FW. Clinical Evidence of Dermal and Epidermal Restructuring from a Biologically Active Growth Factor Serum for Skin Rejuvenation

Background: Topical skin care products use various technologies to promote skin repair. Growth factors of human, animal, and plant-derived origins have clinically demonstrated the ability to repair skin by promoting collagen, elastin, and glycosaminoglycan (GAG) production to reconstruct and reinforce skin’s extracellular matrix (ECM). Human skin cells respond to instructions from highly specialized proteins or hormones referred to as growth factors. These growth factors initiate cellular communication that instigates cellular replication, production, or proliferation. The production of elastin and collagen dermal connective fibers slows, and, with age, the regenerative rates of GAGs become delayed. These biological issues can be exacerbated by extrinsic factors such as sun exposure, pollutants, and various other factors. Growth factor-based products have become important topical treatment modalities for addressing signs of skin aging such as fine lines, deep wrinkles, dryness, laxity, and textural irregularities. Objective: The aim of a 12-week clinical trial of a growth factor composition was to assess its effectiveness at restoring skin health through dermal and epidermal restructuring of aged skin. Results: Data from expert grading, and from corneometer and cutometer evaluations, as well as 2D and 3D image analysis, reflected significant improvements in facial skin appearance, firmness, elasticity, and hydration. Elements that improved most dramatically in investigators’ assessments included radiance, firmness, tactile elasticity, textural smoothness, overall appearance, and crow’s feet. Ultrasound imaging showed continual increases in dermal and epidermal restructuring throughout the study duration. Subject assessments reflected positive product tolerability and positive perception across a broad range of efficacy attributes through 12 weeks of usage. Conclusion: The results verified the ability of a multi-modal plant and enzymatically derived growth factor-based product to achieve skin rejuvenation improvements by stimulating dermal ECM and fibrous tissue regeneration to reduce fine lines and coarse wrinkles, and improve skin firmness and elasticity, while restoring skin to a properly hydrated state. J Drugs Dermatol. 2019;18(3):290-295.

Progress in three-dimensional printing with growth factors

Incorporation of growth factors in biomedical constructs can encourage cellular activities necessary for tissue regeneration within an implant system. Three-dimensional printing offers a capacity for spatial dictation and dosage control of incorporated growth factors which promises to minimize complications from the supraphysiologic doses and burst release involved in current growth factor delivery systems. Successful implementation of three-dimensional printing with growth factors requires preservation of the bioactivity of printed growth factors, spatial localization of growth factors within the construct architecture during printing, and controlled release of growth factors after printing. This review describes demonstrated approaches for addressing each of these goals, including direct inclusion of growth factors with the biomaterial during printing, or intermediary encapsulation of growth factors in delivery vehicles such as microparticles or nanoparticles.

Biologically Inspired, Cell-Selective Release of Aptamer-Trapped Growth Factors by Traction Forces

Biomaterial scaffolds that are designed to incorporate dynamic, spatiotemporal information have the potential to interface with cells and tissues to direct behavior. Here, a bioinspired, programmable nanotechnology-based platform is described that harnesses cellular traction forces to activate growth factors, eliminating the need for exogenous triggers (e.g., light), spatially diffuse triggers (e.g., enzymes, pH changes), or passive activation (e.g., hydrolysis). Flexible aptamer technology is used to create modular, synthetic mimics of the Large Latent Complex that restrains transforming growth factor-β1 (TGF-β1). This flexible nanotechnology-based approach is shown here to work with both platelet-derived growth factor-BB (PDGF-BB) and vascular endothelial growth factor (VEGF-165), integrate with glass coverslips, polyacrylamide gels, and collagen scaffolds, enable activation by various cells (e.g., primary human dermal fibroblasts, HMEC-1 endothelial cells), and unlock fundamentally new capabilities such as selective activation of growth factors by differing cell types (e.g., activation by smooth muscle cells but not fibroblasts) within clinically relevant collagen sponges.

Metabolic and neurobehavioral response following intraovarian administration of autologous activated platelet rich plasma: First qualitative data

OBJECTIVES

This work assessed sexual and neurobehavioral parameters after ovarian treatment with autologous PRP.

DESIGN

Questionnaire study.

MATERIAL AND METHODS

Patients receiving ovarian PRP injection (n=80) due to low ovarian reserve and/or at least 1 prior failed IVF cycle were sampled. Pre- and post-treatment levels in self-reported daily energy, sleep quality, skin tone/hair thickness/nail growth, cognitive clarity, menstrual pattern, cervical mucus/vaginal lubrication, libido, sexual activity, ability to achieve orgasm, and overall sexual experience were measured.

RESULTS

Mean±SD age and baseline BMI among patients were 45.5±6yrs and 25±5.1kg/m2, respectively. Average weight loss after ovarian PRP was 1kg (p=0.056). After ovarian PRP, superior nail growth, skin tone, and hair thickness was observed by 46.3% of patients [95%CI=35%,57.8%]; the same ratio experienced increased "clarity of thinking" following the procedure. Irregular or absent menses affected 56.3% of patients at enrollment, and menses returned or cyclicity improved in 24.4% after treatment [95%CI=12.9%,39.5%]. Increased post-treatment vaginal lubrication/cervical mucus production was reported by 51.3% of women [95%CI=39.8%, 62.6%] accompanied by increased libido in 55% [95%CI=43.5%,66.2%]. More frequent sexual activity after ovarian PRP was noted from 46.3% of subjects [95%CI=35%, 57.8%] coinciding with a 45% improvement in overall sexual experience before vs. after ovarian PRP [95%CI=33.9%, 56.5%].

CONCLUSION

This investigation is the first to document responses across neurobehavioral and metabolic parameters after ovarian PRP. Injection of PRP-derived growth factors directly into ovarian tissue seems to enable a local signaling milieu favoring development of hormonally active ovarian elements, thus "re-potentiating" low or absent reserve.

MRGPR-mediated activation of local mast cells clears cutaneous bacterial infection and protects against reinfection

Mast cells (MCs) are strategically distributed at barrier sites and prestore various immunocyte-recruiting cytokines, making them ideal targets for selective activation to treat peripheral infections. Here, we report that topical treatment with mastoparan, a peptide MC activator (MCA), enhances clearance of Staphylococcus aureus from infected mouse skins and accelerates healing of dermonecrotic lesions. Mastoparan functions by activating connective tissue MCs (CTMCs) via the MRGPRX2 (Mas-related G protein-coupled receptor member X2) receptor. Peripheral CTMC activation, in turn, enhances recruitment of bacteria-clearing neutrophils and wound-healing CD301b⁺ dendritic cells. Consistent with MCs playing a master coordinating role, MC activation also augmented migration of various antigen-presenting dendritic cells to draining lymph nodes, leading to stronger protection against a second infection challenge. MCAs therefore orchestrate both the innate and adaptive immune arms, which could potentially be applied to combat peripheral infections by a broad range of pathogens.

Differential profile of protein expression on human keratocytes treated with autologous serum and plasma rich in growth factors (PRGF)

Purpose

The main objective of this study is to compare the protein expression of human keratocytes treated with Plasma rich in growth factors (PRGF) or autologous serum (AS) and previously induced to myofibroblast by TGF-β1 treatment.

Methods

Blood from healthy donor was collected and processed to obtain AS and PRGF eye drops. Blood derivates were aliquoted and stored at -80°C until use. Keratocyte cells were pretreated for 60 minutes with 2.5 ng/ml TGF-β1. After that, cells were treated with PRGF, AS or with TGF-β1 (control). To characterize the proteins deregulated after PRGF and AS treatment, a proteomic approach that combines 1D-SDS–PAGE approach followed by LC–MS/MS was carried out.

Results

Results show a catalogue of key proteins in close contact with a myofibroblastic differentiated phenotype in AS treated-cells, whereas PRGF-treated cells show attenuation on this phenotype. The number of proteins downregulated after PRGF treatment or upregulated in AS-treated cells suggest a close relationship between AS-treated cells and cytoskeletal functions. On the other hand, proteins upregulated after PRGF-treatment or downregulated in AS-treated cells reveal a greater association with processes such as protein synthesis, proliferation and cellular motility.

Conclusion

This proteomic analysis helps to understand the molecular events underlying AS and PRGF-driven tissue regeneration processes, providing new evidence that comes along with the modulation of TGF-β1 activity and the reversion of the myofibroblastic phenotype by PRGF.

Identification of genes which regulate stroma-dependent in vitro hematopoiesis

Cultured splenic stroma has been shown to support in vitro hematopoiesis in overlaid bone marrow and spleen progenitors. These co-cultures support longterm production of a novel dendritic-like cell type along with transient production of myeloid cells. They also maintain a progenitor cell population. The splenic stromal lines 5G3 and 3B5 have been identified as a supporter and a non-supporter of hematopoiesis. Based on their gene expression profile, both 5G3 and 3B5 express genes related to hematopoiesis, while 5G3 cells express several unique genes, and show upregulation of some genes over 3B5. Based on gene expression studies, specific inhibitors were tested for capacity to inhibit hematopoiesis in co-cultures. Addition of specific antibodies and small molecule inhibitors identified VCAM1, CXCL12, CSF1 and SPP1 as potential regulators of hematopoiesis, although both are expressed by 5G3 and 3B5. Through inhibition of function, SVEP1 and ALDH1 are also shown here to be deterministic of 5G3 hematopoietic support capacity, since these are uniquely expressed by 5G3 and not 3B5. The achievement of inhibition is notable given the dynamic, longterm nature of co-cultures which involve only small numbers of cells. The alternate plan, to add recombinant soluble factors produced by 5G3 back into 3B5 co-cultures in order to recover in vitro hematopoiesis, proved ineffective. Out of 6 different factors added to 3B5, only IGF2 showed any effect on cell production. The identification of differentially expressed or upregulated genes in 5G3 has provided an insight into potential pathways involved in in vitro hematopoiesis leading to production of dendritic-like cells.

Magnetic field and nano-scaffolds with stem cells to enhance bone regeneration

Novel strategies utilizing magnetic nanoparticles (MNPs) and magnetic fields are being developed to enhance bone tissue engineering efficacy. This article first reviewed cutting-edge research on the osteogenic enhancements via magnetic fields and MNPs. Then the current developments in magnetic strategies to improve the cells, scaffolds and growth factor deliveries were described. The magnetic-cell strategies included cell labeling, targeting, patterning, and gene modifications. MNPs were incorporated to fabricate magnetic composite scaffolds, as well as to construct delivery systems for growth factors, drugs and gene transfections. The novel methods using magnetic nanoparticles and scaffolds with magnetic fields and stem cells increased the osteogenic differentiation, angiogenesis and bone regeneration by 2-3 folds over those of the controls. The mechanisms of magnetic nanoparticles and scaffolds with magnetic fields and stem cells to enhance bone regeneration were identified as involving the activation of signaling pathways including MAPK, integrin, BMP and NF-κB. Potential clinical applications of magnetic nanoparticles and scaffolds with magnetic fields and stem cells include dental, craniofacial and orthopedic treatments with substantially increased bone repair and regeneration efficacy.

Platelet-targeted dual pathway antithrombotic inhibits thrombosis with preserved hemostasis

Despite advances in antithrombotic therapy, the risk of recurrent coronary/cerebrovascular ischemia or venous thromboembolism remains high. Dual pathway antithrombotic blockade, using both antiplatelet and anticoagulant therapy, offers the promise of improved thrombotic protection; however, widespread adoption remains tempered by substantial risk of major bleeding. Here, we report a dual pathway therapeutic capable of site-specific targeting to activated platelets and therapeutic enrichment at the site of thrombus growth to allow reduced dosing without compromised antithrombotic efficacy. We engineered a recombinant fusion protein, SCE5-TAP, which consists of a single-chain antibody (SCE5) that targets and blocks the activated GPIIb/IIIa complex, and tick anticoagulant peptide (TAP), a potent direct inhibitor of activated factor X (FXa). SCE5-TAP demonstrated selective platelet targeting and inhibition of thrombosis in murine models of both carotid artery and inferior vena cava thrombosis, without a significant impact on hemostasis. Selective targeting to activated platelets provides an attractive strategy to achieve high antithrombotic efficacy with reduced risk of bleeding complications.

Myeloid Growth Factors, Version 2.2017, NCCN Clinical Practice Guidelines in Oncology

Myeloid growth factors (MGFs) are given as supportive care to patients receiving myelosuppressive chemotherapy to reduce the incidence of neutropenia. This selection from the NCCN Guidelines for MGFs focuses on the evaluation of regimen- and patient-specific risk factors for the development of febrile neutropenia (FN), the prophylactic use of MGFs for the prevention of chemotherapy-induced FN, and assessing the risks and benefits of MGF use in clinical practice.

Hepatic and cardiac beneficial effects of a long-acting Fc-apelin fusion protein in diet-induced obese mice

BACKGROUND

Apelin is a peptide ligand of the G-protein-coupled receptor APJ and exhibits anti-diabetes and anti-heart failure activities. However, short serum half-life of the apelin peptide limits its potential clinical applications. This study aimed to develop a long-acting apelin analog.

METHODS

To extend apelin's in vivo half-life, we made a recombinant protein by fusing the IgG Fc fragment to apelin-13 (Fc-apelin-13), conducted pharmacokinetics studies in mice, and determined in vitro biological activities in suppressing cyclic adenosine monophosphate and activating extracellular signal-regulated kinase signalling by reporter assays. We investigated the effects of Fc-apelin-13 on food intake, body weight, fasting blood glucose and insulin levels, glucose tolerance test, hepatic steatosis, and cardiac function and fibrosis by subcutaneous administration of Fc-apelin-13 in diet-induced obese mice for 4 weeks.

RESULTS

The estimated half-life of Fc-apelin-13 in blood was approximately 33 hours. Reporter assays showed that Fc-apelin-13 was active in suppressing cyclic adenosine monophosphate response element and activating serum response element activities. Four weeks of Fc-apelin-13 treatment in obese mice did not affect food intake and body weight, but resulted in a significant improvement of glucose tolerance, and a decrease in hepatic steatosis and fibrosis, as well as in serum alanine transaminase levels. Moreover, cardiac stroke volume and output were increased and cardiac fibrosis was decreased in the treated mice.

CONCLUSIONS

Fc-apelin-13 fusion protein has an extended in vivo half-life and exerts multiple benefits on obese mice with respect to the improvement of glucose disposal, amelioration of liver steatosis and heart fibrosis, and increase of cardiac output. Hence, Fc-apelin-13 is potentially a therapeutic for obesity-associated disease conditions.

Injectable shear-thinning hydrogels for delivering osteogenic and angiogenic cells and growth factors

Bone nonunion may occur when the fracture is unstable, or blood supply is impeded. To provide an effective treatment for the healing of nonunion defects, we introduce an injectable osteogenic hydrogel that can deliver cells and vasculogenic growth factors. We used a silicate-based shear-thinning hydrogel (STH) to engineer an injectable scaffold and incorporated polycaprolactone (PCL) nanoparticles that entrap and release vasculogenic growth factors in a controlled manner. By adjusting the solid composition of gelatin and silicate nanoplatelets in the STH, we defined optimal conditions that enable injection of STHs, which can deliver cells and growth factors. Different types of STHs could be simultaneously injected into 3D constructs through a single extrusion head composed of multiple syringes and needles, while maintaining their engineered structure in a continuous manner. The injected STHs were also capable of filling any irregularly shaped defects in bone. Osteogenic cells and endothelial cells were encapsulated in STHs with and without vasculogenic growth factors, respectively, and when co-cultured, their growth and differentiation were significantly enhanced compared to cells grown in monoculture. This study introduces an initial step of developing a new platform of shape-tunable materials with controlled release of angiogenic growth factors by utilizing PCL nanoparticles.

Apelin in the hypothalamic paraventricular nucleus improves cardiac function in surgical trauma rats

Apelin is a novel endogenous active peptide. The aim of this study is to investigate whether apelin in the paraventricular nucleus (PVN) can improve the cardiac function in rats subjected to thoracic surgery trauma, and whether it is involved in the protective effect of electro-acupuncture (EA). Sprague-Dawley rats were randomly divided into non-stressed group (control), thoracic surgical trauma stressed group (trauma) and bilateral Neiguan EA applied on thoracic surgical trauma stressed group (trauma + EA-PC 6). The mRNA expressions of apelin receptor (APJR) and apelin in the PVN were detected by real time-PCR. The exogenous apelin-13 (6 mmol/L, 0.1 μL) was microinjected into the rat PVN in the thoracic trauma group, and the effects of apelin-13 on the blood pressure (BP), heart rate (HR) and the discharge of rostral ventrolateral medulla (RVLM) neurons were observed through the simultaneous recording technology by polygraph. The results showed that the APJR mRNA expression was significantly decreased in the rats of trauma group as compared with that in the control group (P < 0.05), and a decline trend of apelin mRNA expression was also observed. EA application at bilateral Neiguan acupoints partially recovered the decline of APJR and apelin mRNA expression by the treatment of thoracic trauma. Both mean arterial pressure and HR in the thoracic surgical trauma group were significantly increased by the microinjection of exogenous apelin-13 into the PVN (P < 0.05), and the single-unit discharge rate of RVLM neurons also had an increasing trend. These results suggest that apelin in the PVN can improve the cardiac function of thoracic surgical trauma rats, and may be involved in the protective effects of EA.

Platelet rich plasma and growth factors cocktails for diabetic foot ulcers treatment: State of art developments and future prospects

Current advances in diabetic foot ulcers (DFU) treatment are discussed. Normal and pathological wound healing process are observed and the role of growth factors (GFs) is elucidated. Current techniques involving GFs and platelet rich plasma (PRP) are compared. Up-to-date research suggests that treatment with single growth factor (GF) could be insufficient and not encompassing all pathological changes in DFU bed. Efficiency of PRP is rather controversial and lacks evidence. Thus the use of cocktail of particular GFs is suggested. Pro et contra of each approach are discussed.

Apelin-13 ameliorates cognitive impairments in 6-hydroxydopamine-induced substantia nigra lesion in rats

Although Parkinson's disease (PD) is well known with its motor deficits, the patients often suffer from cognitive dysfunction. Apelin, as the endogenous ligand of the APJ receptor, is found in several brain regions such as substantia nigra and mesolimbic pathway. However, the role of apelin in cognition and cognitive disorders has not been fully clarified. In this study the effects of apelin-13 were investigated on cognitive disorders in rat Parkinsonism experimental model. 6-hydroxydopamine (6-OHDA) was administrated into the substantia nigra. Apelin-13 (1, 2 and 3μg/rat) was administered into the substantia nigra one week after the 6-OHDA injection. Morris water maze (MWM), object location and novel object recognition tests were performed one month after the apelin injection. 6-OHDA-treated animals showed a significant impairment in cognitive functions which was revealed by the increased in the escape latency and traveled distance in MWM test and decreased in the exploration index in novel object recognition and object location tasks. Apelin-13 (3μg/rat) significantly attenuates the mentioned cognitive impairments in 6-OHDA-treated animals. In conclusion, the data support the pro-cognitive property of apelin-13 in 6-OHDA-induced cognitive deficit and provided a new pharmacological aspect of the neuropeptide apelin.

A Prominent Role of Interleukin-18 in Acetaminophen-Induced Liver Injury Advocates Its Blockage for Therapy of Hepatic Necroinflammation

Acetaminophen [paracetamol, N-acetyl-p-aminophenol (APAP)]-induced acute liver injury (ALI) not only remains a persistent clinical challenge but likewise stands out as well-characterized paradigmatic model of drug-induced liver damage. APAP intoxication associates with robust hepatic necroinflammation the role of which remains elusive with pathogenic but also pro-regenerative/-resolving functions being ascribed to leukocyte activation. Here, we shine a light on and put forward a unique role of the interleukin (IL)-1 family member IL-18 in experimental APAP-induced ALI. Indeed, amelioration of disease as previously observed in IL-18-deficient mice was further substantiated herein by application of the IL-18 opponent IL-18-binding protein (IL-18BPd:Fc) to wild-type mice. Data altogether emphasize crucial pathological action of this cytokine in APAP toxicity. Adding recombinant IL-22 to IL-18BPd:Fc further enhanced protection from liver injury. In contrast to IL-18, the role of prototypic pro-inflammatory IL-1 and tumor necrosis factor-α is controversially discussed with lack of effects or even protective action being repeatedly reported. A prominent detrimental function for IL-18 in APAP-induced ALI as proposed herein should relate to its pivotal role for hepatic expression of interferon-γ and Fas ligand, both of which aggravate APAP toxicity. As IL-18 serum levels increase in patients after APAP overdosing, targeting IL-18 may evolve as novel therapeutic option in those hard-to-treat patients where standard therapy with N-acetylcysteine is unsuccessful. Being a paradigmatic experimental model of ALI, current knowledge on ill-fated properties of IL-18 in APAP intoxication likewise emphasizes the potential of this cytokine to serve as therapeutic target in other entities of inflammatory liver diseases.

Apelin-13 analogues show potent in vitro and in vivo insulinotropic and glucose lowering actions

Nine structurally modified apelin-13 analogues were assessed for their in vitro and acute in vivo antidiabetic potential. Stability was assessed in mouse plasma and insulinotropic efficacy tested in cultured pancreatic BRIN-BD11 cells and isolated mouse pancreatic islets. Intracellular Ca²⁺ and cAMP production in BRIN-BD11 cells was determined, as was glucose uptake in 3T3-L1 adipocytes. Acute antihyperglycemic effects of apelin analogues were assessed following i.p. glucose tolerance tests (ipGGT, 18 mmol/kg) in normal and diet-induced-obese (DIO) mice and on food intake in normal mice. Apelin analogues all showed enhanced in vitro stability (up to 5.8-fold, t½ = 12.8 h) in mouse plasma compared to native apelin-13 (t½ = 2.1 h). Compared to glucose controls, stable analogues exhibited enhanced insulinotropic responses from BRIN-BD11 cells (up to 4.7-fold, p < 0.001) and isolated mouse islets (up to 5.3-fold) for 10^-7 M apelin-13 amide (versus 7.6-fold for 10^-7 M GLP-1). Activation of APJ receptors on BRIN-BD11 cells increased intracellular Ca²⁺ (up to 3.0-fold, p < 0.001) and cAMP (up to 1.7-fold, p < 0.01). Acute ipGTT showed improved insulinotropic and glucose disposal responses in normal and DIO mice (p < 0.05 and p < 0.01, respectively). Apelin-13 amide and (pGlu)apelin-13 amide were the most effective analogues exhibiting acute, dose-dependent and persistent biological actions. Both analogues stimulated insulin-independent glucose uptake by differentiated adipocytes (2.9-3.3-fold, p < 0.05) and inhibited food intake (26-33%, p < 0.001), up to 180 min in mice, versus saline. In contrast, (Ala¹³)apelin-13 and (Val¹³)apelin-13 inhibited insulin secretion, suppressed beta-cell signal transduction and stimulated food intake in mice. Thus, stable analogues of apelin-13 have potential for diabetes/obesity therapy.

Apelin administration improves insulin sensitivity in overweight men during hyperinsulinaemic-euglycaemic clamp

AIMS

Apelin is a recently identified adipokine known to improve glucose tolerance and insulin sensitivity in murine models. This study was dedicated to the proof of concept that apelin administration also enhances insulin sensitivity in humans.

MATERIALS AND METHODS

Healthy overweight men were enrolled in this randomized, double-blind, placebo-controlled, cross-over study that successively considered the efficacy and the tolerance of 2 doses of (pyr1)-Apelin-13. A first group of subjects received 9 nmol/kg (n = 8) of (pyr1)-Apelin-13 and, after examination of safety data, a second group received 30 nmol/kg (n = 8). Each volunteer underwent 2 hyperinsulinaemic-euglycaemic clamps where the basal level of glucose infusion rate (GIR) was measured from the 90th to the 120th minute (level 1). Continuous intravenous administration of apelin or placebo was ongoing for 2 hours and GIR was finally evaluated from the 210th to the 240th minute (level 2). Primary evaluation endpoint was the difference in GIR between level 2 and level 1 (ΔGIR).

RESULTS

A slight increase in ΔGIR was observed with the low apelin dose (0.65 ± 0.71 mg/kg/min, P = .055) whereas the highest dose significantly improved insulin sensitivity (0.82 ± 0.71 mg/kg/min, P = .033). Cardiovascular monitoring and safety reports did not reveal any side effect of apelin administration.

CONCLUSION

As the first demonstration of the insulin-sensitizing action of apelin in humans, alongside numerous studies in rodents, this trial confirms that the apelin/APJ pathway should be considered as a new target to design alternative therapeutic strategies to control insulin resistance in type 2 diabetic patients.

Timed Delivery of Therapy Enhances Functional Muscle Regeneration

Cell transplantation is a promising therapeutic strategy for the treatment of traumatic muscle injury in humans. Previous investigations have typically focused on the identification of potent cell and growth factor treatments and optimization of spatial control over delivery. However, the optimal time point for cell transplantation remains unclear. Here, this study reports how myoblast and morphogen delivery timed to coincide with specific phases of the inflammatory response affects donor cell engraftment and the functional repair of severely injured muscle. Delivery of a biomaterial-based therapy timed with the peak of injury-induced inflammation leads to potent early and long-term regenerative benefits. Diminished inflammation and fibrosis, enhanced angiogenesis, and increased cell engraftment are seen during the acute stage following optimally timed treatment. Over the long term, treatment during peak inflammation leads to enhanced functional regeneration, as indicated by reduced chronic inflammation and fibrosis along with increased tissue perfusion and muscle contractile force. Treatments initiated immediately after injury or after inflammation had largely resolved provided more limited benefits. These results demonstrate the importance of appropriately timing the delivery of biologic therapy in the context of muscle regeneration. Biomaterial-based timed delivery can likely be applied to other tissues and is of potential wide utility in regenerative medicine.

Temporally controlled growth factor delivery from a self-assembling peptide hydrogel and electrospun nanofibre composite scaffold

Tissue-specific self-assembling peptide (SAP) hydrogels designed based on biologically relevant peptide sequences have great potential in regenerative medicine. These materials spontaneously form 3D networks of physically assembled nanofibres utilising non-covalent interactions. The nanofibrous structure of SAPs is often compared to that of electrospun scaffolds. These electrospun nanofibers are produced as sheets that can be engineered from a variety of polymers that can be chemically modified to incorporate many molecules including drugs and growth factors. However, their macroscale morphology limits them to wrapping and bandaging applications. Here, for the first time, we combine the benefits of these systems to describe a two-component composite scaffold from these biomaterials, with the design goal of providing a hydrogel scaffold that presents 3D structures, and also has temporal control over drug delivery. Short fibres, cut from electrospun scaffolds, were mixed with our tissue-specific SAP hydrogel to provide a range of nanofibre sizes found in the extracellular matrix (10-300 nm in diameter). The composite material maintained the shear-thinning and void-filling properties of SAP hydrogels that have previously been shown to be effective for minimally invasive material injection, cell delivery and subsequent in vivo integration. Both scaffold components were separately loaded with growth factors, important signaling molecules in tissue regeneration whose rapid degradation limits their clinical efficacy. The two biomaterials provided sequential growth factor delivery profiles: the SAP hydrogel provided a burst release, with the release rate decreasing over 12 hours, while the electrospun nanofibres provided a more constant, sustained delivery. Importantly, this second release commenced 6 days later. The design rules established here to provide temporally distinct release profiles can enable researchers to target specific stages in regeneration, such as the acute immune response versus sustained protection and survival of cells following injury. In summary, this novel composite material combines the physical advantages of SAP hydrogels and electrospun nanofibres, while additionally providing a superior vehicle for the stabilisation and controlled delivery of growth factors necessary for optimal tissue repair.

Progranulin gene delivery reduces plaque burden and synaptic atrophy in a mouse model of Alzheimer's disease

Progranulin (PGRN) is a multifunctional protein that is widely expressed throughout the brain, where it has been shown to act as a critical regulator of CNS inflammation and also functions as an autocrine neuronal growth factor, important for long-term neuronal survival. PGRN has been shown to activate cell signaling pathways regulating excitoxicity, oxidative stress, and synaptogenesis, as well as amyloidogenesis. Together, these critical roles in the CNS suggest that PGRN has the potential to be an important therapeutic target for the treatment of various neurodegenerative disorders, particularly Alzheimer’s disease (AD). AD is the leading cause of dementia and is marked by the appearance of extracellular plaques consisting of aggregates of amyloid-β (Aβ), as well as neuroinflammation, oxidative stress, neuronal loss and synaptic atrophy. The ability of PGRN to target multiple key features of AD pathophysiology suggests that enhancing its expression may benefit this disease. Here, we describe the application of PGRN gene transfer using in vivo delivery of lentiviral expression vectors in a transgenic mouse model of AD. Viral vector delivery of the PGRN gene effectively enhanced PGRN expression in the hippocampus of Tg2576 mice. This elevated PGRN expression significantly reduced amyloid plaque burden in these mice, accompanied by reductions in markers of inflammation and synaptic atrophy. The overexpression of PGRN was also found to increase activity of neprilysin, a key amyloid beta degrading enzyme. PGRN regulation of neprilysin activity could play a major role in the observed alterations in plaque burden. Thus, PGRN may be an effective therapeutic target for the treatment of AD.

Advanced Growth Factor Delivery Systems in Wound Management and Skin Regeneration

Growth factors are endogenous signaling molecules that regulate cellular responses required for wound healing processes such as migration, proliferation, and differentiation. However, exogenous application of growth factors has limited effectiveness in clinical settings due to their low in vivo stability, restricted absorption through skin around wound lesions, elimination by exudation prior to reaching the wound area, and other unwanted side effects. Sophisticated systems to control the spatio-temporal delivery of growth factors are required for the effective and safe use of growth factors as regenerative treatments in clinical practice, such as biomaterial-based drug delivery systems (DDSs). The current review describes the roles of growth factors in wound healing, their clinical applications for the treatment of chronic wounds, and advances in growth factor-loaded DDSs for enhanced wound healing, focusing on micro- and nano-particulate systems, scaffolds, hydrogels, and other miscellaneous systems.

Use of Hormones, Tissue Factors and Bioengineering in the Management of Hypospadias

Hypospadiology is a rapidly evolving field. Progress in the understanding of how hormonal therapy affects the growth of the phallus has allowed surgeons to optimize the tissues for surgery. But conflicting data from a number of studies and a lack of consensus on drugs, their dosing, mode of delivery and timing of use means that the creation of protocols is unlikely to happen in the near future. Nonetheless, there is a hope and the standardization of scientific reporting will make it easier to compare data at the global level. There are reports of the increasing incidence of hypospadias and the etiology is thought to be multifactorial. Although complex interactions between genetic polymorphisms and the environment make it difficult to identify the exact factors responsible for hypospadias, the advent of massively parallel gene sequencing, large scale epigenetic screens and CRISPR technology will definitely ease the process. The knowledge of culprit genes will not only broaden our understanding of embryology and growth but will also enable us to predict and/or modify tissue healing. Advances in tissue engineering are also expected to provide a plethora of biomaterials for urethral reconstruction. The development of this field is directly linked with the elucidation of the processes of proliferation and vascularization coupled with the cataloguing of the growth factors involved. One can safely conclude that the exciting new advances in the field will have far reaching consequences on patient care and counselling.

A comparative study to evaluate the efficacy of EGF, FGF-2, and 0.3% (w/v) ofloxacin drops on eardrum regeneration

BACKGROUND

Traumatic tympanic membrane perforations (TMPs) tend to spontaneous healing, however, large TMPs usually fail to healing. Clinical and experimental studies had demonstrated that growth factors accelerated the healing of large TMPs. The aim of this study was to compare the effects of growth factors and 0.3% (w/v) ofloxacin drops n the healing of human large TMPs.

METHODS

A total of 184 human large traumatic TMPs were randomly assigned to receive epidermal growth factor (EGF) treatment, fibroblast growth factor-2 (FGF-2) treatment, 0.3% (w/v) ofloxacin drops treatment, and conservative observation (only).

RESULTS

A total of 180 patients were analyzed in this study at the 6-month follow-up. The closure rates of the perforations in the EGF, FGF-2, 0.3% (w/v) ofloxacin drops, and conservative observation groups were 91.11%, 93.18%, 95.65%, and 82.22%, respectively, the closure rates did not significantly differ among the groups (P = .165). Similarly, pairwise comparisons did not reveal any significant between-group differences (P > .0083). However, the difference of the mean closure time was significant among the 4 groups (P < .001), pairwise comparisons showed that closure time was significantly longer in the observational group than in the other 3 groups (P < .001). Nevertheless, no significant difference in mean closure time was evident between any 2 treated groups (P > .0083). The mean hearing gain after 6 months was 11.49 ± 5.88 dB for the EGF group, 10.89 ± 5.16 dB for the FGF-2 group, 10.54 ± 5.56 dB for the ofloxacin group, and 9.29 ± 5.36 dB for the observation group. Differences in hearing improvement rates among the 4 groups were not statistically significant (P = .283).

CONCLUSION

Epidermal growth factor, FGF-2, and 0.3% (w/v) ofloxacin drops accelerated the closure of large TMPs compared with conservative treatment. Surprisingly, neither the closure rate nor closure time differed significantly among the 3 treated groups. Further experimental studies to demonstrate whether 0.3% (w/v) ofloxacin per se accelerates the healing of TMPs will be interesting in the future.

Topical antimicrobial agents for treating foot ulcers in people with diabetes

BACKGROUND

People with diabetes are at high risk for developing foot ulcers, which often become infected. These wounds, especially when infected, cause substantial morbidity. Wound treatments should aim to alleviate symptoms, promote healing, and avoid adverse outcomes, especially lower extremity amputation. Topical antimicrobial therapy has been used on diabetic foot ulcers, either as a treatment for clinically infected wounds, or to prevent infection in clinically uninfected wounds.

OBJECTIVES

To evaluate the effects of treatment with topical antimicrobial agents on: the resolution of signs and symptoms of infection; the healing of infected diabetic foot ulcers; and preventing infection and improving healing in clinically uninfected diabetic foot ulcers.

SEARCH METHODS

We searched the Cochrane Wounds Specialised Register, CENTRAL, Ovid MEDLINE, Ovid MEDLINE (In-Process & Other Non-Indexed Citations), Ovid Embase, and EBSCO CINAHL Plus in August 2016. We also searched clinical trials registries for ongoing and unpublished studies, and checked reference lists to identify additional studies. We used no restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials conducted in any setting (inpatient or outpatient) that evaluated topical treatment with any type of solid or liquid (e.g., cream, gel, ointment) antimicrobial agent, including antiseptics, antibiotics, and antimicrobial dressings, in people with diabetes mellitus who were diagnosed with an ulcer or open wound of the foot, whether clinically infected or uninfected.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment, and data extraction. Initial disagreements were resolved by discussion, or by including a third review author when necessary.

MAIN RESULTS

We found 22 trials that met our inclusion criteria with a total of over 2310 participants (one study did not report number of participants). The included studies mostly had small numbers of participants (from 4 to 317) and relatively short follow-up periods (4 to 24 weeks). At baseline, six trials included only people with ulcers that were clinically infected; one trial included people with both infected and uninfected ulcers; two trials included people with non-infected ulcers; and the remaining 13 studies did not report infection status.Included studies employed various topical antimicrobial treatments, including antimicrobial dressings (e.g. silver, iodides), super-oxidised aqueous solutions, zinc hyaluronate, silver sulphadiazine, tretinoin, pexiganan cream, and chloramine. We performed the following five comparisons based on the included studies: Antimicrobial dressings compared with non-antimicrobial dressings: Pooled data from five trials with a total of 945 participants suggest (based on the average treatment effect from a random-effects model) that more wounds may heal when treated with an antimicrobial dressing than with a non-antimicrobial dressing: risk ratio (RR) 1.28, 95% confidence interval (CI) 1.12 to 1.45. These results correspond to an additional 119 healing events in the antimicrobial-dressing arm per 1000 participants (95% CI 51 to 191 more). We consider this low-certainty evidence (downgraded twice due to risk of bias). The evidence on adverse events or other outcomes was uncertain (very low-certainty evidence, frequently downgraded due to risk of bias and imprecision). Antimicrobial topical treatments (non dressings) compared with non-antimicrobial topical treatments (non dressings): There were four trials with a total of 132 participants in this comparison that contributed variously to the estimates of outcome data. Evidence was generally of low or very low certainty, and the 95% CIs spanned benefit and harm: proportion of wounds healed RR 2.82 (95% CI 0.56 to 14.23; 112 participants; 3 trials; very low-certainty evidence); achieving resolution of infection RR 1.16 (95% CI 0.54 to 2.51; 40 participants; 1 trial; low-certainty evidence); undergoing surgical resection RR 1.67 (95% CI 0.47 to 5.90; 40 participants; 1 trial; low-certainty evidence); and sustaining an adverse event (no events in either arm; 81 participants; 2 trials; very low-certainty evidence). Comparison of different topical antimicrobial treatments: We included eight studies with a total of 250 participants, but all of the comparisons were different and no data could be appropriately pooled. Reported outcome data were limited and we are uncertain about the relative effects of antimicrobial topical agents for each of our review outcomes for this comparison, that is wound healing, resolution of infection, surgical resection, and adverse events (all very low-certainty evidence). Topical antimicrobials compared with systemic antibiotics : We included four studies with a total of 937 participants. These studies reported no wound-healing data, and the evidence was uncertain for the relative effects on resolution of infection in infected ulcers and surgical resection (very low certainty). On average, there is probably little difference in the risk of adverse events between the compared topical antimicrobial and systemic antibiotics treatments: RR 0.91 (95% CI 0.78 to 1.06; moderate-certainty evidence - downgraded once for inconsistency). Topical antimicrobial agents compared with growth factor: We included one study with 40 participants. The only review-relevant outcome reported was number of ulcers healed, and these data were uncertain (very low-certainty evidence).

AUTHORS' CONCLUSIONS

The randomised controlled trial data on the effectiveness and safety of topical antimicrobial treatments for diabetic foot ulcers is limited by the availability of relatively few, mostly small, and often poorly designed trials. Based on our systematic review and analysis of the literature, we suggest that: 1) use of an antimicrobial dressing instead of a non-antimicrobial dressing may increase the number of diabetic foot ulcers healed over a medium-term follow-up period (low-certainty evidence); and 2) there is probably little difference in the risk of adverse events related to treatment between systemic antibiotics and topical antimicrobial treatments based on the available studies (moderate-certainty evidence). For each of the other outcomes we examined there were either no reported data or the available data left us uncertain as to whether or not there were any differences between the compared treatments. Given the high, and increasing, frequency of diabetic foot wounds, we encourage investigators to undertake properly designed randomised controlled trials in this area to evaluate the effects of topical antimicrobial treatments for both the prevention and the treatment of infection in these wounds and ultimately the effects on wound healing.