Nano-hydrogel embedded with quercetin and oleic acid as a new formulation in the treatment of diabetic foot ulcer: A pilot study

Hydrogel dressings for diabetic foot ulcer: A systematic review and meta-analysis

AIM

To investigate the differences in utility between conventional dressings and hydrogel dressings for the treatment of diabetic foot ulcer (DFU).

METHODS

The PubMed, Embase, Cochrane Library, CNKI, VIP and Wanfang databases were systematically searched up to 21 January 2023. Fixed/random-effect models were used to calculate the odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) for the effect size analysis, with heterogeneity determined by I2 statistics. Subgroup analyses of different classes of hydrogel were also conducted.

RESULTS

A total of 15 randomized controlled trials with 872 patients were eligible for the present analysis. Compared with conventional dressings, hydrogel dressings significantly improved the healing rate (OR 4.09, 95% CI 2.83 to 5.91), shortened the healing time (MD -11.38, 95% CI -13.11 to -9.66), enhanced granulation formation (MD -3.60, 95% CI -4.21 to -3.00) and epithelial formation (MD -2.82, 95% CI -3.19 to -2.46), and reduced the incidence of bacterial infection (OR 0.10, 95% CI 0.05 to 0.18).

CONCLUSION

The meta-analysis showed that hydrogel dressings are more effective in treating DFU compared with conventional dressings.

Harnessing the Power of Polyphenols: A New Frontier in Disease Prevention and Therapy

There are a wide variety of phytochemicals collectively known as polyphenols. Their structural diversity results in a broad range of characteristics and biological effects. Polyphenols can be found in a variety of foods and drinks, including fruits, cereals, tea, and coffee. Studies both in vitro and in vivo, as well as clinical trials, have shown that they possess potent antioxidant activities, numerous therapeutic effects, and health advantages. Dietary polyphenols have demonstrated the potential to prevent many health problems, including obesity, atherosclerosis, high blood sugar, diabetes, hypertension, cancer, and neurological diseases. In this paper, the protective effects of polyphenols and the mechanisms behind them are investigated in detail, citing the most recent available literature. This review aims to provide a comprehensive overview of the current knowledge on the role of polyphenols in preventing and managing chronic diseases. The cited publications are derived from in vitro, in vivo, and human-based studies and clinical trials. A more complete understanding of these naturally occurring metabolites will pave the way for the development of novel polyphenol-rich diet and drug development programs. This, in turn, provides further evidence of their health benefits.

Network pharmacology-based strategy combined with molecular docking to explore the potential mechanism of agarwood against recurrent aphthous stomatitis

To explore the antiinflammatory mechanism of agarwood on recurrent aphthous stomatitis (RAS). RAS is the most common mucosal disease in the oral cavity. The clinical application of traditional Chinese medicine found that agarwood has significant curative effect on peptic ulcer, but the effect and mechanism of agarwood on RAS remain unclear. This study is intended to predict the potential antiinflammatory mechanisms by which agarwood acts on RAS through network pharmacology and molecular docking. TCMSP database was used to screen the active components of agarwood. RAS targets were screened in Genecards, DisGeNET, and OMIM database. Venny, an online tool, screens for interacting genes between the two. Cytoscape software was used to construct the gene regulation map of active compounds target of agarwood. String Database building protein-protein interaction network. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathways were enriched in DAVID database. The key active ingredients and core targets were further verified by molecular docking. There were 9 effective compounds and 186 target genes in agarwood; RAS has 793 target genes. There were 41 interacting genes between agarwood and RAS. Interleukin 6, tumor necrosis factor, interleukin 1 beta, and cellular component motif ligand 2 may be key targets. Gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses predicted multiple pathways associated with RAS. Molecular docking results showed that the active compounds of agarwood combined well and stably with the target. The Chinese herbal medicine agarwood can relieve the inflammation of RAS through multiple targets and various ways. Its active compounds may be nominated as candidates for antiinflammatory drugs of RAS.

Successful topical treatment of human biofilms using multiple antibiotic elution from a collagen-rich hydrogel

Chronic non-healing wounds significantly strain modern healthcare systems, affecting 1-2% of the population in developed countries with costs ranging between $28.1 and $96.8 billion annually. Additionally, it has been established that chronic wounds resulting from comorbidities, such as peripheral vascular disease and diabetes mellitus, tend to be polymicrobial in nature. Treatment of polymicrobial chronic wounds with oral and IV antibiotics can result in antimicrobial resistance, leading to more difficult-to-treat wounds. Ideally, chronic ulcers would be topically treated with antibiotic combinations tailored to the microbiome of a patient's wound. We have previously shown that a topical collagen-rich hydrogel (cHG) can elute single antibiotics to inhibit bacterial growth in a manner that is nontoxic to mammalian cells. Here, we analyzed the microbiology of cultures taken from human patients diagnosed with diabetes mellitus suffering from chronic wounds present for more than 6 weeks. Additionally, we examined the safety of the elution of multiple antibiotics from collagen-rich hydrogel in mammalian cells in vivo. Finally, we aimed to create tailored combinations of antibiotics impregnated into cHG to successfully target and treat infections and eradicate biofilms cultured from human chronic diabetic wound tissue. We found that the majority of human chronic wounds in our study were polymicrobial in nature. The elution of multiple antibiotics from cHG was well-tolerated in mammalian cells, making it a potential topical treatment of the polymicrobial chronic wound. Finally, combinations of antibiotics tailored to each patient's microbiome eluted from a collagen-rich hydrogel successfully treated bacterial cultures isolated from patient samples via an in vitro assay.

The Influence of Honey and Hydrogel Products Therapy on Healing Time in Diabetic Foot

BACKGROUND

Diabetic foot ulcer is a serious and common complication of diabetes that often leads to significant morbidity and even amputation if not properly treated. Current treatment options, such as wound dressing, have limitations in promoting efficient healing. There is a need for effective interventions that can expedite the healing process and enhance the time required for complete healing.

METHODOLOGY

This prospective single-blinded randomized control trial studied diabetic mellitus type 2 patients with ulcer in their second-degree feet from February 2019 to February 2023 in the Diabetic Foot Center, King Fahad Specialist Hospital Al Qassim-KSA.

RESULTS

This study involved 120 patients with a mean age of 59.64 ± 10.21. And 63% to 52.5% of them were males and 57% to 47.5% were females. The mean healing time was about 12.76 ± 4.08 days. Cases were divided into 4 equal groups with altered treatment procedures: honey alone, hydrogel alone, honey, and hydrogel combination alternately (3 intervention groups), and fucidin ointment or cream alone (1 control group), with 30 participants in each group. We revealed that the mean healing times for honey alone, hydrogel alone, and honey and hydrogel alternately were 12.20, 13.97, and 10.83 days, respectively. While it was 14.03 days in the control Fucidin ointment or cream [significantly P < .05 (P = .004)].

CONCLUSION

From the findings of the present study, we noticed that faster healing time among diabetic foot cases could be accomplished by treatment with a combination of honey and hydrogel alternately. Therefore, this therapy is effective in reducing the risk of diabetic foot ulcers.

Quercetin as a Therapeutic Product: Evaluation of Its Pharmacological Action and Clinical Applications-A Review

Quercetin is the major polyphenolic flavonoid that belongs to the class called flavanols. It is found in many foods, such as green tea, cranberry, apple, onions, asparagus, radish leaves, buckwheat, blueberry, broccoli, and coriander. It occurs in many different forms, but the most abundant quercetin derivatives are glycosides and ethers, namely, Quercetin 3-O-glycoside, Quercetin 3-sulfate, Quercetin 3-glucuronide, and Quercetin 3'-metylether. Quercetin has antioxidant, anti-inflammatory, cardioprotective, antiviral, and antibacterial effects. It is found to be beneficial against cardiovascular diseases, cancer, diabetes, neuro-degenerative diseases, allergy asthma, peptic ulcers, osteoporosis, arthritis, and eye disorders. In pre-clinical and clinical investigations, its impacts on various signaling pathways and molecular targets have demonstrated favorable benefits for the activities mentioned above, and some global clinical trials have been conducted to validate its therapeutic profile. It is also utilized as a nutraceutical due to its pharmacological properties. Although quercetin has several pharmacological benefits, its clinical use is restricted due to its poor water solubility, substantial first-pass metabolism, and consequent low bioavailability. To circumvent this limited bioavailability, a quercetin-based nanoformulation has been considered in recent times as it manifests increased quercetin uptake by the epithelial system and enhances the delivery of quercetin to the target site. This review mainly focuses on pharmacological action, clinical trials, patents, marketed products, and approaches to improving the bioavailability of quercetin with the use of a nanoformulation.

Carboxymethyl Chitosan Hydrogels for Effective Wound Healing-An Animal Study

Hydrogels have various applications in medicine, for example, in systems for controlled drug release or as wound dressings, where they provide an appropriate environment for healing and constitute a barrier to microorganisms. The aim of this study was to evaluate the action of carboxymethyl chitosan (CMCS) hydrogels in wound healing therapy in vivo using a laboratory rat model. The hydrogels were formed from aqueous solutions of a CMCS biopolymer via electron beam irradiation, with the presence of a crosslinking agent of poly(ethylene glycol) diacrylate. A histopathological examination of injured tissue, using a model of a hard-to-heal wound, indicated that the CMCS hydrogel supported healing. The new gel dressing, being noncytotoxic, presents great potential in wound treatment, with positive effects on the amount of inflammatory infiltration, young collagen formation, and the degree of epidermalization. A key advantage of the current approach (i.e., using competitive radiation technology for synthesis) is that it includes only one step, with the product being sterilized as it is synthesized. The hydrogel effectively supports wound healing and can serve as a bio-based and biodegradable platform for other medical applications.

Pharmacological Activity of Flavonoid Quercetin and Its Therapeutic Potential in Testicular Injury

Quercetin is a natural flavonoid widely found in natural fruits and vegetables. Recent studies have shown that quercetin mediates multiple beneficial effects in a variety of organ damage and diseases, and is considered a healthcare supplement with health-promoting potential. Male infertility is a major health concern, and testicular damage from multiple causes is an important etiology. Previous studies have shown that quercetin has a protective effect on reproductive function. This may be related to the antioxidant, anti-inflammatory, and anti-apoptotic biological activities of quercetin. Therefore, this paper reviews the mechanisms by which quercetin exerts its pharmacological activity and its role in testicular damage induced by various etiologies. In addition, this paper compiles the application of quercetin in clinical trials, demonstrating its practical effects in regulating blood pressure and inhibiting cellular senescence in human patients. However, more in-depth experimental studies and clinical trials are needed to confirm the true value of quercetin for the prevention and protection against testicular injury.

Scoping Review of Hydrogel Therapies in the Treatment of Diabetic Chronic Wounds

Chronic diabetic wounds are a significant issue that can be treated with topical hydrogel therapies. The aim of this study was to review the different compositions of hydrogel that have been developed and analyze their clinical relevance in the treatment of chronic diabetic wounds.

Methods

We conducted a scoping review in which twelve articles were selected for review after applying relevant inclusion and exclusion criteria using a two-reviewer strategy. Data extracted from these studies was used to answer the following research question: What is the composition of hydrogels used to treat chronic diabetic wounds and how effective are they?

Results

We analyzed five randomized controlled trials, two retrospective studies, three reviews, and two case reports. Hydrogel compositions discussed included mesenchymal stem cell sheets, carbomer, collagen, and alginate hydrogels, as well as hydrogels embedded with platelet-derived growth factor. Synthetic hydrogels, largely composed of carbomers, were found to have high levels of evidence supporting their wound healing properties, though few articles described their routine use in a clinical setting. Collagen hydrogels dominate the present-day hydrogel market in the clinical treatment of chronic diabetic wounds. The augmentation of hydrogels with therapeutic biomaterials is a new field of hydrogel research, with studies demonstrating promising early in vitro and in vivo animal studies demonstrating promising early results for in vitro and in vivo animal investigations.

Conclusions

Current research supports hydrogels as a promising topical therapy in the treatment of chronic diabetic wounds. Augmenting Food & Drug Administration-approved hydrogels with therapeutic substances remains an interesting early area of investigation.

Antioxidant Biomaterials in Cutaneous Wound Healing and Tissue Regeneration: A Critical Review

Natural-based biomaterials play an important role in developing new products for medical applications, primarily in cutaneous injuries. A large panel of biomaterials with antioxidant properties has revealed an advancement in supporting and expediting tissue regeneration. However, their low bioavailability in preventing cellular oxidative stress through the delivery system limits their therapeutic activity at the injury site. The integration of antioxidant compounds in the implanted biomaterial should be able to maintain their antioxidant activity while facilitating skin tissue recovery. This review summarises the recent literature that reported the role of natural antioxidant-incorporated biomaterials in promoting skin wound healing and tissue regeneration, which is supported by evidence from in vitro, in vivo, and clinical studies. Antioxidant-based therapies for wound healing have shown promising evidence in numerous animal studies, even though clinical studies remain very limited. We also described the underlying mechanism of reactive oxygen species (ROS) generation and provided a comprehensive review of ROS-scavenging biomaterials found in the literature in the last six years.

Phytotherapy in Diabetic Foot Ulcers: A Promising Strategy for Effective Wound Healing

Despite the advancement in wound care, the effective therapy of chronic diabetic ulcers continues to be a challenge. Wound healing is a highly controlled process, which involves a sequence of complex overlapping steps. This healing pathway comprises of hemostasis, inflammation, proliferative, and remodeling phases. Recent evidence suggests that phytomedicines can prevent or repair different kinds of destructive cellular damage, including chronic wounds. Several phytochemicals such as polyphenols, alkaloids, flavonoids, terpenoids, and glycosides have pleiotropic effects, including stimulation of fibroblast proliferation, the main step in wound healing. Besides, the mechanism involves induction of collagen synthesis, migration, and reepithelization and their antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory actions. Similarly, the use of phytochemicals alone or as an adjuvant with standard therapy has demonstrated promising results in managing complications in the diabetic foot. For instance, the extract of Carica papaya has been shown antioxidant, antimicrobial, and anti-inflammatory, and immunomodulatory effects, which, together with proteolytic enzymatic activity, contributes to its wound healing property. It is generally believed that phytotherapy has no or minimal toxicity than synthetic therapeutic agents, favoring its use in diabetic foot ulcer management. The current review highlights the selected phytochemicals and their sources; and potential application in diabetic foot ulcer management.Key teaching points and nutritional relevanceCurrently, phytochemicals have been shown wide potential in disease. management including alleviating clinical manifestations, preventing degenerative disease, and curing illness.Increased evidence of phytochemical as anti-infective and anti-inflammatory suggests its role in the management of diabetic foot ulcer(DFU).Potential benefit along with minimal adverse effect favors its application as adjuvant therapy.Further research is needed to standardize its dose and formulation to enhance its clinical application in DFU management.

Polylactic Acid/Poly(vinylpyrrolidone) Co-Electrospun Fibrous Membrane as a Tunable Quercetin Delivery Platform for Diabetic Wounds

Diabetic wound infections (DWI) represent one of the most costly and disruptive complications in diabetic mellitus. The hyperglycemic state induces a persistent inflammation with immunological and biochemical impairments that promotes delayed wound healing processes and wound infection that often results in extended hospitalization and limb amputations. Currently, the available therapeutic options for the management of DWI are excruciating and expensive. Hence, it is essential to develop and improve DWI-specific therapies able to intervene on multiple fronts. Quercetin (QUE) exhibits excellent anti-inflammatory, antioxidant, antimicrobial and wound healing properties, which makes it a promising molecule for the management of diabetic wounds. In the present study, Poly-lactic acid/poly(vinylpyrrolidone) (PP) co-electrospun fibers loaded with QUE were developed. The results demonstrated a bimodal diameter distribution with contact angle starting from 120°/127° and go to 0° in less than 5 s indicating the hydrophilic nature of fabricated samples. The release QUE kinetics, analyzed in simulated wound fluid (SWF), revealed a strong initial burst release, followed by a constant and continuous QUE release. Moreover, QUE-loaded membranes present excellent antibiofilm and anti-inflammatory capacity and significantly reduce the gene expression of M1 markers tumor necrosis factor (TNF)-α, and IL-1β in differentiated macrophages. In conclusion, the results suggested that the prepared mats loaded with QUE could be a hopeful drug-delivery system for the effective treatment of diabetic wound infections.

Flavonoids as Potential Wound-Healing Molecules: Emphasis on Pathways Perspective

Wounds are considered to be a serious problem that affects the healthcare sector in many countries, primarily due to diabetes and obesity. Wounds become worse because of unhealthy lifestyles and habits. Wound healing is a complicated physiological process that is essential for restoring the epithelial barrier after an injury. Numerous studies have reported that flavonoids possess wound-healing properties due to their well-acclaimed anti-inflammatory, angiogenesis, re-epithelialization, and antioxidant effects. They have been shown to be able to act on the wound-healing process via expression of biomarkers respective to the pathways that mainly include Wnt/β-catenin, Hippo, Transforming Growth Factor-beta (TGF-β), Hedgehog, c-Jun N-Terminal Kinase (JNK), NF-E2-related factor 2/antioxidant responsive element (Nrf2/ARE), Nuclear Factor Kappa B (NF-κB), MAPK/ERK, Ras/Raf/MEK/ERK, phosphatidylinositol 3-kinase (PI3K)/Akt, Nitric oxide (NO) pathways, etc. Hence, we have compiled existing evidence on the manipulation of flavonoids towards achieving skin wound healing, together with current limitations and future perspectives in support of these polyphenolic compounds as safe wound-healing agents, in this review.

Advances in Quercetin for Drug-Resistant Cancer Therapy: Mechanisms, Applications, and Delivery Systems

Quercetin (QUE), a natural flavone abundantly discovered in fruits, has gained attention for its potential health benefits due to its unique structure. In addition, epidemiological and clinical studies have shown promising antioxidant activity of QUE aiming to treat various diseases, including cancer. This article's purpose is to provide an overview of recent advances in the use of QUE for drug-resistant cancer therapies, focusing on its mechanisms, applications, and delivery systems. The review discusses the structure-function relationship of QUE and its role in mitigating various disorders. Furthermore, it highlights the impact of QUE on cancer and cancer stem cells, elucidating the signaling pathways at the cellular and molecular levels involved. Additionally, the review explores the mechanistic role of QUE in reversing drug resistance in different types of drug-resistant cancers. Moreover, it presents a comprehensive analysis of drug diverse delivery strategies employed for effective cancer treatment using QUE. Clinical studies investigating the safety and bioavailability of QUE are also discussed. Finally, the review concludes with future directions, emphasizing the use of cost-effective and efficient protein and peptide-based self-assembling hydrogels for targeted delivery of QUE.

The Promising Hydrogel Candidates for Preclinically Treating Diabetic Foot Ulcer: A Systematic Review and Meta-Analysis

Significance: Diabetic foot ulcer (DFU) causes high amputation rates owing to its aberrant wound healing. Traditional dressings cannot effectively contribute to DFU healing. Functional hydrogels have been proposed as a promising novel dressing to treat DFU in future, but the evidence for various hydrogels to heal DFU is still ambiguous. Recent Advances: In accordance with PRISMA and CONSORT guidelines, a meta-analysis was performed to evaluate the efficacy of functional hydrogels. Four electronic databases and one website were used for data searching. Twenty-four animal studies and six clinical trials met the inclusion criteria with a total of 399 diabetic murine models and 278 patients with DFU. Critical Issues: Functional hydrogels accelerated the healing progress for DFU and relieved symptoms in patients. According to their characteristics, the functional hydrogels were divided into antioxidant hydrogel (AOH), antibacterial hydrogel (ABH), multifunctional hydrogel (MFH), proangiogenic hydrogel, and hydrogel promoting proliferation (PPH). By network meta-analysis, AOH and MFH were considered the premium options for treating wounds of diabetic patients at whole stage. Future Direction: Functional hydrogels effectively accelerate healing rates in wounds of diabetic animals. Hydrogels of AOH and MFH might become the ideal candidates for clinical trials on DFU treatment, based on the meta-analyses from the reported work. Early treatment with AOH followed a week later with ABH, which might become an advanced strategy for DFU in future. This information is very important for researchers or/and physicians in taking consideration for alternate application of hydrogel dressings. Scope and Significance: The treatment of DFU imposes a huge burden on medical workers. If DFU is not treated properly, patients will have to suffer from amputation and from spiritual agony. Although various topical dressings have been designated for DFU, the healing ability of those dressings is still unknown well. In this review and meta-analysis, we quantitatively evaluated the reported outcomes of functional hydrogels, pure scaffolds, and controls in 2-week interval. Healing ability of various kinds of functional hydrogels was also assessed in different stages of wound, aiming to screen promising candidates for DFU treatment. This information is valuable in designing smart dressings for researchers or/and physicians in future. Translational Relevance: Considering many external factors like formation of bacterial film and internal factors like hyperglycemia, the progress during DFU healing could involve many biochemical aspects. Persistent inflammation, oxidation stress, and impaired angiogenesis lead to prolonged wound healing and even lethal outcomes. Thus, improvement of topical conditions and inhibition of adverse factors will lead to the alleviated morbidity and even mortality. Clinical Relevance: DFU brings about great burden on patients and medical staffs because of high morbidity and poor prognosis. Improper and powerless treatment might induce high rates of amputation and mortality. Functional hydrogels, mimicking extracellular matrices, would provide the tissue with suitable media and functions to promote DFU healing. The application of various types of hydrogels could be a promising solution to heal DFU and reduce adverse events and costs.

Nutraceuticals: A Promising Approach Towards Diabetic Neuropathy

BACKGROUND

Various nutraceuticals from different sources have various beneficial actions and have been reported for many years. The important findings from the research conducted using various nutraceuticals exhibiting significant physiological and pharmacological activities have been summarized.

METHODS

An extensive investigation of literature was done using several worldwide electronic scientific databases like PUBMED, SCOPUS, Science Direct, Google Scholar, etc. The entire manuscript is available in the English language that is used for our various compounds of interest. These databases were thoroughly reviewed and summarized.

RESULTS

Nutraceuticals obtained from various sources play a vital role in the management of peripheral neuropathy associated with diabetes. Treatment with nutraceuticals has been beneficial as an alternative in preventing the progression. In particular, in vitro and in vivo studies have revealed that a variety of nutraceuticals have significant antioxidant and anti-inflammatory properties that may inhibit the early diabetes-driven molecular mechanisms that induce DPN.

CONCLUSION

Nutraceuticals obtained from different sources like a plant, an animal, and marine have been properly utilized for the safety of health. In our opinion, this review could be of great interest to clinicians, as it offers a complementary perspective on the management of DPN. Trials with a well-defined patient and symptom selection have shown robust pharmacological design as pivotal points to let these promising compounds become better accepted by the medical community.

Flavonoids and saponins: What have we got or missed?

BACKGROUND

Flavonoids and saponins are important bioactive compounds that have attracted wide research interests. This review aims to summarise the state of the art of the pharmacology, toxicology and clinical efficacy of these compounds.

METHODS

Data were retrieved from PubMed, Cochrane Library, Web of Science, Proquest, CNKI, Chongqing VIP, Wanfang, NPASS and HIT 2.0 databases. Meta-analysis and systematic reviews were evaluated following the PRISMA guideline. Statistical analyses were conducted using SPSS23.0.

RESULTS

Rising research trends on flavonoids and saponins were observed since the 1990s and the 2000s, respectively. Studies on pharmacological targets and activities of flavonoids and saponins represent an important area of research advances over the past decade, and these important resources have been documented in open-access specialised databases and can be retrieved with ease. The rising research on flavonoids and saponins can be attributed, at least in part, to their links with some highly investigated fields of research, e.g., oxidative stress, inflammation and cancer; i.e., 6.88% and 3.03% of publications on oxidative stress cited by PubMed in 1990 - 2021 involved flavonoids and saponins, respectively, significantly higher than the percentage involving alkaloids (1.88%). The effects of flavonoids concern chronic venous insufficiency, cervical lesions, diabetes, rhinitis, dermatopathy, prostatitis, menopausal symptoms, angina pectoris, male pattern hair loss, lymphocytic leukaemia, gastrointestinal diseases and traumatic cerebral infarction, etc, while those of saponins may have impact on venous oedema in chronic deep vein incompetence, erectile dysfunction, acute impact injuries and systemic lupus erythematosus, etc. The volume of in vitro research appears way higher than in vivo and clinical studies, with only 10 meta-analyses and systematic reviews (involving 290 interventional and observational studies), and 36 clinical studies on flavonoids and saponins. Data are sorely needed on pharmacokinetics, in vitro pan-assay interferences, purity of tested compounds, interactions in complex herbal extracts, real impact of anti-oxidative strategies, and mid- and long-term toxicities. To fill these important gaps, further investigations are warranted. On the other hand, drug interactions may cause adverse effects but might also be useful for synergism, with the goals of enhancing effects or of detoxifying. Furthermore, the interactions between phytochemicals and the intestinal microbiota are worth investigating as the field may present a promising potential for novel drug development.

Nanodelivery of Dietary Polyphenols for Therapeutic Applications

Advancement in nanotechnology has unleashed the therapeutic potentials of dietary polyphenols by enhancing bioavailability, improving biological half-life, and allowing site-specific drug delivery. In this review, through citation of relevant literature reports, we discuss the application of nano-pharmaceutical formulations, such as solid lipid nanoparticles, nano-emulsions, nano-crystals, nano-polymersomes, liposomes, ethosomes, phytosomes, and invasomes for dietary polyphenols. Following this, we highlight important studies concerning different combinations of nano formulations with dietary polyphenols (also known as nanophytopolyphenols). We also provide nano-formulation paradigms for enhancing the physicochemical properties of dietary polyphenols. Finally, we highlight the latest patents that were granted on nano-formulations of dietary polyphenols. Based on our review, we observe that nanosized delivery of herbal constituents, spices, and dietary supplements have the ability to improve biological processes and address issues connected with herbal treatments.

Recent advances of the nanocomposite hydrogel as a local drug delivery for diabetic ulcers

Diabetic ulcer is a serious complication of diabetes. Compared with that of healthy people, the skin of patients with a diabetic ulcer is more easily damaged and difficult to heal. Without early intervention, the disease will become increasingly serious, often leading to amputation or even death. Most current treatment methods cannot achieve a good wound healing effect. Numerous studies have shown that a nanocomposite hydrogel serves as an ideal drug delivery method to promote the healing of a diabetic ulcer because of its better drug loading capacity and stability. Nanocomposite hydrogels can be loaded with one or more drugs for application to chronic ulcer wounds to promote rapid wound healing. Therefore, this paper reviews the latest progress of delivery systems based on nanocomposite hydrogels in promoting diabetic ulcer healing. Through a review of the recent literature, we put forward the shortcomings and improvement strategies of nanocomposite hydrogels in the treatment of diabetic ulcers.

Cellular Senescence in Aging, Tissue Repair, and Regeneration

SUMMARY

Society and our healthcare system are facing unprecedented challenges due to the expansion of the older population. As plastic surgeons, we can improve care of our older patients through understanding the mechanisms of aging that inevitably impact their outcomes and well-being. One of the major hallmarks of aging, cellular senescence, has recently become the focus of vigorous research in academia and industry. Senescent cells, which are metabolically active but in a state of stable cell cycle arrest, are implicated in causing aging and numerous age-related diseases. Further characterization of the biology of senescence revealed that it can be both detrimental and beneficial to organisms depending on tissue context and senescence chronicity. Here, we review the role of cellular senescence in aging, wound healing, tissue regeneration, and other domains relevant to plastic surgery. We also review the current state of research on therapeutics that modulate senescence to improve conditions of aging.

Evolving spectrum of diabetic wound: Mechanistic insights and therapeutic targets

Diabetes mellitus is a chronic metabolic disorder resulting in an increased blood glucose level and prolonged hyperglycemia, causes long term health conse-quences. Chronic wound is frequently occurring in diabetes patients due to compromised wound healing capability. Management of wounds in diabetic patients remains a clinical challenge despite many advancements in the field of science and technology. Increasing evidence indicates that alteration of the biochemical milieu resulting from alteration in inflammatory cytokines and matrix metalloproteinase, decrease in fibroblast and keratinocyte functioning, neuropathy, altered leukocyte functioning, infection, etc., plays a significant role in impaired wound healing in diabetic people. Apart from the current pharmacotherapy, different other approaches like the use of conventional drugs, antidiabetic medication, antibiotics, debridement, offloading, platelet-rich plasma, growth factor, oxygen therapy, negative pressure wound therapy, low-level laser, extracorporeal shock wave bioengineered substitute can be considered in the management of diabetic wounds. Drugs/therapeutic strategy that induce angiogenesis and collagen synthesis, inhibition of MMPs, reduction of oxidative stress, controlling hyperglycemia, increase growth factors, regulate inflammatory cytokines, cause NO induction, induce fibroblast and keratinocyte proliferation, control microbial infections are considered important in controlling diabetic wound. Further, medicinal plants and/or phytoconstituents also offer a viable alternative in the treatment of diabetic wound. The focus of the present review is to highlight the molecular and cellular mechanisms, and discuss the drug targets and treatment strategies involved in the diabetic wound.

Current Advances in the Development of Hydrogel-Based Wound Dressings for Diabetic Foot Ulcer Treatment

Diabetic foot ulcers (DFUs) are one of the most prevalent complications associated with diabetes mellitus. DFUs are chronic injuries that often lead to non-traumatic lower extremity amputations, due to persistent infection and other ulcer-related side effects. Moreover, these complications represent a significant economic burden for the healthcare system, as expensive medical interventions are required. In addition to this, the clinical treatments that are currently available have only proven moderately effective, evidencing a great need to develop novel strategies for the improved treatment of DFUs. Hydrogels are three-dimensional systems that can be fabricated from natural and/or synthetic polymers. Due to their unique versatility, tunability, and hydrophilic properties, these materials have been extensively studied for different types of biomedical applications, including drug delivery and tissue engineering applications. Therefore, this review paper addresses the most recent advances in hydrogel wound dressings for effective DFU treatment, providing an overview of current perspectives and challenges in this research field.

Quercetin: A Molecule of Great Biochemical and Clinical Value and Its Beneficial Effect on Diabetes and Cancer

Quercetin belongs to the broader category of polyphenols. It is found, in particular, among the flavonols, and along with kaempferol, myricetin and isorhamnetin, it is recognized as a foreign substance after ingestion in contrast to vitamins. Quercetin occurs mainly linked to sugars with the most common compounds being quercetin-3-O-glucoside or as an aglycone, especially in the plant population. The aim of this review is to present a recent bibliography on the mechanisms of quercetin absorption and metabolism, bioavailability, and antioxidant and the clinical effects in diabetes and cancer. The literature reports a positive effect of quercetin on oxidative stress, cancer, and the regulation of blood sugar levels. Moreover, research-administered drug dosages of up to 2000 mg per day showed mild to no symptoms of overdose. It should be noted that quercetin is no longer considered a carcinogenic substance. The daily intake of quercetin in the diet ranges 10 mg-500 mg, depending on the type of products consumed. This review highlights that quercetin is a valuable dietary antioxidant, although a specific daily recommended intake for this substance has not yet been determined and further studies are required to decide a beneficial concentration threshold.

Quercetin: an effective polyphenol in alleviating diabetes and diabetic complications

Various studies, especially in recent years, have shown that quercetin has beneficial therapeutic effects in various human diseases, including diabetes. Quercetin has significant anti-diabetic effects and may be helpful in lowering blood sugar and increasing insulin sensitivity. Quercetin appears to affect many factors and signaling pathways involved in insulin resistance and the pathogenesis of type 2 of diabetes. TNFα, NFKB, AMPK, AKT, and NRF2 are among the factors that are affected by quercetin. In addition, quercetin can be effective in preventing and ameliorating the diabetic complications, including diabetic nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy, and affects the key mechanisms involved in the pathogenesis of these complications. These positive effects of quercetin may be related to its anti-inflammatory and anti-oxidant properties. In this article, after a brief review of the pathogenesis of insulin resistance and type 2 diabetes, we will review the latest findings on the anti-diabetic effects of quercetin with a molecular perspective. Then we will review the effects of quercetin on the key mechanisms of pathogenesis of diabetes complications including nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy. Finally, clinical trials investigating the effect of quercetin on diabetes and diabetes complications will be reviewed.

Potential Wound Healing Effect of Gel Based on Chicha Gum, Chitosan, and Mauritia flexuosa Oil

Wounds are considered a clinically critical issue, and effective treatment will decrease complications, prevent chronic wound formation, and allow rapid healing. The development of products based on naturally occurring materials is an efficient approach to wound healing. Natural polysaccharides can mimic the extracellular matrix and promote cell growth, thus making them attractive for wound healing. In this context, the aim of this work was to produce a gel based on chicha gum, chitosan, and Mauritia flexuosa oil (CGCHO) for wound treatment. TG and DTG analyzed the thermal behavior of the materials, and SEM investigated the surface roughness. The percentages of total phenolic compounds, flavonoids, and antioxidants were determined, presenting a value of 81.811 ± 7.257 µmol gallic acid/g Mauritia flexuosa oil, 57.915 ± 0.305 µmol quercetin/g Mauritia flexuosa oil, and 0.379 mg/mL, respectively. The anti-inflammatory was determined, presenting a value of 10.35 ± 1.46% chicha gum, 16.86 ± 1.00% Mauritia flexuosa oil, 10.17 ± 1.05% CGCHO, and 15.53 ± 0.65% chitosan, respectively. The materials were tested against Gram-negative (Klebsiella pneumoniae) and Gram-positive (Staphylococcus aureus) bacteria and a fungus (Candida albicans). The CGCHO formulation showed better antimicrobial activity against Gram-positive bacteria. In addition, an in vivo wound healing study was also performed. After 21 days of treatment, the epidermal re-epithelialization process was observed. CGCHO showed good thermal stability and roughness that can help in cell growth and promote the tissue healing process. In addition to the good results observed for the antimicrobial, antioxidant, anti-inflammatory activities and providing wound healing, they provided the necessary support for the healing process, thus representing a new approach to the wound healing process.

The Effect of Eurycoma longifolia Jack Tongkat Ali Hydrogel on Wound Contraction and Re-Epithelialization in In Vivo Excisional Wound Model

BACKGROUND: Wound management is one of the significant health problems throughout the world. Medicinal plants have been used widely in wound management. Eurycoma longifolia Jack which is known as Tongkat Ali (TA) is a tropical medicinal plant in South East Asian countries. AIM: The aim of the study was to investigate the effect of (TA) hydrogel on wound contraction and re-epithelialization in excisional wound model in rats. METHODS: Twenty male Sprague Dawley rats were divided into four groups each group contained five rats (n = 5). Animal treatment groups are formed as: Untreated (−ve) control, Hydrocyn® aqua gel (+ve), vehicle hydrogel, and (TA) hydrogel. A full-thickness circular excisional wound was created on the dorsal back of each rat. The wounded area was measured and photographed on days 3, 6, 9, 12, 15, and 18 post wounding to determine the percentage of wound contraction and re-epithelialization. RESULTS: (TA) hydrogel showed significant increase in the percentage of wound contraction by 43.38% compared with the other groups (p = 0.032, p < 0.050) during the first interval (inflammatory phase). Although in the later healing stages (proliferative and remodeling) and re-epithelialization, our test group (TA) hydrogel did not show statistically difference with the other groups yet it was comparable to medically certified wound healing agent. CONCLUSION: (TA) hydrogel significantly accelerated the wound healing process during the early stage, the inflammatory stage. Whereas during the later healing stages and re-epithelialization, it showed almost the same effect of Hydrocyn® aqua gel.

Research Progress of Quercetin Delivery Systems

Quercetin is the main dietary flavonoid with a wide range of pharmacological activities. However, the poor gastrointestinal absorption and low bioavailability of quercetin curtails its clinical applications.. Enhancement the bioavailability of quercetin focuses on the application of delivery systems technologies such as microparticle delivery systems, solid dispersions, encapsulation, phospholipid complexes, and hydrogels , which have been systematically reviewed .And theirapplications in vitro and in vivo animal experiments also been described, promoting the development and optimization of drug delivery system for clinical applications.

Molecular Insights on the Therapeutic Effect of Selected Flavonoids on Diabetic Neuropathy

One of the common clinical complications of diabetes is diabetic neuropathy affecting the nervous system. Painful diabetic neuropathy is widespread and highly prevalent. At least 50% of diabetes patients develop diabetic neuropathy eventually. The four main types of diabetic neuropathy are peripheral neuropathy, autonomic neuropathy, proximal neuropathy (diabetic polyradiculopathy), and mononeuropathy (Focal neuropathy). Glucose control remains the common therapy for diabetic neuropathy due to limited knowledge on early biomarkers that are expressed during nerve damage, thereby limiting the cure through pharmacotherapy. Glucose control dramatically reduces the onset of neuropathy in type 1 diabetes but proves less effective in type 2 diabetes. Therefore, the focus is on various herbal remedies for prevention and treatment. There is numerous research on the use of anticonvulsants and antidepressants for the management of pain in diabetic neuropathy. Extensive research is being done on natural products including the isolation of pure compounds like flavonoids from plants and their effect on diabetic neuropathy. This review focuses on the use of an important of flavonoids such as flavanols (e.g., quercetin, rutin, kaempferol, and isorhamnetin), flavanones (e.g., hesperidin, naringenin and c,lass eriodictyol), and flavones (e.g., apigenin, luteolin, tangeretin, chrysin, and diosmin) for the prevention and treatment of diabetic neuropathy. The mechanisms of action of flavonoids against diabetic neuropathy by their antioxidant, anti-inflammation, anti-glycation properties, etc. are also covered in this review article.

Dual drug delivery collagen vehicles for modulation of skin fibrosisin vitro

Single molecule drug delivery systems have failed to yield functional therapeutic outcomes, triggering investigations into multi-molecular drug delivery vehicles. In the context of skin fibrosis, although multi-drug systems have been assessed, no system has assessed molecular combinations that directly and specifically reduce cell proliferation, collagen synthesis and transforming growth factor β1 (TGFβ1) expression. Herein, a core-shell collagen type I hydrogel system was developed for the dual delivery of a TGFβ trap, a soluble recombinant protein that inhibits TGFβ signalling, and Trichostatin A (TSA), a small molecule inhibitor of histone deacetylases. The antifibrotic potential of the dual delivery system was assessed in an in vitro skin fibrosis model induced by macromolecular crowding (MMC) and TGFβ1. SDS-PAGE and HPLC analyses revealed that ~ 50 % of the TGFβ trap and ~ 30 % of the TSA were released from the core and shell compartments, respectively, of the hydrogel system after 10 days (longest time point assessed) in culture. As a direct consequence of this slow release, the core (TGFβ trap) / shell (TSA) hydrogel system induced significantly (p < 0.05) lower than the control group (MMC and TGFβ1) collagen type I deposition (assessed via SDS-PAGE and immunocytochemistry), α smooth muscle actin (αSMA) expression (assessed via immunocytochemistry) and cellular proliferation (assessed via DNA quantification) and viability (assessed via calcein AM and ethidium homodimer-I staining) after 10 days in culture. On the other hand, direct TSA-TGFβ supplementation induced the lowest (p < 0.05) collagen type I deposition, αSMA expression and cellular proliferation and viability after 10 days in culture. Our results illustrate the potential of core-shell collagen hydrogel systems for sustained delivery of antifibrotic molecules.

Reveals of quercetin's therapeutic effects on oral lichen planus based on network pharmacology approach and experimental validation

Oral lichen planus (OLP) is a localized autoimmune disease of the oral mucosa, with an incidence of up to 2%. Although corticosteroids are the first-line treatment, they cause several adverse effects. Quercetin, a naturally occurring compound, has fewer side-effects and provides long-term benefits. Besides, it has powerful anti‑inflammatory activities. Here, we combined network pharmacology with experimental verification to predict and verify the key targets of quercetin against OLP. First, 66 quercetin-OLP common targets were analyzed from various databases. The protein–protein interaction (PPI) network was constructed. Topology analysis and MCODE cluster analysis of common targets were conducted to identify 12 key targets including TP53, IL-6 and IFN-γ and their connections. Gene functions and key signaling pathways, including reactive oxygen species metabolism, IL-17 pathway and AGE-RAGE pathway, were enriched by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Then, in vitro experiments showed that quercetin interfered with Th1/Th2 balance by acting on IL-6 and IFN-γ to modulate the immune system in treating OLP. Quercetin considerably affected the apoptosis and migration of T lymphocytes in OLP patients. Our study reveals the potential therapeutic targets and signaling pathways of quercetin associated with OLP, and establishes the groundwork for future clinical applications.

High-Intensity, Low-Frequency Pulsed Electromagnetic Field as an Odd Treatment in a Patient with Mixed Foot Ulcer: A Case Report

Lower-extremity ulcers are associated with an increasing prevalence and significant economic and social costs. To date, there is no high-quality evidence related to an optimal treatment algorithm. A multimodal approach is needed particularly in patients with comorbidity and polytherapy. Herein, we report the case of a 94-year-old Caucasian female with comorbidity and polytherapy who was admitted to our observation for a history (1 year) of chronic painful malleolar mixed ulcer. After clinical evaluation, she was treated with a twice daily pain relief therapy and with a weekly diamagnetic therapy protocol plus a local treatment. During the clinical examination, we documented a statistically significant improvement in both pain (VAS score from 8 to 2 p < 0.01) and foot ulcer (surface reduction from 6 cm × 4 cm to 2 cm × 2 cm, p < 0.01) at the sixth week of combined treatment. The ulcer completely healed at the ninth week. This is the first study to document the effect of diamagnetic therapy as an add-on therapy in the management of wound healing. In conclusion, even if high-quality evidence is still lacking, diamagnetic therapy might represent an interesting option as an add-on treatment for ulcer.

Modern Nanocarriers as a Factor in Increasing the Bioavailability and Pharmacological Activity of Flavonoids

This review is devoted to modern systems of nanocarriers that ensure the targeted delivery of flavonoids to various organs and systems. Flavonoids have wide range of effects on the human body due to their antioxidant, anti-inflammatory, antitumor, antimicrobial, antiplatelet and other types of activity. However, the low bioavailability of flavonoids significantly limits their practical application. To overcome this disadvantage, serious efforts have been made in recent years to develop nanoscale carriers for flavonoids. This is particularly important in view of the known antitumor effect of these compounds, which allows them to target tumor cells without affecting surrounding healthy tissues. Nanocarriers provide increased penetration of biologicals into specific organs in combination with controlled and prolonged release, which markedly improves their effectiveness. This review summarizes data on the use of phytosomes, lipid-based nanoparticles, as well as polymeric and inorganic nanoparticles; their advantages and drawbacks are analyzed; the prospect of their use is discussed that opens new possibilities for the clinical application of flavonoids.

Pharmacological Efficacy of Tamarix aphylla: A Comprehensive Review

Tamarix aphylla is a well-known species of the genus Tamarix. T. aphylla (Tamaricaceae) is a perennial tree in Asia, the Middle East, and Central Africa. It is used as a carminative diuretic in tuberculosis, leprosy, and hepatitis. Various pharmacological properties have been shown by T. aphylla, such as antidiabetic, anti-inflammatory, antibacterial, antifungal, anticholinesterase, and wound-healing activity. However, T. aphylla has not received much attention for its secondary metabolites and bioactive constituents. Research has shown that this plant has hidden potential that needs to be explored. This review aims to cover botanical classification, geographical distribution, taxonomy, ethnobotanical uses, and the phytochemical compounds found in T. aphylla. The toxicology and pharmacological effects of T. aphylla are also discussed. We examined various scholarly resources to gather information on T. aphylla, including Google Scholar, Scopus, Science Direct, Springer Link, PubMed, and Web of Science. The finding of this work validates a connection between T. aphylla in conventional medicine and its antidiabetic, antibacterial, anti-inflammatory, wound-healing, antifungal, anticholinesterase, and other biological effects. T. aphylla's entire plant (such as bark, leaves, fruits) and root extracts have been used to treat hypertension, stomach discomfort, hair loss, cough and asthma, abscesses, wounds, rheumatism, jaundice, fever, tuberculosis, and gum and tooth infection. The phytochemical screening revealed that noticeably all extracts were devoid of alkaloids, followed by the presence of tannins. In addition, different parts have revealed the existence of steroids, flavonoids, cardiac glycosides, and byproducts of gallic acid and ellagic acid. T. aphylla has shown many valuable activities against different diseases and supports its traditional uses. Therefore, high-quality preclinical research and well-designated clinical trials are needed to establish the efficacy and safety of this plant in humans.

The senescence-associated secretory phenotype: Fueling a wound that never heals

Wound healing is impaired with advanced age and certain chronic conditions, such as diabetes and obesity. Moreover, common cancer treatments, including chemotherapy and radiation, can cause unintended tissue damage and impair wound healing. Available wound care treatments are not always effective, as some wounds fail to heal or recur after treatment. Hence, a more thorough understanding of the pathophysiology of chronic, nonhealing wounds may offer new ideas for the development of effective wound care treatments. Cancers are sometimes referred to as wounds that never heal, sharing mechanisms similar to wound healing. We describe in this review how cellular senescence and the senescence-associated secretory phenotype (SASP) contribute to chronic wounds versus cancer.

The Role of Antioxidants on Wound Healing: A Review of the Current Evidence

(1) Background: Reactive oxygen species (ROS) play a crucial role in the preparation of the normal wound healing response. Therefore, a correct balance between low or high levels of ROS is essential. Antioxidant dressings that regulate this balance are a target for new therapies. The purpose of this review is to identify the compounds with antioxidant properties that have been tested for wound healing and to summarize the available evidence on their effects. (2) Methods: A literature search was conducted and included any study that evaluated the effects or mechanisms of antioxidants in the healing process (in vitro, animal models or human studies). (3) Results: Seven compounds with antioxidant activity were identified (Curcumin, N-acetyl cysteine, Chitosan, Gallic Acid, Edaravone, Crocin, Safranal and Quercetin) and 46 studies reporting the effects on the healing process of these antioxidants compounds were included. (4) Conclusions: this review offers a map of the research on some of the antioxidant compounds with potential for use as wound therapies and basic research on redox balance and oxidative stress in the healing process. Curcumin, NAC, quercetin and chitosan are the antioxidant compounds that shown some initial evidence of efficacy, but more research in human is needed.

Compendium of Conventional and Targeted Drug Delivery Formulation Used for the Treatment and Management of the Wound Healing

Wound healing is a complex and dynamic phenomenon that involves the restoration of normal physiology and functioning of injured tissue. The process of wound healing is primarily regulated by various cytokines, inflammatory mediators, and growth factors at the molecular level. Any intervention in the normal wound healing process leads to further tissue damage, which in turn leads to delayed wound healing. Several natural, synthetic drugs and their combinations were used to restored and accelerate the wound healing process. However, the conventional delivery carriers were not much effective, and thus, nowadays, nanocarriers are gaining much popularity since they are playing a pivotal role in drug delivery. Since nanocarriers have their own applicability and benefits (enhance the bioavailability, site-specific targeting) so, they can accelerate wound healing more efficiently. This review briefly discussed about the various events that take place during the wound healing process with emphasis on various natural, synthetic, and combination drug therapy used for accelerating wound healing and the role of nanotechnology-based approaches in chronic wound healing.

Nanomaterials in Skin Regeneration and Rejuvenation

Skin is the external part of the human body; thus, it is exposed to outer stimuli leading to injuries and damage, due to being the tissue mostly affected by wounds and aging that compromise its protective function. The recent extension of the average lifespan raises the interest in products capable of counteracting skin related health conditions. However, the skin barrier is not easy to permeate and could be influenced by different factors. In the last decades an innovative pharmacotherapeutic approach has been possible thanks to the advent of nanomedicine. Nanodevices can represent an appropriate formulation to enhance the passive penetration, modulate drug solubility and increase the thermodynamic activity of drugs. Here, we summarize the recent nanotechnological approaches to maintain and replace skin homeostasis, with particular attention to nanomaterials applications on wound healing, regeneration and rejuvenation of skin tissue. The different nanomaterials as nanofibers, hydrogels, nanosuspensions, and nanoparticles are described and in particular we highlight their main chemical features that are useful in drug delivery and tissue regeneration.

Update of Topical Interventions for Healing Diabetic Ulcers-A Systematic Review

There are a variety of dressings for wound healing. For this reason, research can assist in the choice and proper use of the intervention. This current view of the effectiveness of dressing on diabetic foot ulcers (DFUs) in patients with type 2 diabetes mellitus. This study is a systematic review of clinical trials selected in 4 databases: PubMed, Scopus, Web of Science, and Cochrane. Studies without language restriction, published between 2009 and 2020, were included. The search resulted in the identification of 5651 articles, of which 58 met all inclusion criteria. Among these, 2 biomaterials (D-acellular dermal matrix and keratinocyte) and phenytoin were highlighted for achieving healing rates of 100% and 95.82% ± 2.22%, respectively. The literature presents several alternatives with different actions, cure rates, reduction rates, and varied cost benefits. The growth in the use of biomaterials for the treatment of DFU can be seen in this study.

Nanostructured lipid carriers containing chitosan or sodium alginate for co-encapsulation of antioxidants and an antimicrobial agent for potential application in wound healing

The high incidence and costs of chronic wounds in the elderly have motivated the search for innovations to improve product performance and the healing process while reducing costs. In this study, bioadhesive nanostructured lipid carriers (NLC) were developed for the co-encapsulation of compounds with antioxidant (α-tocopherol and quercetin) and antimicrobial (tea tree oil) activity for management of wounds. The NLC was produced with shea butter and argan oil, and modified with sodium alginate or chitosan to confer bioadhesive properties. Spherical nanoparticles of ~307-330 nm and zeta potential varying from -21.2 to +11.8 mV were obtained. Thermal analysis demonstrated that the lipid matrix reduced tea tree oil thermal loss (~1.8-fold). Regardless of the type of polysaccharide employed, the NLCs promoted cutaneous localization of antioxidants in damaged (subjected to incision) skin, with a ~74 to 180-fold higher delivery into the skin compared to percutaneous delivery. This result is consistent with the similar bioadhesive properties of chitosan or sodium alginate-modified NLC. Nanoencapsulation of tea tree oil did not preclude its antimicrobial effects against susceptible and resistant strains of S. aureus and P. aeruginosa, while co-encapsulation of antioxidants increased the NLC-induced fibroblasts migration, supporting their potential usefulness for management of wounds.

The Intestinal Fatty Acid-Enteroendocrine Interplay, Emerging Roles for Olfactory Signaling and Serotonin Conjugates

Intestinal enteroendocrine cells (EECs) respond to fatty acids from dietary and microbial origin by releasing neurotransmitters and hormones with various paracrine and endocrine functions. Much has become known about the underlying signaling mechanisms, including the involvement of G-protein coupled receptors (GPCRs), like free fatty acids receptors (FFARs). This review focusses on two more recently emerging research lines: the roles of odorant receptors (ORs), and those of fatty acid conjugates in gut. Odorant receptors belong to a large family of GPCRs with functional roles that only lately have shown to reach beyond the nasal-oral cavity. In the intestinal tract, ORs are expressed on serotonin (5-HT) and glucagon-like-peptide-1 (GLP-1) producing enterochromaffin and enteroendocrine L cells, respectively. There, they appear to function as chemosensors of microbiologically produced short-, and branched-chain fatty acids. Another mechanism of fatty acid signaling in the intestine occurs via their conjugates. Among them, conjugates of unsaturated long chain fatty acids and acetate with 5-HT, N-acyl serotonins have recently emerged as mediators with immune-modulatory effects. In this review, novel findings in mechanisms and molecular players involved in intestinal fatty acid biology are highlighted and their potential relevance for EEC-mediated signaling to the pancreas, immune system, and brain is discussed.

Quercetin-Conjugated Superparamagnetic Iron Oxide Nanoparticles Protect AlCl3-Induced Neurotoxicity in a Rat Model of Alzheimer's Disease via Antioxidant Genes, APP Gene, and miRNA-101

Alzheimer's disease (AD) is a neurodegenerative disease with cognitive impairment. Oxidative stress in neurons is considered as a reason for development of AD. Antioxidant agents such as quercetin slow down AD progression, but the usage of this flavonoid has limitations because of its low bioavailability. We hypothesized that quercetin-conjugated superparamagnetic iron oxide nanoparticles (QT-SPIONs) have a better neuroprotective effect on AD than free quercetin and regulates the antioxidant, apoptotic, and APP gene, and miRNA-101. In this study, male Wistar rats were subjected to AlCl3, AlCl3 + QT, AlCl3 + SPION, and AlCl3 + QT-SPION for 42 consecutive days. Behavioral tests and qPCR were used to evaluate the efficiency of treatments. Results of behavioral tests revealed that the intensity of cognitive impairment was decelerated at both the middle and end of the treatment period. The effect of QT-SPIONs on learning and memory deficits were closely similar to the control group. The increase in expression levels of APP gene and the decrease in mir101 led to the development of AD symptoms in rats treated with AlCl3 while these results were reversed in the AlCl3 + QT-SPIONs group. This group showed similar results with the control group. QT-SPION also decreased the expression levels of antioxidant enzymes along with increases in expression levels of anti-apoptotic genes. Accordingly, the antioxidant effect of QT-SPION inhibited progression of cognitive impairment via sustaining the balance of antioxidant enzymes in the hippocampus of AD model rats.

Opening eyes to therapeutic perspectives of bioactive polyphenols and their nanoformulations against diabetic neuropathy and related complications

Introduction: Diabetic neuropathy (DN) is one of the major complications arising from hyperglycaemia in diabetic patients. In recent years polyphenols present in plants have gained attention to treat DN. The main advantages associated with them are their action via different molecular pathways to manage DN and their safety. However, they failed to gain clinical attention due to challenges associated with their formulation development such as lipophilicity,poor bioavailability, rapid systemic elimination, and enzymatic degradation.Area covered: This article includes different polyphenols that have shown their potential against DN in preclinical studies and the research carried out towards development of their nanoformulations in order to overcome aforementioned issues.Expert opinion: In this review various polyphenol based nanoformulations such as nanospheres, self-nanoemulsifying drug delivery systems, niosomes, electrospun nanofibers, metallic nanoparticles explored exclusively to treat DN are discussed. However, the literature available related to polyphenol based nanoformulations to treat DN is limited. Moreover, these experiments are limited to preclinical studies. Hence, more focus is required towards  development of nanoformulations using simple and single step process as well as inexpensive and non-toxic excipients so that a stable, scalable, reproducible and non-toxic formulation could be achieved and clinical trials could be initiated.

Nanotechnology-driven advances in the treatment of diabetic wounds

Diabetic foot ulcers (DFUs) are chronic severe complications of diabetes disease and remain a worldwide clinical challenge with social and economic consequences. Diabetic wounds can cause infection, amputation of lower extremities, and even death. Several factors including impaired angiogenesis, vascular insufficiency, and bacterial infections result in a delayed process of wound healing in diabetic patients. Treatment of wound infections using traditional antibiotics has become a critical status. Thus, finding new therapeutic strategies to manage diabetic wounds is urgently needed. Nanotechnology has emerged as an efficient approach for this purpose. This review aimed to summarize recent advances using nanotechnology for the treatment of diabetic wounds.

Hydrogels for the Delivery of Plant-Derived (Poly)Phenols

This review deals with hydrogels as soft and biocompatible vehicles for the delivery of plant-derived (poly)phenols, compounds with low general toxicity and an extraordinary and partially unexplored wide range of biological properties, whose use presents some major issues due to their poor bioavailability and water solubility. Hydrogels are composed of polymeric networks which are able to absorb large amounts of water or biological fluids while retaining their three-dimensional structure. Apart from this primary swelling capacity, hydrogels may be easily tailored in their properties according to the chemical structure of the polymeric component in order to obtain smart delivery systems that can be responsive to various internal/external stimuli. The functionalization of the polymeric component of hydrogels may also be widely exploited to facilitate the incorporation of bioactive compounds with different physicochemical properties into the system. Several prototype hydrogel systems have been designed for effective polyphenol delivery and potential employment in the treatment of human diseases. Therefore, the inherent features of hydrogels have been the focus of considerable research efforts over the past few decades. Herein, we review the most recent advances in (poly)phenol-loaded hydrogels by analyzing them primarily from the therapeutic perspective and highlighting the innovative aspects in terms of design and chemistry.

Isolation and Purification of Glucans from an Italian Cultivar of Ziziphus jujuba Mill. and In Vitro Effect on Skin Repair

Glucans possess a broad spectrum of biological activities. In this context, the present study was performed to isolate glucans from an Italian cultivar of Ziziphus jujuba Mill. at three different harvesting periods, in order to evaluate their effects on wound healing. The dry fruits were subjected to an alkaline extraction and then isolated glucans were purified by dialyzation. The crude and soluble samples were characterized by FT-IR and SEM analyses. Afterwards, total, α- and β-glucan content was measured using an enzymatic procedure. The results highlighted that the glucan amount increased as the maturation proceeded as well as the β-glucan percentage, which ranged from 48.2 at the first harvesting to 65.4 at the third harvesting. Furthermore, the effects of isolated glucans on the viability and migration of keratinocytes were evaluated using the in vitro MTT and scratch wound assays. The best proliferative effects on keratinocyte migration have been achieved with soluble glucans from third harvesting at 100 μM after 24 and 48 h (*** P < 0.001). The same treated group showed significant narrowing of the scratch area after 24 h and complete closure of the injury after 48 h. The findings highlighted the effectiveness of soluble glucans on regeneration of damaged skin.