Hydrophilic Peptides Research Articles

Polysaccharides: New Frontiers for Nasal Administration of Medicines

The nasal cavity has become a focal point for drug delivery research. Beyond its use in treating local diseases, the nasal route is appealing due its ability to deliver systemically potent drugs with low oral bioavailability. Recent interest in nasal vaccination has driven significant pre-clinical and clinical advancements. Further R&D holds promise for expanding nasal medications, offering innovative healthcare solutions. This review explores strategies using polysaccharides to enhance nasal delivery of hydrophilic drugs, peptides, proteins, genes, and other active compounds that typically struggle to permeate the nasal epithelium. Polysaccharides are attractive excipients due to their potential to enhance nasal absorption, regulate drug release, and extend residence time in the nasal cavity through bioadhesive properties. Studies on their mechanisms affecting drug absorption, potential toxicities, and applications will also be reviewed considering the particularities of nasal epithelium anatomy and physiology. Most products with these excipients are in pre-clinical and clinical evaluation, but PecFent, a pectin-based formulation, is approved for nasal administration of opioids for breakthrough cancer pain, offering faster pain relief and a better benefit–risk ratio due to pectin. Other polysaccharides like chitosan, cyclodextrins, hyaluronic acid, and alginate have shown potential in enhancing nasal drug absorption. This approach also holds promise for enhancing drug transport from the nasal cavity to the CNS (nose-to-brain), potentially advancing treatments for neurodegenerative diseases.

A Streamlined High-Throughput LC-MS Assay for Quantifying Peptide Degradation in Cell Culture.

Peptides are widely used in biomaterials due to their ease of synthesis, ability to signal cells, and modify the properties of biomaterials. A key benefit of using peptides is that they are natural substrates for cell-secreted enzymes, which creates the possibility of utilizing cell-secreted enzymes for tuning cell-material interactions. However, these enzymes can also induce unwanted degradation of bioactive peptides in biomaterials, or in peptide therapies. Liquid chromatography-mass spectrometry (LC-MS) is a widely used, powerful methodology that can separate complex mixtures of molecules and quantify numerous analytes within a single run. There are several challenges in using LC-MS for the multiplexed quantification of cell-induced peptide degradation, including the need for nondegradable internal standards and the identification of optimal sample storage conditions. Another problem is that cell culture media and biological samples typically contain both proteins and lipids that can accumulate on chromatography columns and degrade their performance. Removing these constituents can be expensive, time-consuming, and increases sample variability. However, loading unpurified samples onto the column without removing lipids and proteins will foul the column. Here, we show that directly injecting complex, unpurified samples onto the LC-MS without any purification enables rapid and accurate quantification of peptide concentration and that hundreds of LC-MS runs can be done on a single column without significantly diminishing the ability to quantify the degradation of peptide libraries. To understand how repeated injections degrade column performance, a model library was injected into the LC-MS hundreds of times. It was then determined that column failure is evident when hydrophilic peptides are no longer retained on the column and that failure can be easily identified by using standard peptide mixtures for column benchmarking. In total, this work introduces a simple and effective method for simultaneously quantifying the degradation of dozens of peptides in cell culture. By providing a streamlined and cost-effective method for the direct quantification of peptide degradation in complex biological samples, this work enables more efficient assessment of peptide stability and functionality, facilitating the development of advanced biomaterials and peptide-based therapies.

Preparation and identification novel angiotensin-converting enzyme-inhibitory peptides derived from fish waste

The purpose of the research is to compare short peptides from different hydrolysates of fish entrails that can inhibit the activity of angiotensin-converting enzyme (ACE). Fish hydrolysates derived from Catfish, Tilapia, and Mackerel entrails were digested by pepsin and passed through the 3kDa cutoff column. The fraction containing peptides shorter than and equal to 3kDa from catfish hydrolysate has the great ability to inhibit ACE activity in converting the substrate (Furanacroloy-Phe-Gly-Gly, FAPGG) and producing FAP and GG as the products of the reaction. The 3kDa filtrate from the catfish hydrolysate had activity like Captopril, a drug for treating hypertension. The 3kDa filtrate derived from the catfish entrail hydrolysate was purified using OFFGEL electrophoresis and then passed through the C18 column. The 3kDa filtrate was separated into two fractions and then these fractions were determined ACE inhibitory activity. The result showed that the fractions containing hydrophilic peptides and others containing hydrophobic peptides possessed inhibitory activity against ACE. Those fractions were analyzed with LCMS/MS for sequencing. The results revealed that synthesized peptides; ASNLHGV, LFKDLR, PGYALQR, and LETAKSR, derived from the catfish hydrolysate showed anti-ACE activity against its substrate.

Chitosan ‘s role in enhancing nasal drug absorption

The nasal drug delivery system (NDDS) offers a promising route for the administration of therapeutically active compounds, particularly for those requiring rapid onset of action or bypassing the first-pass metabolism. The system provides a direct pathway to the bloodstream, enhancing bioavailability and enabling effective treatment of both local and systemic conditions. Among various enhancement strategies, chitosan, a biopolymer derived from the exoskeletons of crustaceans, has garnered attention as a potent nasal absorption enhancer. Its mucoadhesive properties and ability to temporarily open tight junctions in the nasal epithelium allow for improved drug permeation, particularly for hydrophilic drugs, peptides, and macromolecules. This research focuses on the extraction, characterization, and application of chitosan derived from crab and prawn shells to formulate an effective nasal drug delivery system, particularly for the treatment of migraines. The study aims to develop a nasal spray formulation containing sumatriptan Succinate commonly used migraine medication, to enhance its absorption through the nasal mucosa. The role of chitosan in improving the bioavailability and targeting of drugs to the brain is examined, alongside its biocompatibility and safety profile. Through various in-vitro and ex-vivo studies, the pharmacokinetics, pharmacodynamics, and toxicity of the chitosan-based nasal formulation are evaluated. The findings suggest that chitosan enhances the therapeutic potential of nasal drug delivery systems, providing faster relief with improved drug absorption. This study underscores the potential of natural polysaccharides in revolutionizing drug delivery technologies and improving patient outcomes.

Recent Innovations and Future Perspectives in Transferosomes for Transdermal Drug Delivery in Therapeutic and Pharmacological Applications.

There have been several non-invasive administrations that have emerged recently to replace conventional needle injections. With its minimal rejection rate, remarkable ease of administration, and remarkable patient comfort and perseverance, the transdermal drug delivery system (TDDS) is the most attractive of them all. The skincare industry, which includes cosmetics, may also find use for TDDS in addition to the pharmaceutical industry. As this strategy mainly entails local drug administration, it can prevent untargeted drug delivery to tissues not intended for the treatment and buildup of localized drug concentrations. Transdermal delivery is hampered by a number of physicochemical characteristics of the skin, which have led to a great deal of research into ways to get over these barriers. The majority of transdermal medicines that have proved effective do so by using smaller lipophilic compounds, which have a molecular weight of a few 100 Daltons. Transferosomes have proven to be an effective method for transdermal distribution of a range of therapies, including hydrophilic actives, bigger molecules, peptides, proteins, and nucleic acids, in order to get around the medications' size and lipophilicity limits. Because of their flexible form and increased surface hydrophilicity, transferosomes are essential for the delivery of medicines and other solutes through and into the skin by exploiting hydration gradients a source of energy. As a result, the medication is released into the skin layers under regulated conditions and has improved overall penetration. In this section we outline the development of transferosomes from liposomes and solid lipid nanoparticles, as well as their subsequent advancements as commercially available dosage forms, physical-chemical characteristics, and cutaneous kinetics.

Synergistically Activated Aggregation-Induced Emission Probe for Precise In Situ Staining of Lipids in Atherosclerotic Plaques.

Visualizing the localization and distribution of lipids within arteries is crucial for studying atherosclerosis. However, existing lipid-specific probes face challenges such as strong hydrophobicity and nonspecific staining of lipophilic organelles or tissues, making them impractical for the precise identification of atherosclerotic plaques. To address this issue, we design a synergistically activated probe, Cbz-Lys-Lys-TPEB, which responds to cathepsin B (CTB) and H2O2 for the in situ generation of aggregation-induced emission luminogens (AIEgens). This enables specific staining of lipids within arteries and precise imaging of atherosclerotic plaques. The probe combines a tetraphenylethene building block with a hydrophilic peptide sequence (Cbz-Lys-Lys) and phenylboric acid module, providing excellent water solubility and fluorescence quenching in a molecular dispersion state. Upon interaction with H2O2 and CTB within plaques, the hydrophilic Cbz-Lys-Lys-TPEB probe is specifically cleaved and converted into hydrophobic AIEgens, leading to rapid aggregation and significant fluorescence enhancement. Interestingly, the in situ-liberated AIEgens display distinct lipid binding ability, effectively tracking the location and distribution of lipids in plaques. This synergistic target-activated AIEgen liberation strategy demonstrates significant feasibility for the reliable and accurate identification of atherosclerotic plaques, holding tremendous potential for clinical diagnosis and risk stratification of atherosclerosis.

Effect of peptide hydrophilicity on membrane curvature and permeation.

Using a well-developed reaction coordinate in umbrella sampling, we studied the single peptide permeation through a model cancerous cell membrane, varying the hydrophilicity and the charge of the peptides. Two peptides, melittin and pHD108, were studied. The permeation mechanism differs from a barrel-stave-like mechanism to toroidal pore and vesicle formation based on the number and the placement of the hydrophilic amino acids in the peptide. Membrane curvature changes dynamically as the permeation process occurs. In the case of vesicles, the peptide traverses along a smooth, homogenous pathway, whereas a rugged, steep pathway was found when lipid molecules did not line up along the wall of the membrane (barrel-stave-like mechanism). A mechanism similar to a toroidal pore consists of multiple minima. Higher free energy was found for the permeating terminal containing charged amino acid residues. Vesicle formation was found for pHD108 peptide N-terminal with a maximum membrane thinning effect of 54.4% with free energy cost of 8.20 ± 0.10kcal mol-1 and pore radius of 2.33 ± 0.07nm. Insights gained from this study can help to build synthetic peptides for drug delivery.

A Streamlined High-Throughput LC-MS Assay for Quantifying Peptide Degradation in Cell Culture.

Peptides are widely used in biomaterials due to their easy of synthesis, ability to signal cells, and modify the properties of biomaterials. A key benefit of using peptides is that they are natural substrates for cell-secreted enzymes, which creates the possibility of utilizing cell-secreted enzymes for tuning cell-material interactions. However, these enzymes can also induce unwanted degradation of bioactive peptides in biomaterials, or in peptide therapies. Liquid chromatography-mass spectrometry (LC-MS) is a widely used, powerful methodology that can separate complex mixtures of molecules and quantify numerous analytes within a single run. There are several challenges in using LC-MS for the multiplexed quantification of cell-induced peptide degradation, including the need for non-degradable internal standards and the identification of optimal sample storage conditions. Another problem is that cell culture media and biological samples typically contain both proteins and lipids that can accumulate on chromatography columns and degrade their performance. However, removing these constituents can be expensive, time consuming, and increases sample variability. Here we show that directly injecting samples onto the LC-MS without any purification enables rapid and accurate quantification of peptide concentration, and that hundreds of LC-MS runs can be done on a single column without a significantly diminish the ability to quantify the degradation of peptide libraries. We also show that column failure is evident when hydrophilic peptides fail to be retained on the column, and this can be easily identified using standard peptide mixtures for column benchmarking. In total, this work introduces a simple and effective method for simultaneously quantifying the degradation of dozens of peptides in cell culture. By providing a streamlined and cost-effective method for the direct quantification of peptide degradation in complex biological samples, this work enables more efficient assessment of peptide stability and functionality, facilitating the development of advanced biomaterials and peptide-based therapies.

Strategic Design of Tryptophan-Aspartic Acid-Containing Peptide Inhibitors Using Coronin 1 as a Template: Inhibition of Fusion by Enhancing Acyl Chain Order.

Enveloped viruses enter the host cell by fusing at the cell membrane or entering the cell via endocytosis and fusing at the endosome. Conventional inhibitors target the viral fusion protein to inactivate it for inducing fusion. These target-specific vis-à-vis virus-specific inhibitors fail to display their inhibitory efficacy against emerging and remerging viral infections. This necessitates the need to develop broad-spectrum entry inhibitors that are effective irrespective of the virus. Using a broad range of targeting techniques, the fusion inhibitors can modify the physical characteristics of the viral membrane, making it less prone to fusion. We have previously shown that two tryptophan-aspartic acid (WD)-containing hydrophobic peptides, TG-23 and GG-21, from coronin 1, a phagosomal protein, inhibit membrane fusion by modulating membrane organization and dynamics. In the present work, we designed two WD-containing hydrophilic peptides, QG-22 and AG-22, using coronin 1 as a template and evaluated their fusion inhibitory efficacies in the absence and presence of membrane cholesterol. Our results demonstrate that QG-22 and AG-22 inhibit membrane fusion irrespective of the concentration of membrane cholesterol. Our measurements of depth-dependent membrane organization and dynamics reveal that they impede fusion by enhancing the acyl chain order. Overall, our results validate the hypothesis of designing fusion inhibitors by modulating the membrane's physical properties. In addition, it demonstrates that chain hydrophobicity might not be a critical determinant for the development of peptide-based fusion inhibitors.

Air-water interfacial and foaming properties of nanoparticles based on commercial and lab-scale isolated maize (Zea mays L.) zein

Maize zein based nanoparticles (ZNPs) can have applications as food dispersion stabilizers. It has not been documented to what extent the used zein isolation method and conditions thereof impact the structure and functionality of nanoparticles (NPs) based thereupon. Here, zein extracted from maize flour on lab scale (LS-zein) was compared with a commercial zein powder (CS-zein). On a dry matter basis, CS-zein contained 96.5% protein, while LS-zein contained 74.5% protein, 12.7% lipid, 2.9% ash, and a residual fraction, likely starch remnants. SE-HPLC analysis showed that 27.8% of CS-zein protein occurred in an aggregated and insoluble form, while LS-zein mainly contained mono-/dimeric proteins but also approximately 30% hydrophilic peptides. These differences resulted in notably different behavior in the functionality of ZNPs based on CS- and LS-zein (CS-ZNPs and LS-ZNPs, respectively) produced via liquid antisolvent precipitation. CS-ZNPs had poor foaming properties regardless of the pH, in line with their low interfacial dilatational moduli (12.9–15.0 mN/m). The foaming properties of LS-ZNPs were notably better. The high LS-ZNP foam stability (FS) at pH 8.0 and 10.0 was attributed to electrostatic repulsive effects between interfaces of adjacent air bubbles due to the adsorption of peptides and to synergistic protein-lipid interaction effects at the air–water interface. The LS-ZNP FS at pH 4.0 was low despite a high interfacial dilatational modulus (52.6 mN/m). It is hypothesized that intact LS-ZNPs in the liquid thin films between gas bubbles negatively affect FS by a bridging de-wetting effect. Overall, it can be concluded that the (partial) co-isolation of lipids with zein may positively influence foaming properties of NPs based thereupon, while extensive zein purification as applied in industrial zein isolation leads to (partial) zein aggregation and overall low foaming capacity of the obtained CS-ZNPs.

Electromembrane extraction of peptides based on charge, hydrophobicity, and size - A large-scale fundamental study of the extraction window.

This study investigated the capability of electromembrane extraction (EME) as a general technique for peptides, by extracting complex pools of peptides comprising in total of 5953 different substances, varying in size from seven to 16 amino acids. Electromembrane extraction was conducted from a sample adjusted to pH 3.0 and utilized a liquid membrane consisting of 2-nitrophenyl octyl ether and carvacrol (1:1 w/w), containing 2% (w/w) di(2-ethylhexyl) phosphate. The acceptor phase was 50mM phosphoric acid (pH 1.8), the extraction time was 45 min, and 10 V was used. High extraction efficiency, defined as a higher peptide signal in the acceptor than the sample after extraction, was achieved for 3706 different peptides. Extraction efficiencies were predominantly influenced by the hydrophobicity of the peptides and their net charge in the sample. Hydrophobic peptides were extracted with a net charge of +1, while hydrophilic peptides were extracted when the net charge was +2 or higher. A computational model based on machine learning was developed to predict the extractability of peptides based on peptide descriptors, including the grand average of hydropathy index and net charge at pH 3.0 (sample pH). This research shows that EME has general applicability for peptides and represents the first steps toward in silico prediction of extraction efficiency.

Membrane Disruption-Enhanced Photodynamic Therapy against Gram-Negative Bacteria by a Peptide-Photosensitizer Conjugate.

Photodynamic therapy (PDT) emerges as a promising strategy for combating bacteria with minimal drug resistance. However, a significant hurdle lies in the ineffectiveness of most photosensitizers against Gram-negative bacteria, primarily attributable to their characteristic impermeable outer membrane (OM) barrier. To tackle this obstacle, we herein report an amphipathic peptide-photosensitizer conjugate (PPC) with intrinsic outer membrane disruption capability to enhance PDT efficiency against Gram-negative bacteria. PPC is constructed by conjugating a hydrophilic ultrashort cationic peptide to a hydrophobic photosensitizer. PPC could efficiently bind to the OM of Gram-negative bacteria through electrostatic adsorption, and subsequently disrupt the structural integrity of the OM. Mechanistic investigations revealed that PPC triggers membrane disruption by binding to both lipopolysaccharide (LPS) and phospholipid leaflet in the OM, enabling effective penetration of PPC into the Gram-negative bacteria interior. Upon light irradiation, PPC inside bacteria generates singlet oxygen not only to effectively decrease the survival of Gram-negative bacteria P. aeruginosa and E. coli to nearly zero in vitro, but also successfully cure the full-thickness skin infection and bacterial keratitis (BK) induced by P. aeruginosa in animal models. Thus, this study provides a broad-spectrum antibacterial phototherapeutic design strategy by the synergistic action of membrane disruption and PDT to combat Gram-negative bacteria.

Targeted delivery of activatable 131I-radiopharmaceutical for sustained radiotherapy with improved pharmacokinetics

Targeted radionuclide therapy (TRT) is an effective treatment for tumors. Self-condensation strategies can enhance the retention of radionuclides in tumors and enhance the anti-tumor effect. Considering legumain is overexpressed in multiple types of human cancers, a 131I-labeled radiopharmaceutical ([131I]MAAN) based on the self-condensation reaction between 2-cyanobenzothiazole (CBT) and cysteine (Cys) was developed by us recently for treating legumain-overexpressed tumors. However, liver enrichment limits its application. In this study, a new radiopharmaceutical [131I]IM(HE)3AAN was designed and synthesized by introducing a hydrophilic peptide sequence His-Glu-His-Glu-His-Glu ((HE)3) into [131I]MAAN to optimize the pharmacokinetics. Upon activation by legumain under a reducing environment, hydrophilic [131I]IM(HE)3AAN could react with its precursor to form heterologous dimer [131I]H-Dimer that is highly hydrophobic. Cerenkov imaging revealed that [131I]IM(HE)3AAN displayed superior tumor selectivity and longer tumor retention time as compared with [131I]MAAN, with a significant reduction in the liver uptake. After an 18-day treatment with [131I]IM(HE)3AAN, the tumor proliferation was obviously inhibited, while no obvious injury was observed in the normal organs. These findings suggest that [131I]IM(HE)3AAN could serve as a promising drug candidate for treating legumain-overexpressed tumors.

Nucleus-targeting Oxaplatin(IV) prodrug Amphiphile for enhanced chemotherapy and immunotherapy

Platinum(II)-based drugs (PtII), which hinder DNA replication, are the most widely used chemotherapeutics. However, current PtII drugs often miss their DNA targets, leading to severe side effects and drug resistance. To overcome this challenge, we developed a oxaliplatin-based platinum(IV) (PtIV) prodrug amphiphile (C16-OPtIV-R8K), integrating a long-chain hydrophobic lipid and a nucleus-targeting hydrophilic peptide (R8K). This design allows the prodrug to self-assemble into highly uniform lipid nanoparticles (NTPtIV) for enhanced targeting chemotherapy and immunotherapy. Subsequently, NTPtIV's bioactivity and effects were examined at diverse levels, encompassing cancer cells, 3D tumor spheres, and in vivo. Our in vitro studies show a 74% cancer cell nucleus localization of platinum drugs-3.6 times higher than that of oxaliplatin, achieving more than a ten-fold increase in eliminating drug-resistant cancer cells. In vivo, NTPtIV shows efficient tumor accumulation, leading to suppressed tumor growth of murine breast cancer. Moreover, NTPtIV recruited more CD4+ and CD8+ T cells and reduced CD4+ Foxp3+ Tregs to synergistically enhance targeted chemotherapy and immunotherapy. Overall, this strategy presents a promising advancement in nucleus-targeted cancer therapy, synergistically boosting the efficacy of chemotherapy and immunotherapy.

Dual electro-/pH-responsive nanoparticle/hydrogel system for controlled delivery of anticancer peptide

An electro-chemo-responsive carrier has been engineered for the controlled release of a highly hydrophilic anticancer peptide, CR(NMe)EKA (Cys-Arg- N-methyl-Glu-Lys-Ala). Remotely controlled on demand release of CR(NMe)EKA, loaded in electro-responsive poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles, has been achieved by applying electrical stimuli consisting of constant positive (+0.50 V) or negative voltages (−0.50 V) at pre-defined time intervals. In addition, after loading CR(NMe)EKA/PEDOT nanoparticles into an injectable pH responsive hydrogel formed by phenylboronic acid grafted to chitosan (PBA-CS), the efficiency of the controlled peptide release has increased approximately by a factor of 2.6. The hydration ratio of such hydrogel is significantly lower in acidic environments than in neutral and basic media, which has been attributed to the dissociation of the boronate bonds between polymer chains. Hence, the electro-controlled peptide release from PBA-CS/CR(NMe)EKA/PEDOT hydrogels, in the acidic environment of tumors, combines the effects of the oxidation and reduction of PEDOT chains on the interactions with the peptide and the carrier, with the peptide concentration gradient at the interface between the collapsed hydrogel and the release medium. Furthermore, the peptide released by electro-stimulation preserved its bioactivity assessed by promoting human prostate cancer cells death. Overall, this work is a promising attempt to develop a carrier platform for small hydrophilic anticancer peptides, which delivery rationale is synergistically regulated by the electrical and pH responsiveness of the carrier.

A comparison of the activity, lysosomal stability, and efficacy of legumain-cleavable and cathepsin-cleavable ADC linkers

Over the past two decades, antibody-drug conjugates (ADCs) have emerged as a highly effective drug delivery technology. ADCs utilise a monoclonal antibody, a chemical linker, and a therapeutic payload to selectively deliver highly potent pharmaceutical agents to specific cell types. Challenges such as premature linker cleavage and clearance due to linker hydrophobicity have adversely impacted the stability and safety of ADCs. While there are various solutions to these challenges, our team has focused on replacement of hydrophobic ValCit linkers (cleaved by CatB) with Asn-containing linkers that are cleaved by lysosomal legumain. Legumain is abundantly present in lysosomes and is known to play a role in tumour microenvironment dynamics. Herein, we directly compare the lysosomal cleavage, cytotoxicity, plasma stability, and efficacy of a traditional cathepsin-cleavable ADC to a matched Asn-containing legumain-cleavable ADC. We demonstrate that Asn-containing linker sequences are specifically cleaved by lysosomal legumain and that Asn-linked MMAE ADCs are broadly active against a variety of tumours, even those with low legumain expression. Finally, we show that AsnAsn-linked ADCs exhibit comparable or improved efficacy to traditional ValCit-linked ADCs. Our study paves the way for replacement of the traditional ValCit linker technology with more hydrophilic Asn-containing peptide linker sequences.

Microemulsions and Nanoemulsions for Topical Delivery of Tripeptide-3: From Design of Experiment to Anti-Sebum Efficacy on Facial Skin.

The targeted delivery of a hydrophilic Tripeptide-3 to the skin using microemulsions or nanoemulsions for facial oil reduction was the focus of this study. The impact factors affecting oil/water transparent dispersion formation, such as the surfactant system, HLB value, and co-solvent, were identified through the water titration method and pseudoternary phase diagram plots. The interfacial tension between caprylic/capric triglyceride (CCT oil) and water was significantly reduced by the surfactant/co-surfactant combination (Smix) of Cremophore® RH40 and a double-tails co-surfactant, polyglycerol-3-diisostearate, at an HLB of 13 together with a water-to-co-solvent (PG) ratio of 1:1. A two-level full factorial design of experiment (FFD-DoE) emphasized the independent variables of the HLB value, co-solvent, and CCT oil contents affecting the optimal compositions for micro- or nanoemulsion formation. The low-energy spontaneous emulsification of the optimized combination at a low Smix content (10%) yielded the translucent oil-in-water Tripeptide-3 nanoemulsions with an internal droplet size of 25.7 ± 1.20 nm, a narrow polydispersity index of 0.237 ± 0.129, and 70.6 ± 0.58% transmittance. The in vitro skin permeation study revealed a significantly higher skin penetration and retention of the Tripeptide-3 nanoemulsions compared to the high surfactant microemulsions and coarse emulsions. Skin irritation and oil control efficacy were evaluated in healthy volunteers before and after product application for 28 days. The obtained nanoemulsions not only decreased sebum production but also enhanced skin moisture levels. In conclusion, the meticulously designed nanoemulsions, incorporating suitable excipients, show a promising delivery system for hydrophilic peptides to control sebum overproduction in oily facial skin.

Neat plasma proteomics: getting the best out of the worst

Plasma proteomics holds immense potential for clinical research and biomarker discovery, serving as a non-invasive "liquid biopsy" for tissue sampling. Mass spectrometry (MS)-based proteomics, thanks to improvement in speed and robustness, emerges as an ideal technology for exploring the plasma proteome for its unbiased and highly specific protein identification and quantification. Despite its potential, plasma proteomics is still a challenge due to the vast dynamic range of protein abundance, hindering the detection of less abundant proteins. Different approaches can help overcome this challenge. Conventional depletion methods face limitations in cost, throughput, accuracy, and off-target depletion. Nanoparticle-based enrichment shows promise in compressing dynamic range, but cost remains a constraint. Enrichment strategies for extracellular vesicles (EVs) can enhance plasma proteome coverage dramatically, but current methods are still too laborious for large series. Neat plasma remains popular for its cost-effectiveness, time efficiency, and low volume requirement. We used a test set of 33 plasma samples for all evaluations. Samples were digested using S-Trap and analyzed on Evosep One and nanoElute coupled to a timsTOF Pro using different elution gradients and ion mobility ranges. Data were mainly analyzed using library-free searches using DIA-NN. This study explores ways to improve proteome coverage in neat plasma both in MS data acquisition and MS data analysis. We demonstrate the value of sampling smaller hydrophilic peptides, increasing chromatographic separation, and using library-free searches. Additionally, we introduce the EV boost approach, that leverages on the extracellular vesicle fraction to enhance protein identification in neat plasma samples. Globally, our optimized analysis workflow allows the quantification of over 1000 proteins in neat plasma with a 24SPD throughput. We believe that these considerations can be of help independently of the LC–MS platform used.

Potential Prebiotic Properties of Whey Protein and Glycomacropeptide in Gut Microbiome.

Proteins in whey have prebiotic and antimicrobial properties. Whey protein comprises numerous bioactive proteins and peptides, including glycomacropeptide (GMP), a hydrophilic casein peptide that separates with the whey fraction during cheese making. GMP has traditionally been used as a protein source for individuals with phenylketonuria and also has prebiotic (supporting the growth of Bifidobacterium and lactic acid bacteria) and antimicrobial activities. GMP supplementation may help positively modulate the gut microbiome, help treat dysbiosis-related gastrointestinal disorders and improve overall health in consumers.

Nanogel delivery systems for cationic peptides: More than a ‘One Size Fits All’ solution

Self-assembled hyaluronic acid-based nanogels are versatile drug carriers due to their biodegradable nature and gentle preparation conditions, making them particularly interesting for delivery of peptide therapeutics. This study aims to elucidate the relation between peptide structure and encapsulation in a nanogel. Key peptide properties that affect encapsulation in octenyl succinic anhydride-modified hyaluronic acid nanogels were identified as we explored the effect on nanogel characteristics using 12 peptides with varying charge and hydrophobicity. The size and surface properties of the microfluidics-assembled peptide-loaded nanogels were evaluated using dynamic light scattering, laser Doppler electrophoresis, and small angle neutron scattering. Additionally, the change in peptide secondary structure upon encapsulation in nanogels, their release from the nanogels, and the in vitro antimicrobial activity were assessed. In conclusion, the more hydrophobic peptides showed stronger binding to the nanogel carrier and localized internally rather than on the surface of the nanogel, resulting in more spherical nanogels with smoother surfaces and slower release profiles. In contrast, cationic and hydrophilic peptides localized at the nanogel surface resulting in fluffier nanogel structures and quick and more complete release in biorelevant medium. These findings emphasize that the advantages of nanogel delivery systems for different applications depend on the therapeutic peptide properties.