Enhanced Skin Permeation of Anti-wrinkle Peptides via Molecular Modification

Advances in Transdermal Delivery of Antimicrobial Peptides for Wound Management: Biomaterial-Based Approaches and Future Perspectives

Antimicrobial peptides (AMPs), distinguished by their cationic and amphiphilic nature, represent a critical frontier in the battle against antimicrobial resistance due to their potent antimicrobial activity and a broad spectrum of action. However, the clinical translation of AMPs faces hurdles, including their susceptibility to degradation, limited bioavailability, and the need for targeted delivery. Transdermal delivery has immense potential for optimizing AMP administration for wound management. Leveraging the skin's accessibility and barrier properties, transdermal delivery offers a noninvasive approach that can circumvent systemic side effects and ensure sustained release. Biomaterial-based delivery systems, encompassing nanofibers, hydrogels, nanoparticles, and liposomes, have emerged as key players in enhancing the efficacy of transdermal AMP delivery. These biomaterial carriers not only shield AMPs from enzymatic degradation but also provide controlled release mechanisms, thereby elevating stability and bioavailability. The synergistic interaction between the transdermal approach and biomaterial-facilitated formulations presents a promising strategy to overcome the multifaceted challenges associated with AMP delivery. Integrating advanced technologies and personalized medicine, this convergence allows the reimagining of wound care. This review amalgamates insights to propose a pathway where AMPs, transdermal delivery, and biomaterial innovation harmonize for effective wound management.

Anti-aging activity of Syn-Ake peptide by in silico approaches and in vitro tests

The increase in the aging population worldwide has led scientists to turn to research to prevent the aging process. In this context, synthetic peptides emerge as candidate molecules for developing new anti-aging products. This study aims to investigate the possible interactions of Syn-Ake, a synthetic peptide, with matrix metalloproteinases (MMPs) and Sirtuin 1 (SIRT1), which are the targets of anti-aging activities with in silico approaches, and to determine the antioxidant activity, and safety profile of the peptide by in vitro methods such as cytotoxicity (MTT) and genotoxicity (Ames) tests. The molecular docking study showed that the docking score energy of MMP receptors was in the order of MMP-13 < MMP-8 < MMP-1. Syn-Ake peptide provided the lowest and the most stable binding to the SIRT1 receptor at -9.32 kcal/mol. Binding interaction and protein-ligand stability of Syn-Ake with MMPs and SIRT1 in a dynamic system were predicted by 50 ns molecular dynamic (MD) simulation studies. The MD results showed that the Syn-Ake peptide remained stable in the active site of MMP-13 and SIRT1 receptors during 50 ns simulations. In addition, the antioxidant activity of Syn-Ake was investigated using diphenyl-2-picril-hydrazine (DPPH) method since it is crucial to remove free radicals that are effective in skin aging. The results revealed the concentration-dependent increased DPPH radical scavenging activity of the peptide. Finally, the safety of the Syn-Ake was investigated, and the safe dose of the peptide was determined. In conclusion, in silico and in vitro analyses show that the Syn-Ake peptide may hold promise in anti-aging formulations with its high efficacy and safety profile.Communicated by Ramaswamy H. Sarma.

Enhancing Stability and Albumin Binding Efficiency of α-Conotoxin GI through Fatty Acid Modification

α-Conotoxin GI is a competitive blocker of muscle-type acetylcholine receptors and holds the potential for being developed as a molecular probe or a lead compound for drug discovery. In this study, four fatty acid-modified α-conotoxin GI analogues of different lengths were synthesized by using a fatty acid modification strategy. Then, we performed a series of in vitro stability assays, albumin binding assays, and pharmacological activity assays to evaluate these modified mutants. The experimental results showed that the presence of fatty acids significantly enhanced the in vitro stability and albumin binding ability of α-conotoxin GI and that this effect was proportional to the length of the fatty acids used. Pharmacological activity tests showed that the modified mutants maintained a good acetylcholine receptor antagonistic activity. The present study shows that fatty acid modification can be an effective strategy to significantly improve conotoxin stability and albumin binding efficiency while maintaining the original targeting ion channel activity.

Peptide-containing nanoformulations: Skin barrier penetration and activity contribution

Transdermal drug delivery presents a less invasive pathway, circumventing the need to pass through the gastrointestinal tract and liver, thereby reducing drug breakdown, initial metabolism, and gastrointestinal discomfort. Nevertheless, the unique composition and dense structure of the stratum corneum present a significant barrier to transdermal delivery. This article presents an overview of the current developments in peptides and nanotechnology to address this challenge. Initially, we sum up peptide-containing nanoformulations for transdermal drug delivery, examining them through the lenses of both inorganic and organic materials. Particular emphasis is placed on the diverse roles that peptides play within these nanoformulations, including conferring functionality upon nanocarriers and enhancing the biological efficacy of drugs. Subsequently, we summarize innovative strategies for enhancing skin penetration, categorizing them into passive and active approaches. Lastly, we discuss the therapeutic potential of peptide-containing nanoformulations in addressing a range of diseases, drawing insights from the biological activities and functions of peptides. Furthermore, the challenges hindering clinical translation are also discussed, providing valuable insights for future advancements in transdermal drug delivery.

Investigating the effects of Argireline in a skin serum containing hyaluronic acids on skin surface wrinkles using the Visia® Complexion Analysis camera system for objective skin analysis

Objective

To analyze the effects of Argireline on skin surface wrinkles using the Visia® camera system developed by Canfield Scientific Inc., U.S.A., for facial image capture.

Method

Nineteen female participants were recruited from a plastic surgery clinic. Initial facial images captured the left, front, and right sides of the participants' faces, which were documented as timepoint one. Following this, the participants immediately began to apply a facial skin serum containing triple hyaluronic acids produced by CNC cosmetic GmbH, Philippsburg, Germany. The serum was applied once in the morning and once in the evening. Participants received two identical containers labeled L for left and R for right, with each container to be used on the corresponding facial side, particularly around the eye area. One container contained Argireline, a synthetic hexapeptide, which previously was deemed to be a biosafe alternative to botulinum neurotoxin. The study was conducted as double-blind; neither the participants nor researchers knew which of the two containers contained Argireline. Participants were allowed to use their own cosmetic products throughout the study. After four weeks, the participants returned to have their faces recaptured using the Visia® camera, which was documented as timepoint two. The absolute scores of the wrinkles were noted, and results on both sides of the face were calculated and compared. The "TruSkinAge®" measurement provided by the Visia® camera was reviewed for each face side. Results between both time points and both sides of the face were compared. After the data analysis was complete, the company was contacted to determine which container contained Argireline.

Results

Nineteen participants returned for facial image capture. There were no significant adverse events, allergic reactions, or skin irritations. The investigation revealed that the wrinkle score slightly decreased for the right and left side of the face following four weeks of serum application. However, this decrease was not significant (p>0.05) based on the Wilcoxon matched pairs tests for the wrinkle scores (right side p=0.060 and left side p=0.176) and Truskin Ages® results (right side p=0.096 and left side p=0.489).Comparing the data from the right side with that from the left side of the face revealed that neither demonstrated a significant reduction in wrinkle score (p=0.829) or Truskin Ages® results (p=0.804). Argireline was included in the serum applied to the right side of the face. However, no statistical significance was seen in the results on this side of the face indicating any possible effects.

Conclusion

Wrinkle scores and Truskin Ages® results were observed to decrease non-significantly following the application of a skin serum involving hyaluronic acid. The Visia® imaging method was used to analyze the data objectively. Differences between both sides of the face that were treated with and without Argireline were not statistically significant. Therefore, the effect of Argireline was not proven. While Argireline presented with low toxicity, its efficacy was found not to be significant. Therefore, it is not deemed to be an alternative treatment to botulinum toxin.

Polydioxanone Bioactive Sutures-Acetyl Hexapeptide-8 (Argireline): An Intelligent System for Controlled Release in Facial Harmonization

Introduction

We propose a new facial lifting protocol using polydioxanone (PDO) threads embedded in acetyl hexapeptide-8 (Argireline [Arg]). We assume that Arg reinforces the effects of PDO threads, as it is a mimetic of botulinum toxin. Because the PDO suture is hydrolyzable, this assumption is analyzed by instrumental analysis.

Objective

To demonstrate the capacity of the PDO suture as a system for the controlled release of acetyl hexapeptide-8 to apply in deep wrinkles of the upper third.

Materials and Methods

Three segments of 1-cm long 21G PDO threads immersed in 1 mL of Arg. PDO threads were observed under an optical, electron microscope at 24, 48, and 72 h later. They were also weighed before and after being soaked in Arg, and employing ultraviolet (UV)-visible spectroscopy, the release rate of Arg from the PDO suture was measured. Finally, was insert the thread PDO-Arg following a protocol designed especially for deep static wrinkles in the upper third.

Results

The electronic weighing revealed that the PDO thread enjoys capillarity by the peptide, doubling its weight every 24 h. UV spectra revealed that PDO thread is a well-controlled release system for Arg, allowing its sustained release for 1 h. Optical and electronic photomicrographs confirm the swelling of the PDO thread by absorbing Arg by its capillarity, but this hydrophilicity does not lead to its premature physical degradation.

Conclusions

The PDO thread system with Arg is an intelligent bioactive system useful in facial harmonization. It recommend conduct clinical trial to verify his superior lifting effect.

A nanohybrid synthesized by polymeric assembling Au(I)-peptide precursor for anti-wrinkle function

A major sign of aging is wrinkles (dynamic lines and static lines) on the surface of the skin. In spite of Botulinum toxin's favorable therapeutic effect today, there have been several reports of its toxicity and side effects. Therefore, the development of an effective and safe wrinkle-fighting compound is imperative. An antioxidant-wrinkle effect was demonstrated by the peptide that we developed and synthesized, termed Skin Peptide. Aiming at the intrinsic defects of the peptide such as hydrolysis and poor membrane penetration, we developed a general approach to transform the Skin Peptide targeting intracellular protein-protein interaction into a bioavailable peptide-gold spherical nano-hybrid, Skin Pcluster. As expected, the results revealed that Skin Pcluster reduced the content of acetylcholine released by neurons in vitro, and then inhibit neuromuscular signal transmission. Additionally, human experiments demonstrated a significant de-wrinkle effect. Moreover, Skin Pcluster is characterized by a reliable safety profile. Consequently, anti-wrinkle peptides and Skin Pcluster nanohybrids demonstrated innovative anti-wrinkle treatments and have significant potential applications.

Plasminogen-derived peptide promotes adipogenic differentiation of preadipocytes in vitro and in vivo

Soft tissue defects caused by adipose tissue loss can result in various conditions such as lipodystrophy in congenital diseases, trauma secondary to ageing, and mastectomy in breast cancer; fat grafting is commonly performed to restore these defects. Although various enrichment strategies have been studied, novel therapeutics that are cost-effective, safe, technologically easy to manufacture, and minimally invasive are required. In this study, we identified a novel peptide derived from plasminogen, named plasminogen-derived peptide-1 (PLP-1), which showed adipogenic differentiation potential and led to an increase in the expression levels of adiponectin, C1Q and collagen domain containing protein, fatty acid-binding protein 4, and CCAAT/enhancer-binding protein-alpha. In vivo experiments confirmed an increase in the rate of adipocyte differentiation and the expression levels of CD31 in the PLP-1-treated mice groups. These results suggested that PLP-1 plays an important role in promoting the differentiation of preadipocytes and may be useful for developing therapeutic approaches to treat adipose tissue defects.

A Practical Peptide Synthesis Workflow Using Amino-Li-Resin

Herein we report a practical approach for peptide synthesis using second-generation fibrous polyacrylamide resin (Li-resin, “Li” is coming from the name of its inventor, Yongfu Li). This resin with the corresponding handle was used for solid phase peptide synthesis (SPPS) using a fluorenylmethoxycarbonyl (Fmoc) approach. We reveal that the most appropriate mixing and filtration strategy when using amino-Li-resin in SPPS is via shaking and gravity filtration, instead of mechanical stirring and suction filtration used with other resins. The strategy was demonstrated with the SPPS of H-Tyr-Ile-Ile-Phe-Leu-NH₂, which contains the difficult sequence Ile-Ile. The peptide was obtained with excellent purity and yield. We are confident that this strategy will be rapidly implemented by other peptide laboratories.

Enhancement of Skin Delivery of Drugs Using Proposome Depends on Drug Lipophilicity

The study aims to investigate the propylene glycol-based liposomes named 'proposomes' in enhancing skin permeation of drugs with different physicochemical properties. Ibuprofen, tofacitinib citrate, rhodamine B, and lidocaine were loaded into proposomes. These drug formulations were analyzed for particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro skin permeation. The confocal laser scanning microscopy was performed on skin treated with calcein and rhodamine B laden proposomes. The transdermal delivery relative to physicochemical properties of drugs such as logP, melting point, molecular weight, solubility, etc., were analyzed. We tested the safety of the proposomes using reconstructed human skin tissue equivalents, which were fabricated in-house. We also used human cadaver skin samples as a control. The proposomes had an average diameter of 128 to 148 nm. The drug's entrapment efficiencies were in the range of 42.9-52.7%, translating into the significant enhancement of drug permeation through the skin. The enhancement ratio was 1.4 to 4.0, and linearly correlated to logP, molecular weight, and melting point. Confocal imaging also showed higher skin permeation of calcein and rhodamine B in proposome than in solution. The proposome was found safe for skin application. The enhancement of skin delivery of drugs through proposomes was dependent on the lipophilicity of the drug. The entrapment efficiency was positively correlated with logP of the drug, which led to high drug absorption.

Enhanced skin retention and permeation of a novel peptide via structural modification, chemical enhancement, and microneedles

Hyperpigmentation is a common skin condition with serious psychosocial consequences. Decapeptide-12, a novel peptide, has been found to be safer than hydroquinone in reducing melanin content, with efficacy up to more than 50% upon 16 weeks of twice-daily treatment. However, the peptide suffers from limited transcutaneous penetration due to its hydrophilicity and high molecular weight. Therefore, decapeptide-12 was modified by adding a palmitate chain in an attempt to overcome this limitation. Molecular docking results showed that the two peptides exhibited similar biological activity towards tyrosinase. We also tested the effect of chemical penetration enhancers and microneedles to deliver the two peptides into and through skin, using an in vitro human skin permeation method. It was shown that the palm-peptide achieved the best skin retention owing to the increased lipophilicity. In addition, skin permeation of the palm-peptides was enhanced by the chemical skin penetration enhancers, namely, oleic acid and menthol. Skin permeation of the native peptide was enhanced by the microneedle patch but not the chemical skin penetration enhancers. Cutaneous absorption of the palm-peptides was estimated to have achieved its therapeutic concentration within skin. The combinatory approach of using molecular modification, chemical penetration enhancement, and microneedle patch proves to be useful to enhanceskin permeation of the peptides.

DD04107-Derived neuronal exocytosis inhibitor peptides: Evidences for synaptotagmin-1 as a putative target

The analgesic peptide DD04107 (Pal-EEMQRR-NH₂) and its acetylated analogue inhibit α-calcitonin gene-related peptide (α-CGRP) exocytotic release from primary sensory neurons. Examining the crystal structure of the SNARE-Synaptotagmin-1(Syt1) complex, we hypothesized that these peptides could inhibit neuronal exocytosis by binding to Syt1, hampering at least partially its interaction with the SNARE complex. To address this hypothesis, we first interrogate the role of individual side-chains on the inhibition of α-CGRP release, finding that E1, M3, Q4 and R6 residues were crucial for activity. CD and NMR conformational analysis showed that linear peptides have tendency to adopt α-helical conformations, but the results with cyclic analogues indicated that this secondary structure is not needed for activity. Isothermal titration calorimetry (ITC) measurements demonstrate a direct interaction of some of these peptides with Syt1-C2B domain, but not with Syt7-C2B region, indicating selectivity. As expected for a compound able to inhibit α-CGRP release, cyclic peptide derivative Pal-E-cyclo[EMQK]R-NH₂ showed potent in vivo analgesic activity, in a model of inflammatory pain. Molecular dynamics simulations provided a model consistent with K_D values for the interaction of peptides with Syt1-C2B domain, and with their biological activity. Altogether, these results identify Syt1 as a potential new analgesic target.

Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals

This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used in skin regeneration, with moisturizing and anti-ageing effects. HA molecular weight influences its penetration into the skin and its biological activity. Considering that, nowadays, hyaluronic acid has a wide use and a multitude of applications (in ophthalmology, arthrology, pneumology, rhinology, aesthetic medicine, oncology, nutrition, and cosmetics), the present study describes the main aspects related to its use in cosmetology. The biological effect of HA on the skin level and its potential adverse effects are discussed. Some available cosmetic products containing HA have been identified from the brand portfolio of most known manufacturers and their composition was evaluated. Further, additional biological effects due to the other active ingredients (plant extracts, vitamins, amino acids, peptides, proteins, saccharides, probiotics, etc.) are presented, as well as a description of their possible toxic effects.

Neurocosmetics in Skincare—The Fascinating World of Skin–Brain Connection: A Review to Explore Ingredients, Commercial Products for Skin Aging, and Cosmetic Regulation

The “modern” cosmetology industry is focusing on research devoted to discovering novel neurocosmetic functional ingredients that could improve the interactions between the skin and the nervous system. Many cosmetic companies have started to formulate neurocosmetic products that exhibit their activity on the cutaneous nervous system by affecting the skin’s neuromediators through different mechanisms of action. This review aims to clarify the definition of neurocosmetics, and to describe the features of some functional ingredients and products available on the market, with a look at the regulatory aspect. The attention is devoted to neurocosmetic ingredients for combating skin stress, explaining the stress pathways, which are also correlated with skin aging. “Neuro-relaxing” anti-aging ingredients derived from plant extracts and neurocosmetic strategies to combat inflammatory responses related to skin stress are presented. Afterwards, the molecular basis of sensitive skin and the suitable neurocosmetic ingredients to improve this problem are discussed. With the aim of presenting the major application of Botox-like ingredients as the first neurocosmetics on the market, skin aging is also introduced, and its theory is presented. To confirm the efficacy of the cosmetic products on the market, the concept of cosmetic claims is discussed.

Does the use of Dermojet affect the concentration of platelet-rich plasma? An in vitro experimental investigation

Needle-free injection systems with high jet pressure have been used for seven decades for drug or vaccine administration via intradermal, subcutaneous, and intramuscular routes. These systems are used for the application of mesotherapy drugs in plastic surgery and dermatology. Platelet-rich plasma (PRP) tissue regeneration is applied intradermally by a needle for different indications, such as wound healing and scar revision. To prevent complaints such as pain, erythema, and ecchymosis by patients during this application, PRP was applied using Dermojet, a jet injector system with a spring-loaded system. In this study, after measuring the average platelet count in PRP preparations obtained from 18 volunteers, a 2.5 cc PRP shot into an empty tube was performed with Dermojet. The mean platelet count was measured in a homogenized tube. The same procedures were performed for platelet-poor plasma (PPP). The platelet loss rates for PRP and PPP were compared. In addition, the amount of PRP in each shot of the Dermojet was calculated. When PRP and PPP were applied using the Dermojet, platelet loss was 8.41% and 8.33%, respectively. The difference in the number of platelets formed in PRP and PPP when applied with Dermojet was not statistically significant. PRP application with needle-free injection systems, such as Dermojet, may be an alternative because of patient comfort and the negligible platelet loss compared with the PRP application with the standard needle injection.

Complications and Adverse Effects of Periocular Aesthetic Treatments

The popularity and variety of temporary and permanent periocular aesthetic treatments has increased over the past decade. Patients frequently present to eye clinics with ocular complications and side effects following these treatments, their severity ranging from ocular irritation from dry eyes to visual loss from vascular occlusion. A careful, thorough history is essential, as many patients may not associate aesthetic procedures with ocular complications, and some may be embarrassed to disclose this information. All ophthalmologists should understand the potential ocular sequelae of these treatments and be able to initiate treatment in sight-threatening cases. Wesummarises the current literature on ophthalmic complications of the most common periocular aesthetic treatments.

Protective and Anti-Aging Effects of 5 Cosmeceutical Peptide Mixtures on Hydrogen Peroxide-Induced Premature Senescence in Human Skin Fibroblasts

Skin aging usually leads to the excessive deterioration of the dermal extracellular matrix, loss of antimicrobial function, loss of skin barrier function, and a series of inflammatory processes. Bioactive peptides have been widely used in cosmetics due to their protective effects on skin and efficient absorption. Combination of different peptides may lead to synergistic or antagonistic effects, so different formulas need to be designed and tested properly. In this study, 5 functional cosmeceutical peptides were tested on their individual and mixed activities to detect a suitable anti-aging and protective formula from our experiments. After the individual activity test, the optimal concentration is 200 μg/mL of carnosine for the superoxide dismutase (SOD) activity, 200 μg/mL of GHK peptide for the hydroxyproline (HYP) content activity, 100 μg/mL of acetyl tetrapeptide-5 for the angiotensin-converting enzyme 1 activity, 400 μg/mL of hexapeptide-11 for the HYP content activity, and 400 μg/mL of acetyl hexapeptide-3 for the catecholamine content activity. According to the optimal concentration of these 5 cosmeceutical peptides, 6 formulations of peptide mixtures were designed and tested for their anti-aging activities and protective effects against hydrogen peroxide-induced premature senescence in human skin fibroblasts. One of the cosmeceutical peptide mixtures (carnosine + acetyl tetrapeptide-5 + hexapeptide-11 + acetyl hexapeptide-3) significantly reduced the intracellular malondialdehyde and hydroxyl free radical contents and increased the HYP and human elastin contents as well as the enzymatic activities of SOD and glutathione peroxidase. Our study suggests that this formula of cosmeceutical peptide mixtures could be a promising agent for use in anti-aging and protective cosmetics.

Multifunctional Tyrosinase Inhibitor Peptides with Copper Chelating, UV-Absorption and Antioxidant Activities: Kinetic and Docking Studies

Nature-derived tyrosinase inhibitors are of great industrial interest. Three monophenolase inhibitor peptides (MIPs) and three diphenolase inhibitor peptides (DIPs) from a previous study were investigated for their in vitro tyrosinase inhibitory effects, mode of inhibition, copper-chelating activity, sun protection factor (SPF) and antioxidant activities. DIP1 was found to be the most potent tyrosinase inhibitor (IC₅₀ = 3.04 ± 0.39 mM), which could be due to the binding interactions between its aromatic amino acid residues (Y2 and D7) with tyrosinase hotspots (H85, V248, H258, H263, F264, R268, V283 and E322) and its ability to chelate copper ion within the substrate-binding pocket. The conjugated planar rings of tyrosine and tryptophan may interact with histidine within the active site to provide stability upon enzyme-peptide binding. This postulation was later confirmed as the Lineweaver-Burk analysis had identified DIP1 as a competitive inhibitor and DIP1 also showed 36.27 ± 1.17% of copper chelating activity. In addition, DIP1 provided the highest SPF value (11.9 ± 0.04) as well as ferric reducing antioxidant power (FRAP) (5.09 ± 0.13 mM FeSO₄), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) (11.34 ± 0.90%) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (29.14 ± 1.36%) free radical scavenging activities compared to other peptides. These results demonstrated that DIP1 could be a multifunctional anti-tyrosinase agent with pharmaceutical and cosmeceutical applications.

Micro/nanodevices for assessment and treatment in stomatology and ophthalmology

Micro/nanodevices have been widely applied for the real-time monitoring of intracellular activities and the delivery of exogenous substances in the past few years. This review focuses on miniaturized micro/nanodevices for assessment and treatment in stomatology and ophthalmology. We first summarize the recent progress in this field by examining the available materials and fabrication techniques, device design principles, mechanisms, and biosafety aspects of micro/nanodevices. Following a discussion of biochemical sensing technology from the cellular level to the tissue level for disease assessment, we then summarize the use of microneedles and other micro/nanodevices in the treatment of oral and ocular diseases and conditions, including oral cancer, eye wrinkles, keratitis, and infections. Along with the identified key challenges, this review concludes with future directions as a small fraction of vast opportunities, calling for joint efforts between clinicians and engineers with diverse backgrounds to help facilitate the rapid development of this burgeoning field in stomatology and ophthalmology.

Geometrical optimisation of a personalised microneedle eye patch for transdermal delivery of anti-wrinkle small peptide

Acetyl-hexapeptide-3 (AHP-3) is a small peptide with good anti-wrinkle efficacy and safety profile. However, due to its hydrophilicity and high molecular weight, its skin permeation is generally poor. An innovative microneedle (MN) patch such as the curved, flexible or personalised MN patch is a viable avenue to deliver AHP-3. However, the well-researched geometrical relationship of MN on a flat MN patch cannot be assumed for these novel MN patches due to a complex mix of axial and shear forces. In this study, 3D printing was used for the fabrication of various MN patches with different MN geometries and curvatures. Both mechanical strength and skin penetration efficiency were used to determine the optimal MN geometry. The optimal MN geometry was then applied to the fabrication of a personalized MN patch (PMNP) for anti-wrinkle therapy, via 3D printing. In all, the general principles of MN geometrical effects on mechanical strength and skin penetration efficiency for a curved and a flat MN patch were similar. A MN height of 800 μm, tip diameter of 100 μm, interspacing of 800 μm and base diameter of 400 μm was observed to be the optimal MN geometry across all curvatures. In vitro skin permeation study demonstrated enhanced transdermal delivery of AHP-3 using the fabricated PMNP. Therefore, PMNP with optimized MN geometry can potentially be a novel approach to augment transdermal delivery of AHP-3 for effective wrinkle management.

The Effects of a Novel Series of KTTKS Analogues on Cytotoxicity and Proteolytic Activity

KTTKS is a matrikine that originates from the proteolytic hydrolysis of collagen. This peptide stimulates ECM production and types I and III collagen expression in vitro. A more stable form of KTTKS is pal-KTTKS, known as Matrixyl^® or palmitoyl pentapeptide-3. A series of novel pentapeptides, analogues of KTTKS with the general formula X-KTTKS-OH(NH₂), where X = acetyl, lipoyl, palmitoyl residues, was designed and synthesized. Their effect on amidolytic activity of urokinase, thrombin, trypsin, plasmin, t-PA, and kallikrein were tested. Cytotoxic tests on fibroblasts, as well as collagen and DNA biosynthesis tests for selected peptides, were also carried out. The test results showed that the most active plasmin inhibitors were palmitoyl peptides, whether in acid or amide form. No biological effects of lysine modification to arginine in the synthesized peptides were found. None of the synthesized peptides was not cytotoxic on fibroblasts, and three of them showed cell growth. These three compounds showed no concentration-activity relationship in the collagen and DNA biosynthesis assays.

Cell penetrating peptides: the potent multi-cargo intracellular carriers

Introduction: Cell penetrating peptides (CPPs) known as protein translocation domains (PTD), membrane translocating sequences (MTS), or Trojan peptides (TP) are able to cross biological membranes without clear toxicity using different mechanisms, and facilitate the intracellular delivery of a variety of bioactive cargos. CPPs could overcome some limitations of drug delivery and combat resistant strains against a broad range of diseases. Despite delivery of different therapeutic molecules by CPPs, they lack cell specificity and have a short duration of action. These limitations led to design of combined cargo delivery systems and subsequently improvement of their clinical applications. Areas covered: This review covers all our studies and other researchers in different aspects of CPPs such as classification, uptake mechanisms, and biomedical applications. Expert opinion: Due to low cytotoxicity of CPPs as compared to other carriers and final degradation to amino acids, they are suitable for preclinical and clinical studies. Generally, the efficiency of CPPs was suitable to penetrate the cell membrane and deliver different cargos to specific intracellular sites. However, no CPP-based therapeutic approach has approved by FDA, yet; because there are some disadvantages for CPPs including short half-life in blood, and nonspecific CPP-mediated delivery to normal tissue. Thus, some methods were used to develop the functions of CPPs in vitro and in vivo including the augmentation of cell specificity by activatable CPPs, specific transport into cell organelles by insertion of corresponding localization sequences, incorporation of CPPs into multifunctional dendrimeric or liposomal nanocarriers to improve selectivity and efficiency especially in tumor cells.

Anti-aging and Sunscreens: Paradigm Shift in Cosmetics

Skin, being one of the vital organs and a protective barrier needs to be pampered and taken care of from early childhood. It is the most visible and the widest exposed organ and by far reflects the general health condition and the aging process in humans. Both intrinsic and extrinsic factors contribute to this complex biological process of skin aging. In recent times, skin health and its beauty is perceived as an indicator of one’s health which has resulted in an increasing demand for anti-aging products. Exposure to UV radiation is considered to be one of the factors responsible for aging termed as photoaging. In this review, we have discussed the various factors which may accelerate the process of skin aging. Various approaches and strategies to delay the process of skin aging have been emphasized upon. The patents filed in the area of anti-aging and sunscreen products have also been reviewed to gain an insight into the new formulations which have been developed as an anti-aging product. There has been a tremendous rise in the cosmetic and cosmeceuticals market with products having a dual activity of anti-aging and sun protection. Research is constantly on the rise to ensure the safety of these products. Alternatives to the current topical application of sunscreen are being considered to overcome the drawback of reapplication of the sunscreen often which can be a boon to the cosmeceutical market.

Botulinum toxin (Botox) A for reducing the appearance of facial wrinkles: a literature review of clinical use and pharmacological aspect

Background: Botulinum toxin (Botox) consists of 7 types of neurotoxins; however, only toxins A and B are used clinically. Botox A is used for several disorders in the field of medicine, particularly in dermatology, for cosmetic purposes. It is produced by the bacterium Clostridium botulinum and can be used as a treatment to reduce the appearance of wrinkles in the upper areas of the face, elevate the eyebrows and treat problems such as hyperhidrosis, lichen simplex, pompholyx (dyshidrotic eczema) and acne vulgaris.

Objectives: This article provides a literature review regarding the general issue of Botox as a treatment for reducing facial wrinkle.

Discussion: Botox works by blocking the release of acetylcholine, resulting in paralysis of the local muscles, which usually occurs 24 hrs to two weeks following Botox injection. This effect will last three to six months. The optimal dose of cosmetic Botox in dermatology is 20 units. Botox is relatively safe and does not result in any adverse side effects. However, in certain circumstances, the effect of Botox will gradually resolve, resulting in reduced muscle paralysis over time.

Conclusion: Botox is good and safe medicine to reduce the appearance of facial wrinkles.

Improvements in chemical carriers of proteins and peptides

The successful intracellular delivery of biologically active proteins and peptides plays an important role for therapeutic applications. Indeed, protein/peptide delivery could overcome some problems of gene therapy, for example, controlling the expression levels and the integration of transgene into the host cell genome. Thus, protein/peptide drug delivery showed a promising and safe approach for treatment of cancer and infectious diseases. Due to the unique physical and chemical properties of proteins, their production (e.g., isolation, purification & formulation) and delivery represented significant challenges in pharmaceutical studies. Modification in the structural moieties of these protein/peptide drugs could improve their solubility, stability, crystallinity, lipophilicity, enzymatic susceptibility and targetability, and subsequently, therapies and cures against various diseases. Using the structural modification of protein/peptide, their delivery provided overall higher success rates including high specificity, high activity, bioreactivity and safety. Recently, biotechnological and pharmaceutical companies have tried to find novel techniques for the modifications and improve delivery systems/carriers. However, each carrier has its own benefits and drawbacks, and an appropriate carrier is often established by the physicochemical properties of protein or peptide, the ideal route of injection, and clinical characteristics of therapy. In this review, an attempt was made to give an overview on the chemical carriers for proteins and peptides as well as the recent advances in this field.