The effect of combined photobiomodulation and curcumin on skin wound healing in type I diabetes in rats

Tailoring photobiomodulation to enhance tissue regeneration

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Animal models for type 1 and type 2 diabetes: advantages and limitations

Diabetes mellitus, commonly referred to as diabetes, is a group of metabolic disorders characterized by chronic elevation in blood glucose levels, resulting from inadequate insulin production, defective cellular response to extracellular insulin, and/or impaired glucose metabolism. The two main types that account for most diabetics are type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), each with their own pathophysiological features. T1D is an autoimmune condition where the body's immune system attacks and destroys the insulin-producing beta cells in the pancreas. This leads to lack of insulin, a vital hormone for regulating blood sugar levels and cellular glucose uptake. As a result, those with T1D depend on lifelong insulin therapy to control their blood glucose level. In contrast, T2DM is characterized by insulin resistance, where the body's cells do not respond effectively to insulin, coupled with a relative insulin deficiency. This form of diabetes is often associated with obesity, sedentary lifestyle, and/or genetic factors, and it is managed with lifestyle changes and oral medications. Animal models play a crucial role in diabetes research. However, given the distinct differences between T1DM and T2DM, it is imperative for researchers to employ specific animal models tailored to each condition for a better understanding of the impaired mechanisms underlying each condition, and for assessing the efficacy of new therapeutics. In this review, we discuss the distinct animal models used in type 1 and type 2 diabetes mellitus research and discuss their strengths and limitations.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

Bibliometric Analysis to Global Research Status Quo on Photobiomodulation

Background: Photobiomodulation (PBM) becomes a remedial technology with growing popularity. The primary goal of this article is to conduct a PBM literature review, providing an overall systematic understanding of current and future trends. Methods: A dataset was made with topic retrieval, concerning PBM research retrieved from the Web of Science Core Collection. We analyzed to forecast research frontiers in this field using the softwares: VOSviewer, CiteSpace, and Biblioshiny. Results: Four thousand five hundred thirty pieces of literature were retrieved from our database. Current trends were characterized by keywords of "light," "spinal cord injury," "skeletal muscle," and so on. Future trends were characterized probably by six cutting-edge terms: "wound healing," "pain," "oral mucositis," "Alzheimer's disease," "Parkinson's disease," and "orthodontics." Conclusions: This study finds that the inadequacy of in-depth reliable interpretation of current clinical data calls for molecular biological mechanisms together with well-designed, large-sample, multicenter clinical trials. The study of oral, wound, and neural-related mechanisms and the exploration of therapeutic effects may be the popular trend at present and in the next few years.

Bioinspired Platelet-Anchored Electrospun Meshes for Tight Inflammation Manipulation and Chronic Diabetic Wound Healing

Tight manipulation of the initial leukocytes infiltration and macrophages plasticity toward the M2 phenotype remain a challenge for diabetic wound healing. Inspired by the platelet function and platelet-macrophage interaction, a platelet-anchored polylactic acid-b-polyethylene glycol-b-polylactic acid (PLA-PEG-PLA) electrospun dressing is developed for inflammatory modulation and diabetic wounds healing acceleration. PLA-PEG-PLA electrospun meshes encapsulated with thymosin β4 (Tβ4) and CaCl2 is fabricated with electrospinning, followed by immersion of electrospun mesh in platelet-rich plasma to firmly anchor the platelets. It is demonstrated that the anchored platelets on electrospun mesh can enhance the initial macrophage recruitment and control the Tβ4 release from electrospun meshes to facilitate the macrophages polarization to the M2 phenotype. The inflammatory regulation promotes the expression of vascular endothelial growth factor and the migration of vascular endothelial cells for angiogenesis, resulting in accelerated diabetic wounds healing. Therefore, this work paved a new way to design platelet-inspired electrospun meshes for inflammation manipulation and diabetic wound healing.

Physical therapy in diabetic foot ulcer: Research progress and clinical application

Diabetes foot ulcer (DFU) is one of the most intractable complications of diabetes and is related to a number of risk factors. DFU therapy is difficult and involves long-term interdisciplinary collaboration, causing patients physical and emotional pain and increasing medical costs. With a rising number of diabetes patients, it is vital to figure out the causes and treatment techniques of DFU in a precise and complete manner, which will assist alleviate patients' suffering and decrease excessive medical expenditure. Here, we summarised the characteristics and progress of the physical therapy methods for the DFU, emphasised the important role of appropriate exercise and nutritional supplementation in the treatment of DFU, and discussed the application prospects of non-traditional physical therapy such as electrical stimulation (ES), and photobiomodulation therapy (PBMT) in the treatment of DFU based on clinical experimental records in ClinicalTrials.gov.

Effect of combination of photobiomodulation 904 nm superpulsed laser therapy and Hippophae rhamnoides L. on third-degree burn wound healing

BACKGROUND

Burn is a traumatic injury and aesthetic scarless repair poses a great challenge in area of cosmetic dermatology. Focus on multimode therapeutic strategies to promote healing of burns by regulating various stages of healing is warranted. Photobiomodulation therapy (PBMT), a non-invasive modality grabs the attention to repair impaired wounds. Seabuckthorn extract (SBTL-ALE) is known to possess antioxidant, anti-inflammation, and tissue-repair abilities. Current study aims to assess the effect of combination treatment of PBM 904 nm superpulsed laser and SBTL-ALE (2.5%) on repair of third-degree burn in rats.

METHODS

Rats were randomized into five groups: uninjured, control, SBTL-ALE, 904 nm PBMT, and combination. A transdermal burn wound was induced on the dorsal side of rats of all groups except the uninjured group and respective treatment was applied for 7 days postwounding.

RESULTS

Dual treatment increased wound area contraction compared to control and either treatment alone. Immunohistochemical analyses exhibited increased angiogenesis, dermal hydration, collagen synthesis, and maintained redox homeostasis as evidenced by enhanced expression (p < 0.05) of CD31, aquaporin3, collagen type 3, Nrf2, and HO1 in combination group compared with control. Conversely, pro-inflammatory and oxidative stress markers exhibited reduced (p < 0.05) TNF-α, IL-6, IL-1β, NOS-2, ROS levels, and increased catalase activity in combined treatment. Furthermore, energy metabolizing enzymes viz. citrate synthase, CCO, and ATP contents were substantially (p < 0.05) increased, and LDH activity was reduced in the combination group.

CONCLUSIONS

Dual treatment (PBMT + SBTL-ALE) prominently accelerates third-degree burn wound healing in rats, which could pave the path for multimode therapeutic strategies for the management of burns and dermal cosmetic care.

Photomodulative effects of low-level laser therapy on tracheal fenestration developed in in vivo model

The effect of low-level laser therapy (LLLT) on variable mucosal lesions in the upper aerodigestive tract has been reported. However, the effect of LLLT on tracheostomy sites or tracheal fenestration is rarely reported. In this study, we evaluate the effect of LLLT performed using 635 nm laser light based on a cylindrical diffuser and an animal model with tracheal fenestration. An animal model of tracheal fenestration is developed by suturing the trachea to the skin after performing a vertical tracheostomy from the second to the fifth tracheal ring of Wistar rats (male, body weight 200-250 g). LLLT (spot size: 2 cm²) is conducted once daily for five days using a handheld cylindrical device. Twenty-four rats are randomly assigned to a no-therapy or LLLT group with an energy density of 20 J/cm². Histological analysis is performed at 7 and 14 days after tracheal fenestration. Irradiation at the tracheal fenestration site with an energy density of 20 J/cm² improves the wound healing, as shown at 2 weeks after tracheostomy. Histological analysis shows significantly decreased acute inflammation and granulation tissue, as well as better cartilage regeneration and less tracheal wall thickening. Therefore, LLLT demonstrates therapeutic potential for preventing tracheal stenosis and granuloma after tracheostomy.

Biocompatible curcumin coupled nanofibrous membrane for pathogens sterilization and isolation

Airborne transmission of pathogens is the most probable cause for the spread of respiratory diseases, which can be intercepted by personal protective equipment such as masks. In this study, an efficient antiviral personal protective filter was fabricated by coupling the biocompatible curcumin (CCM) with nanofibrous polytetrafluoroethylene (PTFE) membrane. The CCM extracted from plants was first dissolved in acidified ethanol at a certain pH and temperature to optimize its loading concentration, antiviral activation, and binding forces on the polyethylene terephthalate (PET) support to form a pre-filtration layer at the front section of the filter. Ultrathin PTFE membrane was then fabricated on the antibacterial-antiviral PET support (A-A PET) by controllable heating lamination. This functional layer of the filter exhibits good gas permeance (3423.6 m³/(m²·h·kPa)) and ultrafine particles rejection rate (>98.79%). Moreover, the obtained A-A filter exhibit a high antibacterial rate against a variety of bacteria (E. coli, B. subtilis, A. niger, and Penicillium were 99.84%, 99.02%, 93.60%, 95.23%, respectively). Forthwith virucidal (SARS-CoV-2) efficiency of the A-A filter can reach 99.90% for 5 min. The filter shows good stability after 10 heating cycles, demonstrating its reusability.

Investigation of wound healing potential of photo-active curcumin-ZnO-nanoconjugates in excisional wound model

Wound healing, being a dynamic process consisting of hemostasis, inflammation, proliferation, and remodeling, involves the complicated interplay of various growth mediators and the cells associated repair system. Current wound healing therapies usually fail to completely regain skin integrity and functionality. Traditionally, curcumin is considered a potent natural wound healing agent as it possesses antibacterial, antioxidant, and anti-inflammatory properties. It is also known that zinc oxide (ZnO) nanoparticles (NPs) have photocatalytic properties, including the generation of reactive oxygen species. ZnO nanoaprticles are also Food and Drug Administration (FDA) approved as safe substances. While ZnO oxide requires illumination with ultraviolet light to become photocatalytically active, dye-sensitized ZnO can be activated by illumination with visible light. In the present study, we explored the wound healing potential of ZnO nanoparticles sensitized with curcumin (Cu+ZnO Nps) and illuminated with visible (blue) light generated by an array of high power LEDs. We studied the antibacterial effect of our conjugates by percentage reduction in bacterial growth and biofilm formation. The wound healing potential was analyzed by percentage wound contraction, biochemical parameters, and histopathological analysis of the wounded site. Additionally, angiogenesis and wound associated cytokines was evaluated by immunohistochemistry of CD31 and gene expression analysis of IL-1β, TNF-α, and MMP-9 after 16 days of post-wound treatment, respectively. Our study suggests that the therapeutic effect of Cu+ZnO NPs with LED illumination increases its wound healing potential by producing an antibacterial and anti-inflammatory effect. Moreover, the treatment strategy of using a nano formulation in combination with LED illumination further increases its efficacy. It was concluded that the anti-inflammatory and bactericidal effects of the LED illuminated Cu+ZnO Np showed accelerated wound healing with increased wound contraction, collagen deposition, angiogenesis, and re-epithelialization.

Antibacterial Effects of Commiphora gileadensis Methanolic Extract on Wound Healing

Commiphora gileadensis (CG) is a small tree distributed throughout the Middle East. It was traditionally used in perfumes in countries in this area. In Saudi Arabia, it was used to treat wounds burns and as an antidote to scorpion stings. This study aimed to evaluate the antimicrobial activity and cutaneous wound healing efficiency of the CG extracts using microbiological tests, rate of wound contraction and histopathological changes. CG plant were extracted using the methanol extraction technique; then, the methanolic extract was characterized using liquid chromatography coupled with mass spectrometry (LC−MS). Afterwards, a six-millimetre (mm) excision wound was induced in 60 male Balb/c mice. Mice were classified into two classes; each class consisted of three groups of 10 mice. In the non-infected wound class, the group I was assigned as control and received normal saline. Group II received gentamicin treatment, and group III treated with CG-methanolic extract. In the Staphylococcus aureus-infected class, group IV received normal saline, and groups V and VI were treated with gentamicin and CG-methanolic extract, respectively. The colonization of infected wounds was determined using colony-forming units (CFUs), and the percentage of wound contraction was measured in all groups. Finally, the histopathologic semi-quantitative determination of wound healing was evaluated by inflammatory cell infiltration, the presence of collagen fibres and granulation tissue, and the grade of re-epithelization. Composition analysis of the methanolic extract confirmed the presence of a high amount of ceramide (69%) and, to a lesser extent, hexosylceramide (18%) and phosphatidylethanolamine (7%) of the total amount. Additionally, there was a statistically significant difference between the percentage of wound contraction in the CG-treated and control groups in both Staphylococcus aureus-infected and non-infected wounds (p < 0.01). The colonization of the infected wounds was lower in the group treated with CG than in the control group (p < 0.01). In both non-infected and infected wounds, the CG-treated group showed significant statistical differences in inflammatory cell infiltration, collagen fibres, re-epithelization and granulation tissue formation compared with the control group (p < 0.01). The CG extract possesses antibacterial and anti-inflammatory properties that induce wound healing.

Localized delivery of curcumin by thermosensitive hydrogels for promoting wound healing

BACKGROUND

Curcumin can promote wound healing, but its drug delivery medium needs to be improved further.

OBJECTIVES

A curcumin-loaded thermosensitive hydrogel was prepared, its characterization was evaluated, and its promoting effect on wound healing was observed.

METHODS

Curcumin-loaded thermosensitive hydrogels were prepared with different percentages of poloxamer 188 and poloxamer 407. A small tube inversion assay was used to observe the sol-gel transition temperature, and a rotational rheometer was used to detect the sol viscosity, sol-gel phase transition temperature and phase transition time. The microstructure of the gel was observed by scanning electron microscopy, and Fourier infrared spectroscopy was used to evaluate whether curcumin was successfully loaded. Finally, its promoting effect on wound healing was observed in vivo and in vitro.

RESULTS

Poloxamer 407 24% and poloxamer 188 1% were selected to prepare curcumin-loaded thermosensitive hydrogels. After 60 ± 15 s at 32 °C, the sol-gel transition process was completed, with certain elastic behavior and solid-like rheological properties. Scanning electron microscopy showed that the pores of the curcumin-P407/P188 thermosensitive hydrogel were interconnected, with an average pore size ranging from 5 to 10 μm. Hydrogels showed a higher swelling ratio. Fourier transform infrared spectroscopy showed that curcumin had been incorporated into the hydrogel. Live/dead cell assays suggested that the hydrogel was not toxic to fibroblasts. Curcumin-loaded thermosensitive hydrogels can promote an increase in S-phase fibroblasts and improve wound healing.

CONCLUSIONS

Curcumin-loaded P407/P188 thermosensitive hydrogel improves wound healing. More in-depth research is needed in the future.

Pretreatment with combined low-level laser therapy and methylene blue improves learning and memory in sleep-deprived mice

Low-level laser therapy (LLLT) and methylene blue (MB) were proved to have neuroprotective effects. In this study, we evaluated the preventive effects of LLLT and MB alone and in combination to examine their efficacy against sleep deprivation (SD)-induced cognitive impairment. Sixty Balb/c male mice were randomly divided into five groups as follows: wide platform (WP), SD, LLLT, MB, LMB (treatment with both LLLT and MB). Daily MB (0.5 mg/kg) was injected for ten consecutive days. An 810-nm, 10-Hz pulsed laser was used in LLLT every other day. We used the T-maze test, social interaction test (SIT), and shuttle box to assess learning and memory and PSD-95, GAP-43, and synaptophysin (SYN) markers to examine synaptic proteins levels in the hippocampus. Our results showed that SD decreased alternation rate in the T-maze test, sociability and social novelty in SIT, and memory index in the shuttle box. Single treatments were not able to reverse these in most of the behavioral parameters. However, behavioral tests showed a significant difference between combined therapy and the SD group. The levels of synaptic plasticity markers were also significantly reduced after SD. There was a significant difference between the MB group and SD animals in GAP-43 and SYN biomarkers. Combination treatment with LLLT and MB also increased GAP-43, PSD-95, and SYN compared to the SD group. We found that the combined use of LLLT and MB pretreatment is more effective in protecting SD-induced cognitive impairment, which may be imparted via modulation of synaptic proteins.

Development of plasma functionalized polypropylene wound dressing for betaine hydrochloride controlled drug delivery on diabetic wounds

Diabetes Mellitus is one of the most worrying issues among illnesses, and its chronic subsequences almost refer to inflammations and infections. The loading and local release of antioxidants to wounds may decrease inflammations. However, the low wettability of PolyPropylene (PP) restricts the drug from loading. So, to increase the adhesion of PP for loading an optimum amount of Betaine Hydrochloride (BET), plasma has been applied in two steps of functionalization and polymerization, which has been confirmed with FE-SEM, ATR-FTIR, and EDX. The new chemistry of the surface led to almost 80% of BET loaded. The drug-releasing ratio studied by HPLC approved the presence of a PEG-like layer, which was coated by polymerization of tetraglyme. To evaluate the wound healing potential of the application of PP meshes treated by plasma, 72 Wistar rats were subdivided into four groups. The skin injury site was removed and underwent biomechanical tests, stereological analysis, and RNA extraction. The results showed a significant improvement in the polymerized scaffold containing BET for skin injury. The present study suggests that the use of a modified PP mesh can induce tissue regeneration and accelerate wound healing at the skin injury site.

The Combined Effect of Photobiomodulation and Curcumin on Acute Skin Wound Healing in Rats

Introduction: Abnormal wound repair is a cause for considerable expense, as well as patient morbidity and mortality. Here, we investigated the combined impact of photobiomodulation (PBM) and curcumin on a rat experimental model of an acute skin wound. Methods: A round full-thickness wound was created on the back of each rat. We divided the rats into the following four groups. Group one was the control group. Group two received pulse wave (PW) PBM at a dose of 890 nm, 80 Hz, and 0.2 J/cm². Group 3 received 40 mg/kg curcumin by gastric gavage and group 4 were treated with PWPBM + curcumin. We measured the wound area on days 4, 7, and 15, and performed microbiological and tensiometric examinations. Results: There was markedly improved wound contraction in the curcumin (7.5 ± 0.57; P =0.000), PBM (8.5 ± 1.2; P =0.000), and PBM + curcumin (14.5 ± 4.3; P =0.002) groups relative to the control group (25 ± 6). PBM (100 ± 7.3; P =0.005), and PBM + curcumin (98 ± 6; P =0.005) groups meaningfully improved tensile strength relative to the control group (61 ± 8.2). On day 15, the PBM (10 ± 5; P =0.000), curcumin (14 ± 4.5, P =0.000), and PBM + curcumin (27.3 ± 8.3; P =0.000) groups meaningfully decreased microbial flora relative to the control group (95 ± 6). Conclusion: We concluded that the PBM and PBM + curcumin groups meaningfully accelerated wound healing of the acute skin wound in the rats. The results of the PBM group were statistically more effective than the curcumin alone and PBM + curcumin-treated groups.

Low-power lasers on bacteria: stimulation, inhibition, or effectless?

Clinical protocols based on low-power lasers have been widely used for inflammation process resolution improvement, pain relief, wound healing, and nerve regeneration. However, there are concerns if exposure to such lasers could have negative effects on infected organs and tissues. There are experimental data suggesting exposure to radiations emitted by low-power lasers either induces stimulation, inhibition, or it is effectless on bacterial cultures. Thus, this review aimed to carry out a review of studies and to propose a hypothesis to explain why exposure to low-power lasers could stimulate, inhibit, or have no effect on bacteria. A literature search was carried out for assessment of published reports on effect of low-power lasers on bacteria. The experimental data suggest that keys for determining laser-induced effects on bacteria are specific physical laser and biological parameters. Final consequence on bacterial cells could depend on exposure to low-power laser which could either cause more stimulation of endogenous photoacceptors, more excitation of endogenous photosensitizers, or a balance between such effects.

Near-infrared light II - assisted rapid biofilm elimination platform for bone implants at mild temperature

Light-triggered therapy is a prospective method to combat implant-associated infection but near-infrared I (NIR-I) light has insufficient penetrating ability in tissues and local hyperthermia induced by the photothermal treatment may destroy surrounding healthy tissues. Herein, a near-infrared II (NIR-II) phototherapy system composed of upconversion elements doped titanium dioxide nanorods (TiO₂ NRs)/curcumin (Cur)/hyaluronic acid (HA)/bone morphogenetic protein-2 (BMP-2) is designed for biomedical titanium and demonstrated to overcome the above hurdles simultaneously. Incorporation of F, Yb, and Ho not only improves the photocatalytic ability, but also renders the implants with the upconversion capability, so that the NRs can generate enough reactive oxygen species (ROS) when irradiated by the NIR-II laser. Furthermore, the combined actions of quorum sensing inhibitors, ROS, and physical puncture by NRs eliminate Staphylococcus aureus biofilms on titanium rapidly at a mild temperature of 45 °C by only requiring irradiation with the 1060 nm laser for only 15 min in vitro and in vivo. The presence of Cur mitigates the immune response and BMP-2 improves osteogenic differentiation, thus accelerating new bone formation. This low-temperature NIR-II light-triggered antibacterial platform has large potential in combating deep-tissue infection in clinical applications.

Folate-Targeted Curcumin-Encapsulated Micellar Nanosystem for Chemotherapy and Curcumin-Mediated Photodynamic Therapy

Curcumin (CUR) is a natural phenolic product used as a high-efficiency and low-toxicity anticancer drug and photosensitizer. However, it has a poor aqueous solubility and a lack of target specificity, which limits its clinical applications. Hence, we developed a folate-conjugated polymeric micelle to enhance the efficient delivery of CUR for effective cancer cell targeting and anticancer efficiency. A series of biocompatible folate-conjugated poly(2-(methacryloyloxy)ethylphosphoryl- choline)-b-poly(ε-caprolactone) (FPM) was synthesized with different hydrophobic lengths and folate contents. The prepared CUR-loaded micelles (CUR-FPM) possessed several superior properties, including an excellent drug loading capacity (6.3 ± 1.2%), improved CUR aqueous stability, fast-sustained CUR release in an acidic environment, and efficient intracellular production of reactive oxygen species. The in vitro cytotoxicity demonstrated that the CUR-FPM micelles efficiently suppressed the growth of HeLa cells (folate-receptor overexpression) compared to that of HT-29 cells, and a competition study showed less cytotoxic effect when free folic acid blocked the folate receptor, indicating the folate conjugation played the role of targeting the specific cells well. Moreover, the CUR-mediated photodynamic therapy (PDT) by CUR-FPM micelles under irradiation further inhibited the proliferation of cancer cells. All these results indicate that the CUR-FPM micelles could be a promising delivery system for folate-overexpressing cancer cells, complementary chemotherapy, and CUR-mediated photodynamic therapy.

Topical delivery of growth factors and metal/metal oxide nanoparticles to infected wounds by polymeric nanoparticles: an overview

INTRODUCTION

Infected chronic wounds particularly diabetic foot ulcers (DFUs) can result from stable colonization of antibiotic-resistant bacteria and fungi at the wound sites. In this context, the rapid healing of infected wounds has been the main goal in recent investigations. This issue can be solved by improving wound-healing phases including hemostasis, inflammatory, proliferative, and remodeling/maturation, and removal of bacteria and fungi. The applications of growth factors (GFs) and metal/metal oxide nanoparticles (MNPs/MONPs) are two choices for these targets. However, the lack of sustainable release of these agents is an important problem for appropriate wound healing.

AREA COVERED

The present review is focused on recent advances in delivery systems composed of growth factor and MNPs/MONPs for rapid wound healing.

EXPERT OPINION

Synthetic and natural polymeric micro- and nanocarriers including polyvinylpyrrolidone (PVP) and chitosan play a vital role in the healing of infected chronic wounds. Using various derivatives of chitosan as pH-responsive polymer with basic and acidic groups can be the best option to prepare controllable and sequential GF release. However, it warrants further extensive research to solve wound-healing problems.

Absorbable Thioether Grafted Hyaluronic Acid Nanofibrous Hydrogel for Synergistic Modulation of Inflammation Microenvironment to Accelerate Chronic Diabetic Wound Healing

Current standard of care dressings are unsatisfactorily inefficacious for the treatment of chronic wounds. Chronic inflammation is the primary cause of the long-term incurable nature of chronic wounds. Herein, an absorbable nanofibrous hydrogel is developed for synergistic modulation of the inflammation microenvironment to accelerate chronic diabetic wound healing. The electrospun thioether grafted hyaluronic acid nanofibers (FHHA-S/Fe) are able to form a nanofibrous hydrogel in situ on the wound bed. This hydrogel degrades and is absorbed gradually within 3 days. The grafted thioethers on HHA can scavenge the reactive oxygen species quickly in the early inflammation phase to relieve the inflammation reactions. Additionally, the HHA itself is able to promote the transformation of the gathered M1 macrophages to the M2 phenotype, thus synergistically accelerating the wound healing phase transition from inflammation to proliferation and remodeling. On the chronic diabetic wound model, the average remaining wound area after FHHA-S/Fe treatment is much smaller than both that of FHHA/Fe without grafted thioethers and the control group, especially in the early wound healing stage. Therefore, this facile dressing strategy with intrinsic dual modulation mechanisms of the wound inflammation microenvironment may act as an effective and safe treatment strategy for chronic wound management.

The biomedical potential of cellulose acetate/polyurethane nanofibrous mats containing reduced graphene oxide/silver nanocomposites and curcumin: Antimicrobial performance and cutaneous wound healing

In this study, nanofibrous scaffolds were prepared from polyurethane and cellulose acetate using electrospinning. Reduced graphene oxide/silver nanocomposites, rGO/Ag, were also used into the mats due to the strong antibacterial activity of rGO/Ag nanocomposites. In order to prevent the agglomeration of silver nanoparticles, AgNPs, the nanoparticles were decorated onto the reduced graphene oxide (rGO) sheets. Initially, Graphene oxide, briefly GO, was synthesized by the improved Hummer method. Then, nanocomposites of reduced graphene oxide were decorated with Ag and were fabricated via a green and facile hydrothermal method. Thereafter, the scaffold containing rGO/Ag nanocomposites, curcumin or both of them were prepared using the electrospinning method. The obtained scaffolds were characterized by scanning electron microscopy (SEM), contact angle, tensile analysis, porosity, and water vapor transmission rate (WVTR). 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay, MTT, confirmed the biocompatibility of the composite nanofibers. The scaffolds were able to hinder both of the Gram-negative and Gram-positive bacteria through direct contact with them. In vivo histopathological studies indicated that the scaffold incorporated rGO/Ag nanocomposites and curcumin has the most effect on wound healing and can promote the healing rate of artificial wounds, which indicates the good biomedical potential of nanomaterial in wound healing.

The photobiomodulation (658, 830 and 904nm) on wound healing in histomorphometric analysis

Abstract Introduction: Photobiomodulation (PBM) assists in the processes of angiogenesis and cellular mitosis after skin lesion, contributing to tissue repair. Objective: to investigate the effects of photobiomodulation (during the proliferative phase) of 658 nm, 830 nm and 904 nm in the repair of skin lesions in an animal model. Method: 658 nm (G658), 830 nm (G830), 904 nm (G904) PBM, and control group (CG) integrated the research. We submitted the animals to an excisional wound and treatment at different wavelengths for 14 days. On the seventh and 14-1485004059th postoperative days, we calculated the area and percentage of lesion contraction. The animals were sacrificed on the 14-1485004056th postoperative day and cutaneous section of the injured region was collected for histomorphometric evaluation of the cellularity, neovascularization, thickness of the epidermis and volume density of collagen fibers colored with H&E and Picross Sirius respectively. For the statistical analysis, we applied the ANOVA test. Results: the G658 presented higher cellularity than GC (p = 0.03). The animals in the G658 group showed a significant increase in the neovascularization in relation to the CG (p = 0.01). Type III collagen significantly increased in G904 compared to G830 (p < 0.0001) and CG (p < 0.0001). The G658 had a significant increase in type III collagen fibers compared to G830 (p < 0.0001) and GC (p < 0.0001). We found no significant difference in the thickness of the epidermis, wound area, and in the percentage wound of contraction between the analyzed groups. Conclusion: PBM was effective to stimulate the tissue repair process, with better results for the 658 nm wavelength.

A review on biological activities of Schiff base, hydrazone, and oxime derivatives of curcumin

Schiff base, hydrazone, and oxime derivatives of curcumin showed enhanced biological activities.

Stereological and gene expression examinations on the combined effects of photobiomodulation and curcumin on wound healing in type one diabetic rats

We examined the effects of photobiomodulation (PBM) independently and combined with curcumin on stereological parameters and basic fibroblast growth factor (bFGF), hypoxia-inducible factor-1α (HIF-1α), and stromal cell-derived factor-1α (SDF-1α) gene expressions in an excisional wound model of rats with type one diabetes mellitus (T1DM). T1DM was induced by an injection of streptozotocin (STZ) in each of the 90 male Wistar rats. One round excision was generated in the skin on the back of each of the 108 rats. The rats were divided into six groups (n = 18 per group): control (diabetic), untreated group; vehicle (diabetic) group, which received sesame oil; PBM (diabetic) group; curcumin (diabetic) group; PBM + curcumin (diabetic) group; and a healthy control group. On days 4, 7, and 15, we conducted both stereological and quantitative real-time PCR (qRT-PCR) analyses. The PBM and PBM + curcumin groups had significantly better inflammatory response modulation in terms of macrophages (P < .01), neutrophils (P < .001), and increased fibroblast values compared with the other groups at day 4 (P < .001), day 7 (P < .01), and day 15 (P < .001). PBM treatment resulted in increased bFGF gene expression on days 4 (P < .001) and 7 (P < .001), and SDF-1α gene expression on day 4 (P < .001). The curcumin group had increased bFGF (P < .001) expression on day 4. Both the PBM and PBM + curcumin groups significantly increased wound healing by modulation of the inflammatory response, and increased fibroblast values and angiogenesis. The PBM group increased bFGF and SDF-1α according to stereological and gene expression analyses compared with the other groups. The PBM and PBM + curcumin groups significantly increased the skin injury repair process to more rapidly reach the proliferation phase of the wound healing in T1DM rats.

An improvement in acute wound healing in mice by the combined application of photobiomodulation and curcumin-loaded iron particles

Here, we examined the combined effect of pulse wave photobiomodulation (PBM) with curcumin-loaded superparamagnetic iron oxide (Fe₃O₄) nanoparticles (curcumin), in an experimental mouse model of acute skin wound. Thirty male adult mice were randomly allocated into 5 groups. Group 1 was served as the control group. Group 2 was a placebo and received distilled water, as a carrier of curcumin. Group 3 received laser (890 nm, 80 Hz, 0.2 J/cm²). Group 4 received curcumin by taking four injections around the wound. Group 5 received laser + curcumin. One full-thickness excisional round wound was made on the back of all the mice. On days 0, 4, 7, and 14, bacterial flora, wound surface area, and tensile strength were examined and microbiological examinations were performed. In case of wound closure, the two-way ANOVA shows that wound surface area of entire groups decreased progressively. However, the decrease in laser + curcumin and laser groups, and especially data from laser + curcumin group were statistically more significant, in comparison with the other groups (F statistics = 2.28, sig = 0.019). In terms of microbiology, the two-way ANOVA showed that laser, and laser + curcumin groups have statistically a lower bacterial count than the curcumin, control, and carrier groups (F statistics = 35, sig = 0 = 000). Finally, the one-way ANOVA showed that laser + curcumin, curcumin, and curcumin significantly increased wound strength, compared to the control and carrier groups. Furthermore, laser + curcumin significantly increased wound strength, compared to the control, laser, and curcumin groups (LSD test, p = 0.003, p = 0.002, and p = 0.005, respectively). In conclusion, curcumin nanoparticles, pulse wave laser, and pulse wave laser + curcumin nanoparticles accelerate wound healing, through a significant increase in wound closure rate, as well as wound strength, and a significant decrease in Staphylococcus aureus counts. Furthermore, the statistical analysis of our data suggests that the combined treatment of pulse wave laser + curcumin nanoparticles enhances the wound closure rate, and wound strength, compared to the laser and curcumin nanoparticles alone.

Neuroprotective Role of Phytochemicals

Neurodegenerative diseases are normally distinguished as disorders with loss of neurons. Various compounds are being tested to treat neurodegenerative diseases (NDs) but they possess solitary symptomatic advantages with numerous side effects. Accumulative studies have been conducted to validate the benefit of phytochemicals to treat neurodegenerative diseases including Alzheimer's disease (AD) and Parkinson's disease (PD). In this present review we explored the potential efficacy of phytochemicals such as epigallocatechin-3-galate, berberin, curcumin, resveratrol, quercetin and limonoids against the most common NDs, including Alzheimer's disease (AD) and Parkinson's disease (PD). The beneficial potentials of these phytochemicals have been demonstrated by evidence-based but more extensive investigation needs to be conducted for reducing the progression of AD and PD.

Combined Effect of Low-Level Laser Treatment and Levothyroxine on Wound Healing in Rats With Hypothyroidism

Introduction: Hypothyroidism delays wound healing by reducing the synthesis of keratinocytes, fibroblast cells, and collagen. Methods for enhancement of wound healing include laser therapy and hormone therapy. The current study evaluated the combined effect of laser and levothyroxine therapy to cure wounds in male rats with hypothyroidism. Methods: Sixty male Wistar rats were randomly divided into 5 groups: (1) healthy controls; (2) controls with hypothyroidism; (3) hypothyroidism + laser treatment; (4) hypothyroidism + levothyroxine treatment; (5) hypothyroidism + laser + levothyroxine treatment. Hypothyroidism was induced by dissolving 4 mg of methimazole in 100 mL of drinking water daily for 28 days. After hypothyroidism had been confirmed, a longitudinal incisional wound was created on the dorsal rib cages of the rats. The wounds that received laser treatment were divided into 12 sections and treated at 810 nm wavelength and 0.2 J/cm2 of energy density for 200 seconds. Levothyroxine was administrated in doses of 20 µg/kg/d i.p. All groups were divided into 3 subgroups for testing on days 4, 7 and 14. Samples were collected in all the subgroups. Results: The results showed that hypothyroidism reduced fibrous tissue volume, fibroblasts, and basal cell numbers. The combined effect of laser and levothyroxine improved all parameters. Conclusion: Combined laser and levothyroxine treatment showed the best effect on wound healing and accelerated the closure of the wounds.

Dual antibacterial behavior of a curcumin–upconversion photodynamic nanosystem for efficient eradication of drug-resistant bacteria in a deep joint infection

The curcumin–upconversion photodynamic nanosystem exhibits dual antibacterial behavior for MRSA-induced periprosthetic joint infection under NIR irradiation.