Nano and microscale delivery platforms for enhanced oral peptide/protein bioavailability

Loading bioactive peptides within different nanocarriers to enhance their functionality and bioavailability; in vitro and in vivo studies

A hydrolyzed protein is a blend of peptides and amino acids which is the result of hydrolysis by enzymes, acids or alkalis. The Bioactive Peptides (BPs) show important biological roles including antioxidant, antimicrobial, anti-diabetic, anti-cancer, and anti-hypertensive effects, as well as positive effects on the immune, nervous, and digestive systems. Despite the benefits of BPs, challenges such as undesired organoleptic properties, solubility profile, chemical instability, and low bioavailability limit their use in functional food formulations and dietary supplements. Nanocarriers have emerged as a promising solution for overcoming these challenges by improving the stability, solubility, resistance to gastric digestion, and bioavailability, allowing for the targeted and controlled delivery, and reduction or masking of the undesirable flavor of BPs. This study reviews the recent scientific accomplishments concerning the loading of BPs into various nanocarriers including lipid, carbohydrate and protein based-nanocarriers. A special emphasis is given to their application in food formulations in accordance to the challenges associated with their use.

Nano- and Micro-Platforms in Therapeutic Proteins Delivery for Cancer Therapy: Materials and Strategies

Proteins have emerged as promising therapeutics in oncology due to their great specificity. Many treatment strategies are developed based on protein biologics, such as immunotherapy, starvation therapy, and pro-apoptosis therapy, while some protein biologics have entered the clinics. However, clinical translation is severely impeded by instability, short circulation time, poor transmembrane transportation, and immunogenicity. Micro- and nano-particles-based drug delivery platforms are designed to solve those problems and enhance protein therapeutic efficacy. This review first summarizes the different types of therapeutic proteins in clinical and research stages, highlighting their administration limitations. Next, various types of micro- and nano-particles are described to demonstrate how they can overcome those limitations. The potential of micro- and nano-particles are then explored to enhance the therapeutic efficacy of proteins by combinational therapies. Finally, the challenges and future directions of protein biologics carriers are discussed for optimized protein delivery.

Laponite nanoclays for the sustained delivery of therapeutic proteins

Protein therapeutics hold immense promise for treating a wide array of diseases. However, their efficacy is often compromised by rapid degradation and clearance. The synthetic smectite clay Laponite emerges as a promising candidate for their sustained delivery. Despite its unique properties allow to load and release proteins mitigating burst release and extending their effects, precise control over Laponite-protein interactions remains challenging since it depends on a complex interplay of factors whose implication is not fully understood yet. The aim of this review article is to shed light on this issue, providing a comprehensive discussion of the factors influencing protein loading and release, including the physicochemical properties of the nanoclay and proteins, pH, dispersion buffer, clay/protein concentration and Laponite degradation. Furthermore, we thoroughly revise the array of bioactive proteins that have been delivered from formulations containing the nanoclay, highlighting Laponite-polymer nanocomposite hydrogels, a promising avenue currently under extensive investigation.

DNA Origami Enhanced Cytokine Immunotherapy for Alleviating Renal Ischemia-Reperfusion Injury

Renal ischemia-reperfusion injury (IRI) is a major contributing factor to the development of acute kidney injury (AKI) and has resulted in considerable morbidity and mortality. Persistent inflammatory responses and excessive reactive oxygen species (ROS) in the kidney following IRI can severely delay tissue repair, making it challenging to effectively promote IRI regeneration. Herein, we report an approach to enhance immunotherapy using interleukin-10 (IL-10) to promote IRI regeneration by loading IL-10 onto rectangular DNA origami nanostructures (rDON). rDON can significantly enhance the renal accumulation and retention time of IL-10, enabling it to effectively polarize type 1 macrophages into type 2 macrophages, thereby significantly reducing proinflammatory factors and increasing anti-inflammatory factors. In addition, DNA origami helps mitigate the harmful effects of ROS during renal IRI. The administration of IL-10-loaded DNA origami effectively improves kidney function, resulting in a notable reduction in blood urea nitrogen, serum uric acid, and serum creatinine levels. Our study demonstrates that the integration of anti-inflammatory cytokines within DNA origami holds promise as a strategic approach for cytokine immunotherapy in patients with AKI and other renal disorders.

Food-derived peptides unleashed: emerging roles as food additives beyond bioactivities

Innovating food additives stands as a cornerstone for the sustainable evolution of future food systems. Peptides derived from food proteins exhibit a rich array of physicochemical and biological attributes crucial for preserving the appearance, flavor, texture, and nutritional integrity of foods. Leveraging these peptides as raw materials holds great promise for the development of novel food additives. While numerous studies underscore the potential of peptides as food additives, existing reviews predominantly focus on their biotic applications, leaving a notable gap in the discourse around their abiotic functionalities, such as their physicochemical properties. Addressing this gap, this review offers a comprehensive survey of peptide-derived food additives in food systems, accentuating the application of peptides' abiotic properties. It furnishes a thorough exploration of the underlying mechanisms and diverse applications of peptide-derived food additives, while also delineating the challenges encountered and prospects for future applications. This well-time review will set the stage for a deeper understanding of peptide-derived food additives.

Developing Plant Exosomes as an Advanced Delivery System for Cosmetic Peptide

Peptides are a promising skincare ingredient, but due to their inherent instability and the barrier function of the skin's surface, they often have limited skin absorption and penetration, which can significantly hinder their skincare benefits. To address this, a novel technique called NanoGlow has been introduced for encapsulating peptide-based cosmetic raw materials into engineered nanosized plant-derived exosomes (pExo) to achieve the goal of a healthier and more radiant skin state. In this approach, pExo served as carriers for cosmetic peptides across the intact skin barrier, enhancing their biological effectiveness in skin beauty. The NanoGlow strategy combines chemical activation and physical proencapsulation, boasting a high success rate and straightforward and stable operation, making it suitable for large-scale production. Comprehensive analysis using in vitro cellular absorption and skin penetration models has demonstrated that the nanosized pExo carriers significantly improve peptide penetration into the skin compared to free peptides. Furthermore, in vivo tissue slice studies have shown that pExo carriers efficiently deliver acetyl hexapeptide-8 to the skin's dermis, surpassing the performance of free peptides. Cosmetic skincare effect analysis has also indicated that pExo-loaded cosmetic peptides deliver superior results. Therefore, the NanoGlow technique harnesses the natural size and properties of pExo to maximize the bioavailability of cosmetic peptides, holding great promise for developing advanced peptide delivery systems in both the cosmetic and medical drug industries.

Cell-penetrating peptides for transmucosal delivery of proteins

Enabling non-invasive delivery of proteins across the mucosal barriers promises improved patient compliance and therapeutic efficacies. Cell-penetrating peptides (CPPs) are emerging as a promising and versatile tool to enhance protein and peptide permeation across various mucosal barriers. This review examines the structural and physicochemical attributes of the nasal, buccal, sublingual, and oral mucosa that hamper macromolecular delivery. Recent development of CPPs for overcoming those mucosal barriers for protein delivery is summarized and analyzed. Perspectives regarding current challenges and future research directions towards improving non-invasive transmucosal delivery of macromolecules for ultimate clinical translation are discussed.

Enhancing cell-scale performance via sustained release of the varicella-zoster virus antigen from a microneedle patch under simulated microgravity

The immune system of astronauts might become weakened in the microgravity environment in space, and the dormant varicella-zoster virus (VZV) in the body might be reactivated, seriously affecting their work and safety. For working in orbit for the long term, there is currently no efficient and durable delivery system of general vaccines in a microgravity environment. Accordingly, based on the previous foundation, we designed, modified, and synthesized a biodegradable and biocompatible copolymer, polyethylene glycol-polysulfamethazine carbonate urethane (PEG-PSCU) that could be mainly adopted to fabricate a novel sustained-release microneedle (S-R MN) patch. Compared with conventional biodegradable microneedles, this S-R MN patch could not only efficiently encapsulate protein vaccines (varicella-zoster virus glycoprotein E, VZV gE) but also further prolong the release time of VZV gE in a simulated microgravity (SMG) environment. Eventually, we verified the activation of dendritic cells by VZV gE released from the S-R MN patch in an SMG environment and the positive bioeffect of activated dendritic cells on lymphocytes using an in vitro lymph node model. This study is of great significance for the exploration of long-term specific immune responses to the VZV in an SMG environment.

Anti-inflammatory effect of two novel peptides derived from Binglangjiang buffalo whey protein in lipopolysaccharide-stimulated RAW264.7 macrophages

Whey protein hydrolysate from Binglangjiang buffalo, a unique genetic resource, has anti-inflammatory activity, but its anti-inflammatory composition and effects are unknown. The aim of this study was to investigate the anti-inflammatory peptides from Binglangjiang buffalo whey protein hydrolysate. A total of 1483 peptides were identified using LC-MS/MS, and 12 peptides were chosen for chemical synthesis using peptidomics, and then two novel anti-inflammatory peptides (DQPFFHYN (DN8) and YSPFSSFPR (YR9)) were screened out using LPS-stimulated RAW264.7 cells. The molecular weights of DN8 and YR9 with β-turn conformations were 1067.458 Da and 1087.52 Da, respectively, and showed a high in-vitro safety profile and thermal stability, but were intolerant to pepsin. Furthermore, ELISA and Western blot analysis indicated that peptides DN8 and YR9 significantly suppressed the secretion of pro-inflammatory cytokines NO, TNF-α, and IL-6 and the expression of mediators iNOS, TNF-α, and IL-6 in LPS-stimulated RAW264.7 cells. The study provides insights into the development of novel food-based anti-inflammatory nutritional supplements.

Identification and Validation of Active Ingredient in Cerebrotein Hydrolysate-I Based on Pharmacokinetic and Pharmacodynamic Studies

Cerebrotein hydrolysate-1 (CH-1), a mixture of small peptides, polypeptides, and various amino acids derived from porcine brain, has been widely used in the treatment of cerebral injury. However, the bioactive composition and pharmacokinetics of CH-1 are still unexplored because of their complicated composition and relatively tiny amounts in vivo. Herein, NanoLC Orbitrap Fusion Lumos Tribrid Mass Spectrometer was firstly used to qualitatively analyze the components of CH-1. A total of 1347 peptides were identified, of which 43 peptides were characterized by high mass spectrometry (MS) intensity and identification accuracy. We then innovatively synthesized four main peptides for activity verification, and the results suggested that Pep72 (NYEPPTVVPGGDL) had the strongest neuroprotective effect on both in vivo and in vitro models. Next, a quantitative method for Pep72 was established based on liquid chromatography tandem mass spectrometry (LC-MS/MS) with the aid of Skyline software and then used in its pharmacokinetic studies. The results revealed that Pep72 had a high elimination rate and low exposure in rats. In addition, a hCMEC/D3-based in vitro model was built and firstly used to investigate the transport of Pep72. We found that Pep72 had extremely low blood-brain barrier permeability and was not a substrate of efflux transporters. The biotransformation of Pep72 in rat fresh plasma and tissues was investigated to explore the contradiction between pharmacokinetics and efficacy. A total of 11 main metabolites were structurally identified, with PGGDL and EPPTVPGGDL being the main metabolites of Pep72. Notably, metalloproteinase and cysteine protease were confirmed to be the main enzymes mediating Pep72 metabolism in rat tissues. SIGNIFICANCE STATEMENT: The NanoLC Orbitrap Fusion Lumos Tribrid Mass Spectrometer was firstly applied to discover the components of CH-1, and one main peptide Pep72 (NYEPPTVVPGGDL) was innovatively synthesized and firstly found to have the strongest neuroprotective effect among 1347 peptides identified from CH-1. Our study is the first time to identify and verify the active ingredient of CH-1 from the perspective of pharmacokinetics and pharmacodynamics, and provides a systematic technical platforms and strategies for the active substance research of other protein hydrolysates.

Betaine-Based and Polyguanidine-Inserted Zwitterionic Micelle as a Promising Platform to Conquer the Intestinal Mucosal Barrier

Developing nanocarriers for oral drug delivery is often hampered by the dilemma of balancing mucus permeation and epithelium absorption, since huge differences in surface properties are required for sequentially overcoming these two processes. Inspired by mucus-penetrating viruses that universally possess a dense charge distribution with equal opposite charges on their surfaces, we rationally designed and constructed a poly(carboxybetaine)-based and polyguanidine-inserted cationic micelle platform (hybrid micelle) for oral drug delivery. The optimized hybrid micelle exhibited a great capacity for sequentially overcoming the mucus and villi barriers. It was demonstrated that a longer zwitterionic chain was favorable for mucus diffusion for hybrid micelles but not conducive to cellular uptake. In addition, the significantly enhanced internalization absorption of hybrid micelles was attributed to the synergistic effect of polyguanidine and proton-assisted amine acid transporter 1 (PAT1). Moreover, the retrograde pathway was mainly involved in the intracellular transport of hybrid micelles and transcytosis delivery. Furthermore, the prominent intestinal mucosa absorption in situ and in vivo liver distribution of the oral hybrid micelle were both detected. The results of this study indicated that the hybrid micelles were capable of conquering the intestinal mucosal barrier, having a great potential for oral application of drugs with poor oral bioavailability.

Oral colon-targeted responsive alginate/hyaluronic acid-based hydrogel propels the application of infliximab in colitis

Currently, commercialized infliximab (IFX) has rapidly propelled the clinical treatment of IBD, however, its inherent attributes, such as off-target effects and rapid metabolism, severely limit practical applications. Moreover, high doses injection of IFX can result in IBD treatment failure, which may induce other side effects. In this study, an colon microenvironment-responsive hydrogel (AL/HA hydrogel), consisting of acid-resistant sodium alginate and colon-degraded and targeted hyaluronic acid, was constructed by simple Ca2+/Zn2+ cross-linking. The ion-mediated hydrogel exhibited the protective effect of gastrointestinal tract to avoid early drug leakage, while the inflammation environments showed well-controlled drug release and significant biodegradable behaviors. Additionally, oral hydrogel exhibited long-standing enteritis areas compared with normal mice. Therefore, hydrogel-assisted enteritis treatment has great potential in IBD as an oral agent. After that, IFX was packaged in hydrogel to fabricate a facile oral antibody delivery system to treat IBD. IFX-embedded hydrogel showed remarkable therapeutic effect on IBD compared with free IFX. Surprisingly, oral hydrogel below 7 times IFX achieve the same amount of IFX-infused treatment that will further help alleviate the drawbacks of IFX. Our work elaborated on the efficacy of oral AL/HA@IFX in IBD, providing a guarantee for the future of promoted clinical transformation.

Recent Advances in Formulations for Long-Acting Delivery of Therapeutic Peptides

Recent preclinical and clinical studies have focused on the active area of therapeutic peptides due to their high potency, selectivity, and specificity in treating a broad range of diseases. However, therapeutic peptides suffer from multiple disadvantages, such as limited oral bioavailability, short half-life, rapid clearance from the body, and susceptibility to physiological conditions (e.g., acidic pH and enzymolysis). Therefore, high peptide dosages and dose frequencies are required for effective patient treatment. Recent innovations in pharmaceutical formulations have substantially improved therapeutic peptide administration by providing the following advantages: long-acting delivery, precise dose administration, retention of biological activity, and improvement of patient compliance. This review discusses therapeutic peptides and challenges in their delivery and explores recent peptide delivery formulations, including micro/nanoparticles (based on lipids, polymers, porous silicon, silica, and stimuli-responsive materials), (stimuli-responsive) hydrogels, particle/hydrogel composites, and (natural or synthetic) scaffolds. This review further covers the applications of these formulations for prolonged delivery and sustained release of therapeutic peptides and their impact on peptide bioactivity, loading efficiency, and (in vitro/in vivo) release parameters.

Oral Delivery of Protein Drugs via Lysine Polymer-Based Nanoparticle Platforms

Oral delivery of proteins has opened a new perspective for the treatment of different diseases. However, advances of oral protein formulation are usually hindered by protein susceptibility and suboptimal absorption in the gastrointestinal tract (GIT). Polymeric nano drug delivery systems are considered revolutionary candidates to solve these issues, which can be preferably tunable against specific delivery challenges. Herein, a tailored family of lysine-based poly(ester amide)s (Lys-aaPEAs) is designed as a general oral protein delivery platform for efficient protein loading and protection from degradation. Insulin, as a model protein, can achieve effective internalization by epithelial cells and efficient transport across the intestinal epithelium layer into the systemic circulation, followed by controlled release in physiological environments. After the oral administration of insulin carried by Lys-aaPEAs with ornamental hyaluronic acid (HA), mice with type 1 diabetes mellitus showed an acceptable hypoglycemic effect with alleviated complications. A successful oral insulin delivery is associated with patient comfort and convenience and simultaneously avoids the risk of hypoglycemia compared with injections, which is of great feasibility for daily diabetes therapy. More importantly, this versatile Lys-aaPEAs polymeric library can be recognized as a universal vehicle for oral biomacromolecule delivery, providing more possibilities for treating various diseases.

A high-throughput microfluidic mechanoporation platform to enable intracellular delivery of cyclic peptides in cell-based assays

Cyclic peptides are poised to target historically difficult to drug intracellular protein-protein interactions, however, their general cell impermeability poses a challenge for characterizing function. Recent advances in microfluidics have enabled permeabilization of the cytoplasmic membrane by physical cell deformation (i.e., mechanoporation), resulting in intracellular delivery of impermeable macromolecules in vector- and electrophoretic-free approaches. However, the number of payloads (e.g., peptides) and/or concentrations delivered via microfluidic mechanoporation is limited by having to pre-mix cells and payloads, a manually intensive process. In this work, we show that cells are momentarily permeable (t 1/2 = 1.1-2.8 min) after microfluidic vortex shedding (μVS) and that lower molecular weight macromolecules can be cytosolically delivered upon immediate exposure after cells are processed/permeabilized. To increase the ability to screen peptides, we built a system, dispensing-microfluidic vortex shedding (DμVS), that integrates a μVS chip with inline microplate-based dispensing. To do so, we synced an electronic pressure regulator, flow sensor, on/off dispense valve, and an x-y motion platform in a software-driven feedback loop. Using this system, we were able to deliver low microliter-scale volumes of transiently mechanoporated cells to hundreds of wells on microtiter plates in just several minutes (e.g., 96-well plate filled in <2.5 min). We validated the delivery of an impermeable peptide directed at MDM2, a negative regulator of the tumor suppressor p53, using a click chemistry- and NanoBRET-based cell permeability assay in 96-well format, with robust delivery across the full plate. Furthermore, we demonstrated that DμVS could be used to identify functional, low micromolar, cellular activity of otherwise cell-inactive MDM2-binding peptides using a p53 reporter cell assay in 96- and 384-well format. Overall, DμVS can be combined with downstream cell assays to investigate intracellular target engagement in a high-throughput manner, both for improving structure-activity relationship efforts and for early proof-of-biology of non-optimized peptide (or potentially other macromolecular) tools.

Structure-Based Design of Peptides Targeting VEGF/VEGFRs

Vascular endothelial growth factor (VEGF) and its receptors (VEGFRs) play a main role in the regulation of angiogenesis and lymphangiogenesis. Furthermore, they are implicated in the onset of several diseases such as rheumatoid arthritis, degenerative eye conditions, tumor growth, ulcers and ischemia. Therefore, molecules able to target the VEGF and its receptors are of great pharmaceutical interest. Several types of molecules have been reported so far. In this review, we focus on the structure-based design of peptides mimicking VEGF/VEGFR binding epitopes. The binding interface of the complex has been dissected and the different regions challenged for peptide design. All these trials furnished a better understanding of the molecular recognition process and provide us with a wealth of molecules that could be optimized to be exploited for pharmaceutical applications.

Unstructured Polypeptides as a Versatile Drug Delivery Technology

Although polyethylene glycol (PEG), or "PEGylation" has become a widely applied approach for improving the efficiency of drug delivery, the immunogenicity and non-biodegradability of this synthetic polymer have prompted an evident need for alternatives. To overcome these caveats and to mimic PEG -or other natural or synthetic polymers- for the purpose of drug half-life extension, unstructured polypeptides are designed. Due to their tunable length, biodegradability, low immunogenicity and easy production, unstructured polypeptides have the potential to replace PEG as the preferred technology for therapeutic protein/peptide delivery. This review provides an overview of the evolution of unstructured polypeptides, starting from natural polypeptides to engineered polypeptides and discusses their characteristics. Then, it is described that unstructured polypeptides have been successfully applied to numerous drugs, including peptides, proteins, antibody fragments, and nanocarriers, for half-life extension. Innovative applications of unstructured peptides as releasable masks, multimolecular adaptors and intracellular delivery carriers are also discussed. Finally, challenges and future perspectives of this promising field are briefly presented. STATEMENT OF SIGNIFICANCE: : Polypeptide fusion technology simulating PEGylation has become an important topic for the development of long-circulating peptide or protein drugs without reduced activity, complex processes, and kidney injury caused by PEG modification. Here we provide a detailed and in-depth review of the recent advances in unstructured polypeptides. In addition to the application of enhanced pharmacokinetic performance, emphasis is placed on polypeptides as scaffolders for the delivery of multiple drugs, and on the preparation of reasonably designed polypeptides to manipulate the performance of proteins and peptides. This review will provide insight into future application of polypeptides in peptide or protein drug development and the design of novel functional polypeptides.

Sortase A Inhibitor Protein Nanoparticle Formulations Demonstrate Antibacterial Synergy When Combined with Antimicrobial Peptides

Sortase A (SrtA) is an enzyme which attaches proteins, including virulence factors, to bacterial cell walls. It is a potential target for developing anti-virulence agents against pathogenic and antimicrobial resistant bacteria. This study aimed to engineer 𝛽-lactoglobulin protein nanoparticles (PNPs) for encapsulating safe and inexpensive natural SrtA inhibitors (SrtAIs; trans-chalcone (TC), curcumin (CUR), quercetin (QC), and berberine (BR)) to improve their poor aqueous dispersibility, to screen for synergy with antimicrobial peptides (AMPs), and to reduce the cost, dose, and toxicity of AMPs. Minimum inhibitory concentration (MIC), checkerboard synergy, and cell viability assays were performed for SrtAI PNPs against Gram-positive (methicillin-sensitive and -resistant S. aureus) and Gram-negative (E. coli, P. aeruginosa) bacteria alone and combined with leading AMPs (pexiganan, indolicidin, and a mastoparan derivative). Each SrtAI PNP inhibited Gram-positive (MIC: 62.5-125 µg/mL) and Gram-negative (MIC: 31.3-500 µg/mL) bacterial growth. TC PNPs with pexiganan demonstrated synergy against each bacteria, while BR PNPs with pexiganan or indolicidin provided synergy towards S. aureus. Each SrtAI PNP inhibited SrtA (IC₅₀: 25.0-81.8 µg/mL), and did not affect HEK-293 cell viability at their MIC or optimal synergistic concentrations with AMPs. Overall, this study provides a safe nanoplatform for enhancing antimicrobial synergy to develop treatments for superbug infections.

Crosslinked zwitterionic microcapsules to overcome gastrointestinal barriers for oral insulin delivery

Oral insulin delivery has been extensively considered to achieve great patient compliance and convenience as well as favourable glucose homeostasis. However, its application is highly limited by the low insulin bioavailability owing to gastrointestinal barriers. Herein, we developed crosslinked zwitterionic microcapsules (CB-MCs@INS) based on a carboxyl betaine (CB)-modified poly(acryloyl carbonate-co-caprolactone) copolymer via the combination of microfluidics and UV-crosslinking to improve oral insulin delivery. CB-MC@INS microcapsules with high drug loading capacity (>40%) protected insulin from acid degradation in the harsh gastric environment. Through the introduction of CB-moieties, CB-MCs@INS possessed superior affinity for epithelial cells and improved insulin transport as compared to non-CB modified MCs@INS (5.15-fold), which was mainly attributed to the CB-mediated cell surface transporter via the PAT1 pathway. Moreover, the oral administration of CB-MCs@INS exhibited an excellent hypoglycaemic effect and maintained normoglycemia for up to 8 h in diabetic mice, demonstrating the great potential of crosslinked zwitterionic microcapsules as an oral insulin delivery platform for diabetes therapy.

Decorating hexahistidine-metal assemblies with tyrosine enhances the ability of proteins to pass through corneal biobarriers

In recent decades, the use of protein drugs has increased dramatically for almost every clinical indication, including autoimmunity and cancer infection, given their high specificity and limited side effects. However, their easy deactivation by the surrounding microenvironment and limited ability to pass through biological barriers pose large challenges to the use of these agents for therapeutic effects; these deficits could be greatly improved by nanodelivery using platforms with suitable physicochemical properties. Here, to assess the effect of the hydrophilicity of nanoparticles on their ability to penetrate biological barriers, the hydrophobic amino acid tyrosine (Y) was decorated onto hexahistidine peptide, and two nanosized YHmA and HmA particles were generated, in which Avastin (Ava, a protein drug) was encapsulated by a coassembly strategy. In vitro and in vivo tests demonstrated that these nanoparticles effectively retained the bioactivity of Ava and protected Ava from proteinase K hydrolysis. Importantly, YHmA displayed a considerably higher affinity to the ocular surface than HmA, and YHmA also exhibited the ability to transfer proteins across the barriers of the anterior segment, which greatly improved the bioavailability of the encapsulated Ava and produced surprisingly good therapeutic outcomes in a model of corneal neovascularization. STATEMENT OF SIGNIFICANCE: Improving the ability to penetrate tissue barriers and averting inactivation caused by surrounding environments, are the keys to broaden the application of protein drugs. By decorating hydrophobic amino acid, tyrosine (Y), on hexahistidine peptide, YHmA encapsulated protein drug Ava with high efficiency by co-assembly strategy. YHmA displayed promising ability to maintain bioactivity of Ava during encapsulation and delivery, and protected Ava from proteinase K hydrolysis. Importantly, YHmA transferred Ava across the corneal epithelial barrier and greatly improved its bioavailability, producing surprisingly good therapeutic outcomes in a model of corneal neovascularization. Our results contributed to not only the strategy to overcome shortcomings of protein drugs, but also suggestion on hydrophilicity as a nonnegligible factor in nanodrug penetration through biobarriers.

Orally administrable polyphenol-based nanoparticles achieve anti-inflammation and antitumor treatment of colon diseases

Colorectal cancer is the third most common malignancy that leads to significant mortality around the world. Chronic colonic inflammation could induce a protumor effect by the massive release of pro-inflammatory cytokines, facilitating migration, invasion, and metastasis of malignant cells in colorectal cancer. Therefore, developing a combination regimen of anti-inflammation and antitumor therapies is a promising strategy for the treatment of colorectal cancer. Here, we report that tannic acid-containing nanoparticles, formed by a turbulent-mixing technique, have exhibited uniform size, high stability, and pH-triggered drug release in the gastrointestinal tract, and could overcome intestinal mucosa for drug delivery in the colorectal region. As a drug carrier itself, with potent antioxidant and anti-inflammatory properties, tannic acid-containing nanoparticles showed great therapeutic effect in preventing the development of colitis-associated colorectal cancer (CAC) through oral administration. Furthermore, we used a therapeutic nanocarrier to deliver chemotherapeutic drugs for CAC treatment, generating lower systemic toxicity and superior antitumor performance through concurrent anti-inflammation and antitumor treatment. As a result, we confirmed that the drug carrier itself with therapeutic function could improve the overall therapeutic performance, and provided a safe and effective tannic acid-containing nanoplatform for the prevention and treatment of colon diseases.

One-pot synthesis of high-concentration mixed-shell polymeric micelles as nanochaperones for the renaturation of bulk proteins

A one-pot synthesis of high-concentration mixed-shell polymeric micelles and synthetic nanoparticles can be used to assist the refolding of bulk denatured proteins and stabilize native proteins for long-term storage.

Combatting Helicobacter pylori with oral nanomedicines

Helicobacter pylori (H. pylori) infection is considered to be the main cause of most digestive diseases,such as chronic active gastritis, gastroduodenal ulcers, or even gastric cancer. Oral medication is a transformative approach to treat H. pylori-induced infections. However, unlike intravenous administration, orally administrated drugs have to overcome various barriers before reaching the infected sites, which significantly limits the therapeutic efficacy. These challenges may be addressed by emerging nanomedicine that is equipped with nanotechnology approaches to enable efficient and effective targeted delivery of drugs. Herein, in this review, we first discuss the conventional therapy for the eradication of H. pylori. Through the introduction of the critical barriers of oral administration, the benefits of nanomedicine are highlighted. Recently-published examples of nanocarriers for combating H. pylori in terms of design, preparation, and antimicrobial mechanisms are then presented, followed by our perspective on potential future research directions of oral nanomedicines.

Poly(disulfide)s: From Synthesis to Drug Delivery

Bioresponsive polymers have been widely used in drug delivery because of their degradability. For example, poly(disulfide)s with repeating disulfide bonds in the main chain have attracted considerable research attention. The characteristics of the disulfide bonds, including their dynamic and reversible properties and their responsiveness to stimuli such as reductants, light, heat, and mechanical force, make them ideal platforms for on-demand drug delivery. This review introduces the synthesis methods and applications of poly(disulfide)s. Furthermore, the synthesis methods of poly(disulfide)s are classified on the basis of the monomers used: oxidative step-growth polymerization with dithiols, ring-opening polymerization with cyclic disulfides, and polymerization with linear disulfides. In addition, recent advances in poly(disulfide)s for the delivery of small-molecule or biomacromolecular drugs are discussed. Quantum-dot-loaded poly(disulfide) delivery systems for imaging are also included. This review provides an overview of the various design strategies employed in the construction of poly(disulfide) platforms to inspire new applications in the field of drug delivery.

Oral delivery of infliximab using nano-in-microparticles for the treatment of inflammatory bowel disease

The anti-tumor necrosis factor-α (anti-TNF-α) blocker, has shown great efficacy for the treatment of inflammatory bowel disease (IBD). However, systemic exposure to it can cause considerable safety problems due to reduced suppression of the systemic immune response and loss of response to the production of anti-drug antibodies. Thus, we try to devise a targeted vehicle system for oral administration of anti-TNF-α antibodies for the treatment of IBD. In the present study, we developed an oral Infliximab (IFX) loaded nano-in-microparticles, based on chitosan (CS)/carboxymethyl chitosan (CMC) and alginate (Alg), which could protect IFX from the harsh environment of the gastrointestinal tract and produce targeted drug delivery to the inflamed intestine. In vivo studies demonstrated that the IFX loaded nano-in-micro vehicle can alleviate colitis by ameliorating inflammation and maintaining the intestinal epithelial barrier.

Mitochondria-targeted nanoparticles in treatment of neurodegenerative diseases

Neurodegenerative diseases (NDs) are a class of heterogeneous diseases that includes Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Mitochondria play an important role in oxidative balance and metabolic activity of neurons; therefore, mitochondrial dysfunction is associated with NDs and mitochondria are considered a potential treatment target for NDs. Several obstacles, including the blood-brain barrier (BBB) and cell/mitochondrial membranes, reduce the efficiency of drug entry into the target lesions. Therefore, a variety of neuron mitochondrial targeting strategies has been developed. Among them, nanotechnology-based treatments show especially promising results. Owing to their adjustable size, appropriate charge, and lipophilic surface, nanoparticles (NPs) are the ideal theranostic system for crossing the BBB and targeting the neuronal mitochondria. In this review, we discussed the role of dysfunctional mitochondria in ND pathogenesis as well as the physiological barriers to various treatment strategies. We also reviewed the use and advantages of various NPs (including organic, inorganic, and biological membrane-coated NPs) for the treatment and diagnosis of NDs. Finally, we summarized the evidence and possible use for the promising role of NP-based theranostic systems in the treatment of mitochondrial dysfunction-related NDs.

Enhancing Cancer Immunotherapeutic Efficacy with Sonotheranostic Strategies

Immunotherapy has revolutionized the modality for establishing a firm immune response and immunological memory. However, intrinsic limitations of conventional low responsive poor T cell infiltration and immune related adverse effects urge the coupling of cancer nanomedicines with immunotherapy for boosting antitumor response under ultrasound (US) sensitization to mimic dose-limiting toxicities for safe and effective therapy against advanced cancer. US is composed of high-frequency sound waves that mediate targeted spatiotemporal control over release and internalization of the drug. The unconventional US triggered immunogenic nanoengineered arena assists the limited immunogenic dose, limiting toxicities and efficacies. In this Review, we discuss current prospects of enhanced immunotherapy using nanomedicine under US. We highlight how nanotechnology designs and incorporates nanomedicines for the reprogramming of systematic immunity in the tumor microenvironment. We also emphasize the mechanical and biological potential of US, encompassing sonosensitizer activation for enhanced immunotherapeutic efficacies. Finally, the smartly converging combinational platform of US stimulated cancer nanomedicines for amending immunotherapy is summarized. This Review will widen scientists' ability to explore and understand the limiting factors for combating cancer in a precisely customized way.

Deliver protein across bio-barriers via hexa-histidine metal assemblies for therapy: a case in corneal neovascularization model

Because of their high specificity and low side effects, protein drugs possess a substantial global market. However, the low bioavailability of protein is still a major obstacle to their expanded applications, which is expected to be answered with proper protein formulations. Taking corneal neovascularization (CNV) as an example, we demonstrated a co-assembled system of hexa-histidine and Ava (Avastin) with metal ions (HmA@Ava) could cross the cornea, the most important bio-barrier during the treatment of most diseases of the anterior segment in clinics. We found that the nanosized HmA@Ava efficiently encapsulated Ava with impressive loading capacity without destroying the bioactivity of Ava and assisted Ava penetration through the corneal barriers to effectively inhibit CNV development in an alkali burn rat model with sustained and pH-dependent Ava release. Our results suggested that the co-assembled strategy of protein and HmA is a proper formulation to protein drugs, with promising penetration ability to deliver protein across bio-barriers, which could open a path for topical administration of protein drugs for treatment of various ocular diseases and hold enormous potential for delivery of therapeutic proteins not only for ocular diseases but also for other diseases that require protein treatment.

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HmA@Ava can bring protein drug, Ava, across over the primary bio-barrier of the anterior segment ​and efficiently treat CNV.

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HmA@Ava was nanoparticles, with impressive loading capacity without destroying bioactivity of Ava ​and strong pH-dependent release.

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HmA can open a path for the treatment of eye diseases and hold huge potential to protein drugs to other diseases.

An investigation of alkaline phosphatase enzymatic activity after electrospinning and electrospraying

The high target specificity and multifunctionality of proteins has led to great interest in their clinical use. To this end, the development of delivery systems capable of preserving their bioactivity and improving bioavailability is pivotal to achieve high effectiveness and satisfactory therapeutic outcomes. Electrohydrodynamic (EHD) techniques, namely electrospinning and electrospraying, have been widely explored for protein encapsulation and delivery. In this work, monoaxial and coaxial electrospinning and electrospraying were used to encapsulate alkaline phosphatase (ALP) into poly(ethylene oxide) fibres and particles, respectively, and the effects of the processing techniques on the integrity and bioactivity of the enzyme were assessed. A full morphological and physicochemical characterisation of the blend and core-shell products was performed. ALP was successfully encapsulated within monolithic and core-shell electrospun fibres and electrosprayed particles, with drug loadings and encapsulation efficiencies of up to 21% and 99%, respectively. Monoaxial and coaxial electrospinning were equally effective in preserving ALP function, leading to no activity loss compared to fresh aqueous solutions of the enzyme. While the same result was observed for monoaxial electrospraying, coaxial electrospraying of ALP caused a 40% reduction in its bioactivity, which was attributed to the high voltage (22.5 kV) used during processing. This demonstrates that choosing between blend and coaxial EHD processing for protein encapsulation is not always straightforward, being highly dependent on the chosen therapeutic agent and the effects of the processing conditions on its bioactivity.

Design of metal-organic framework composites in anti-cancer therapies

Metal-organic frameworks are a class of new and promising anti-cancer materials. MOFs with adjustable pore size, large specific surface area, diverse structure, and excellent chemical and physical properties make them a class of effective protection carriers for anti-cancer substances. This review is centered on the core point of "anti-cancer" and discusses MOFs' research progress in anti-cancer therapies. Firstly, we provided readers with the different types of MOFs, their preparation strategies and the resulting structures. Then, different MOF composites and their biological applications were systematically presented. The specificity of biomolecules endows MOFs with broader anti-cancer applications, while MOFs can protect the drugs and biomolecules to make the best of a challenging situation. Finally, we elucidated a comprehensive overview of the biological applications of MOFs, including research hotspots as drug delivery and biomolecule carriers. Besides, we looked forward to the future developments of MOFs in the field of anti-cancer therapies. As a class of novel materials, the anti-cancer applications of MOFs are extended through the combination of different materials and different methods to improve their efficacy.

Self-Assembling Peptides and Carbon Nanomaterials Join Forces for Innovative Biomedical Applications

Self-assembling peptides and carbon nanomaterials have attracted great interest for their respective potential to bring innovation in the biomedical field. Combination of these two types of building blocks is not trivial in light of their very different physico-chemical properties, yet great progress has been made over the years at the interface between these two research areas. This concise review will analyze the latest developments at the forefront of research that combines self-assembling peptides with carbon nanostructures for biological use. Applications span from tissue regeneration, to biosensing and imaging, and bioelectronics.

Anti-inflammation biomaterial platforms for chronic wound healing

Nowadays, there has been an increase in the number of people with chronic wounds, which has resulted in serious health problems worldwide. The rate-limiting stage of chronic wound healing has been found to be the inflammation stage, and strategies for shortening the prolonged inflammatory response have proven to be effective for increasing the healing rate. Recently, various anti-inflammatory strategies (such as anti-inflammatory drugs, antioxidant, NO regulation, antibacterial, immune regulation and angiogenesis) have attracted attention as potential therapeutic pathways. Moreover, various biomaterial platforms based on anti-inflammation therapy strategies have also emerged in the spotlight as potential therapies to accelerate the repair of chronic wounds. In this review, we systematically investigated the advances of various biomaterial platforms based on anti-inflammation strategies for chronic wound healing, to provide valuable guidance for future breakthroughs in chronic wound treatment.

Bioinspired zwitterionic polyphosphoester modified porous silicon nanoparticles for efficient oral insulin delivery

The intestinal epithelial and mucus barriers on the gastrointestinal tract limit the bioavailability of oral protein or peptide drugs. Therefore, efficient mucus permeability and cellular internalization are required properties for oral delivery systems. To overcome these two obstacles, porous silicon nanoparticles were modified with poly (pyridyl disulfide ethylene phosphate/sulfobetaine) polymers to make P(PyEP-g-SBm)n-AmPSiNPs (m = 0.1, 0.2, 0.3 and n = 10, 20, 30) nanoparticles (NPs). The insulin-loaded P(PyEP-g-SB)-AmPSiNPs showed favorable stability and good biocompatibility in vitro. The zwitterionic dodecyl sulfobetaine (SB) coated nanoparticles improved the mucus permeability. P(PyEP-g-SBm)20 with the optimal conjugated ratio (m = 0.3) of SB units was determined by evaluating the mucus diffusion rate of NPs. The cellular uptake of P(PyEP-g-SB0.3)n-AmPSiNPs (n = 10, 20, 30) was much higher than AmPSiNPs in the presence of inhibitors (N-acetylcysteine solution and sodium chlorate) (p < 0.01) due to the enhanced charge shielding effect of P(PyEP-g-SB) modification. The P(PyEP-g-SB0.3)20-AmPSiNPs showed about 1.4-1.7 fold increase in the apparent permeability of insulin across Caco-2/HT-29-MTX cell monolayers, compared to AmPSiNPs (p < 0.01). Finally, the in vivo study showed that insulin-loaded P(PyEP-g-SB0.3)20-AmPSiNPs generated 20% reduction of the blood glucose level with an 2-fold increase in oral bioavailability. These suggested that zwitterionic polyphosphoester modified porous silicon nanoparticles, which were of enhanced mucus permeability and cellular internalization, represent a promising carrier for oral delivery of peptide and protein.

Sustained Release Systems for Delivery of Therapeutic Peptide/Protein

Peptide/protein therapeutics have been significantly applied in the clinical treatment of various diseases such as cancer, diabetes, etc. owing to their high biocompatibility, specificity, and therapeutic efficacy. However, due to their immunogenicity, instability stemming from its complex tertiary and quaternary structure, vulnerability to enzyme degradation, and rapid renal clearance, the clinical application of protein/peptide therapeutics is significantly confined. Though nanotechnology has been demonstrated to prevent enzyme degradation of the protein therapeutics and thus enhance the half-life, issues such as initial burst release and uncontrollable release kinetics are still unsolved. Moreover, the traditional administration method results in poor patient compliance, limiting the clinical application of protein/peptide therapeutics. Exploiting the sustained-release formulations for more controllable delivery of protein/peptide therapeutics to decrease the frequency of injection and enhance patient compliance is thus greatly meaningful. In this review, we comprehensively summarize the substantial advancements of protein/peptide sustained-release systems in the past decades. In addition, the advantages and disadvantages of all these sustained-release systems in clinical application together with their future challenges are also discussed in this review.

Recent advances in microfluidic-aided chitosan-based multifunctional materials for biomedical applications

Chitosan-based biomaterials has shown great advantages in a broad range of applications, including drug delivery, clinical diagnosis, cell culture and tissue engineering. However, due to the lack of control over the fabrication processes by conventional techniques, the wide application of chitosan-based biomaterials has been hampered. Recently, microfluidics has been demonstrated as one of the most promising platforms to fabricate high-performance chitosan-based multifunctional materials with monodisperse size distribution and accurately controlled morphology and microstructures, which show great promising for biomedical applications. Here, we review recent progress of the fabrication of chitosan-based biomaterials with different structures and integrated functions by microfluidic technology. A comprehensive and in-depth depiction of critical microfluidic formation mechanism and process of various chitosan-based materials are first interpreted, with particular descriptions about the microfluidic-mediated control over the morphology and microstructures. Afterwards, recently emerging representative applications of chitosan-based multifunctional materials in various fields, are systematically summarized. Finally, the conclusions and perspectives on further advancing the microfluidic-aided chitosan-based multifunctional materials toward potential and versatile development for fundamental researches and biomedicine are proposed.

Chitosan Coated Luteolin Nanostructured Lipid Carriers: Optimization, In Vitro-Ex Vivo Assessments and Cytotoxicity Study in Breast Cancer Cells

In the present study, luteolin (LTN)-encapsulated chitosan (CS) coated nanostructured lipid carriers (NLCs) were formulated using the melt emulsification ultrasonication technique. NLCs were optimized by using the 33-QbD approach for improved in vitro efficacy against breast cancer cell lines. The optimized LTN-CS-NLCs were successfully characterized by different in vitro and ex vivo experiments as well as evaluated for cytotoxicity in MDA-MB-231 and MCF-7 cell lines. The prepared LTN-CS-NLCs showed particle size (PS), polydispersity index (PDI), and entrapment efficiency (%EE) in the range between 101.25 nm and 158.04 nm, 0.11 and 0.20, and 65.55% and 95.37%, respectively. Coating of NLCs with CS significantly increased the particle size, encapsulation efficiency, and zeta potential changes positively. Moreover, slow-release rate of LTN was achieved during 24 h of study for LTN-CS-NLCs. In addition, optimized LTN-CS-NLCs showed significantly higher mucoadhesion, gastrointestinal stability, and intestinal permeation compared to non-coated LTN-NLCs and LTN suspension. Furthermore, LTN-CS-NLCs showed statistically enhanced antioxidant potential as well as dose and time-dependent cytotoxicity against MDA-MB-231 and MCF-7 cells compared to uncoated LTN-NLCs and pure LTN. On the basis of the above findings, it may be stated that chitosan-coated LTN-NLCs represents a great potential for breast cancer management.