanostructures, such as protein cages or virus like particles. The protein nanocarriers described here are self-assembled from rationally or de novo designed recombinant proteins, as well as recombinant proteins complexed with other biomolecules, presenting properties that are unique from those of natural protein carriers. Design, functionalization, and therapeutic application of protein nanocarriers will be discussed.

Self-fused concatenation of interferon with enhanced bioactivity, pharmacokinetics and antitumor efficacy

We report an easy but universal protein modification approach, self-fused concatenation (SEC), to biosynthesize a set of interferon (IFN) concatemers with improved in vitro bioactivity, in vivo pharmacokinetics and therapeutic efficacy over the monomeric IFN, and the results can be positively enhanced by the concatenated number of self-fused proteins.

Understanding Supramolecular Assembly of Supercharged Proteins

Ordered supramolecular assemblies have recently been created using electrostatic interactions between oppositely charged proteins. Despite recent progress, the fundamental mechanisms governing the assembly of oppositely supercharged proteins are not fully understood. Here, we use a combination of experiments and computational modeling to systematically study the supramolecular assembly process for a series of oppositely supercharged green fluorescent protein variants. We show that net charge is a sufficient molecular descriptor to predict the interaction fate of oppositely charged proteins under a given set of solution conditions (e.g., ionic strength), but the assembled supramolecular structures critically depend on surface charge distributions. Interestingly, our results show that a large excess of charge is necessary to nucleate assembly and that charged residues not directly involved in interprotein interactions contribute to a substantial fraction (∼30%) of the interaction energy between oppositely charged proteins via long-range electrostatic interactions. Dynamic subunit exchange experiments further show that relatively small, 16-subunit assemblies of oppositely charged proteins have kinetic lifetimes on the order of ∼10-40 min, which is governed by protein composition and solution conditions. Broadly, our results inform how protein supercharging can be used to create different ordered supramolecular assemblies from a single parent protein building block.

Biodegradable Magnetic Molecularly Imprinted Anticancer Drug Carrier for the Targeted Delivery of Docetaxel

Molecularly imprinted biodegradable polymers are receiving considerable attention in drug delivery due to their ability of targeted recognition and biocompatibility. This study reports the synthesis of a novel fluorescence-active magnetic molecularly imprinted drug carrier (MIDC) using a glucose-based biodegradable cross-linking agent for the delivery of anticancer drug docetaxel. The magnetic molecularly imprinted polymer (MMIP) was characterized through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy, and vibrating sample magnetometry (VSM). The MMIP presented a magnetization value of 0.0059 emu g^-1 and binding capacity of 72 mg g^-1 with docetaxel. In vitro and in vivo studies were performed to observe the effectiveness of the MIDC for drug delivery. The cell viability assay suggested that the MMIP did not present toxic effects on healthy cells. The magnetic property of the MMIP allowed quick identification of the drug carrier at the target site by applying the external magnetic field to mice (after 20 min of loading) and taking X-ray images. The novel MMIP-based drug carrier could thus deliver the drug at the target site without affecting the healthy cells.

New Advances in Biomedical Application of Polymeric Micelles

In the last decade, nanomedicine has arisen as an emergent area of medicine, which studies nanometric systems, namely polymeric micelles (PMs), that increase the solubility and the stability of the encapsulated drugs. Furthermore, their application in dermal drug delivery is also relevant. PMs present unique characteristics because of their unique core-shell architecture. They are colloidal dispersions of amphiphilic compounds, which self-assemble in an aqueous medium, giving a structure-type core-shell, with a hydrophobic core (that can encapsulate hydrophobic drugs), and a hydrophilic shell, which works as a stabilizing agent. These features offer PMs adequate steric protection and determine their hydrophilicity, charge, length, and surface density properties. Furthermore, due to their small size, PMs can be absorbed by the intestinal mucosa with the drug, and they transport the drug in the bloodstream until the therapeutic target. Moreover, PMs improve the pharmacokinetic profile of the encapsulated drug, present high load capacity, and are synthesized by a reproducible, easy, and low-cost method. In silico approaches have been explored to improve the physicochemical properties of PMs. Based on this, a computer-aided strategy was developed and validated to enable the delivery of poorly soluble drugs and established critical physicochemical parameters to maximize drug loading, formulation stability, and tumor exposure. Poly(2-oxazoline) (POx)-based PMs display unprecedented high loading concerning water-insoluble drugs and over 60 drugs have been incorporated in POx PMs. Among various stimuli, pH and temperature are the most widely studied for enhanced drug release at the site of action. Researchers are focusing on dual (pH and temperature) responsive PMs for controlled and improved drug release at the site of action. These dual responsive systems are mainly evaluated for cancer therapy as certain malignancies can cause a slight increase in temperature and a decrease in the extracellular pH around the tumor site. This review is a compilation of updated therapeutic applications of PMs, such as PMs that are based on Pluronics^®, micelleplexes and Pox-based PMs in several biomedical applications.

Palladium Mediated Synthesis of Protein-Polyarene Conjugates

Catalyst transfer polymerization (CTP) is widely applied to the synthesis of well-defined π-conjugated polymers. Unlike other polymerization reactions that can be performed in water (e.g., controlled radical polymerizations and ring-opening polymerizations), CTP has yet to be adapted for the modification of biopolymers. Here, we report the use of protein-palladium oxidative addition complexes (OACs) that enable catalyst transfer polymerization to furnish protein-polyarene conjugates. These polymerizations occur with electron-deficient monomers in aqueous buffers open to air at mild (≤37 °C) temperatures with full conversion of the protein OAC and an average polymer length of nine repeating units. Proteins with polyarene chains terminated with palladium OACs can be readily isolated. Direct evidence of protein-polyarene OAC formation was obtained using mass spectrometry, and all protein-polyarene chain ends were uniformly functionalized via C-S arylation to terminate the polymerization with a small molecule thiol or a cysteine-containing protein.

Ultraslow Biological Water-Like Dynamics in Waterless Liquid Protein

Fluorescence correlation spectroscopy and time-dependent fluorescence Stokes shift have been employed to elucidate dynamics in different time scales, ranging from picoseconds to nanoseconds, for human serum albumin, in its native and cationized forms as well as in the self-assembled complex of the cationized protein with the polymer surfactant (PS) glycolic acid ethoxylate lauryl ether. The effect of crowding in this complex, especially in the waterless condition, is of prime importance in this context. Excellent correlation of the dynamics with the structures, obtained by circular dichroism and Fourier transform infrared spectroscopy, has been observed. Slow solvation, associated classically with biological water, has been observed in these systems, even in the waterless condition. This apparently intriguing observation has been rationalized by the relaxation of segments of the protein and the PS in the microenvironment of the fluorescent probe.

Recent development in fabrication and evaluation of phenolic-dietary fiber composites for potential treatment of colonic diseases

Phenolics have been shown by in vitro and animal studies to have multiple pharmacological effects against various colonic diseases. However, their efficacy against colonic diseases, such as inflammatory bowel diseases, Crohn's disease, and colorectal cancer, is significantly compromised due to their chemical instability and susceptibility to modification along the gastrointestinal tract (GIT) before reaching the colonic site. Dietary fibers are promising candidates that can form phenolic-dietary fiber composites (PDC) to carry phenolics to the colon, as they are natural polysaccharides that are non-digestible in the upper intestinal tract but can be partially or fully degradable by gut microbiota in the colon, triggering the release at this targeted site. In addition, soluble and fermentable dietary fibers confer additional health benefits as prebiotics when used in the PDC fabrication, and the possibility of synergistic relationship between phenolics and fibers in alleviating the disease conditions. The functionalities of PDC need to be characterized in terms of their particle characteristics, molecular interactions, release profiles in simulated digestion and colonic fermentation to fully understand the metabolic fate and health benefits. This review examines recent advancements regarding the approaches for fabrication, characterization, and evaluation of PDC in in vitro conditions.

Protein-, (Poly)peptide-, and Amino Acid-Based Nanostructures Prepared via Polymerization-Induced Self-Assembly

Proteins and peptides, built from precisely defined amino acid sequences, are an important class of biomolecules that play a vital role in most biological functions. Preparation of nanostructures through functionalization of natural, hydrophilic proteins/peptides with synthetic polymers or upon self-assembly of all-synthetic amphiphilic copolypept(o)ides and amino acid-containing polymers enables access to novel protein-mimicking biomaterials with superior physicochemical properties and immense biorelevant scope. In recent years, polymerization-induced self-assembly (PISA) has been established as an efficient and versatile alternative method to existing self-assembly procedures for the reproducible development of block copolymer nano-objects in situ at high concentrations and, thus, provides an ideal platform for engineering protein-inspired nanomaterials. In this review article, the different strategies employed for direct construction of protein-, (poly)peptide-, and amino acid-based nanostructures via PISA are described with particular focus on the characteristics of the developed block copolymer assemblies, as well as their utilization in various pharmaceutical and biomedical applications.