A rhPDGF-BB/bovine type I collagen/ß-TCP mixture for the treatment of critically sized non-union tibial defects: An in vivo study in rabbits.

Non-union during healing of bone fractures affects up to ~5% of patients worldwide. Given the success of recombinant human platelet-derived growth factor-B chain homodimer (rhPDGF-BB) in promoting angiogenesis and bone fusion in the hindfoot and ankle, rhPDGF-BB combined with bovine type I collagen/ß-TCP matrix (AIBG) could serve as a viable alternative to autografts in the treatment of non-unions. Defects (~2 mm gaps) were surgically induced in tibiae of skeletally mature New Zealand white rabbits. Animals were allocated to one of four groups-(1) negative control (empty defect, healing for 8 weeks), (2 and 3) acute treatment with AIBG (healing for 4 or 8 weeks), and (4) chronic treatment with AIBG (injection 4 weeks post defect creation and then healing for 8 weeks). Bone formation was analyzed qualitatively and semi-quantitatively through histology. Samples were imaged using dual-energy X-ray absorptiometry and computed tomography for defect visualization and volumetric reconstruction, respectively. Delayed healing or non-healing was observed in the negative control group, whereas defects treated with AIBG in an acute setting yielded bone formation as early as 4 weeks with bone growth appearing discontinuous. At 8 weeks (acute setting), substantial remodeling was observed with higher degrees of bone organization characterized by appositional bone growth. The chronic healing, experimental, group yielded bone formation and remodeling, with no indication of non-union after treatment with AIBG. Furthermore, bone growth in the chronic healing group was accompanied by an increased presence of osteons, osteonal canals, and interstitial lamellae. Qualitatively and semiquantitatively, chronic application of AI facilitated complete bridging of the induced non-union defects, while untreated defects or defects treated acutely with AIBG demonstrated a lack of complete bridging at 8 weeks.

PDGF-D Is Dispensable for the Development and Progression of Murine Alport Syndrome.

Alport syndrome is an inherited kidney disease, which can lead to glomerulosclerosis and fibrosis, as well as end-stage kidney disease in children and adults. Platelet-derived growth factor-D (PDGF-D) mediates glomerulosclerosis and interstitial fibrosis in various models of kidney disease, prompting investigation of its role in a murine model of Alport syndrome. In vitro, PDGF-D induced proliferation and profibrotic activation of conditionally immortalized human parietal epithelial cells. In Col4a3-/- mice, a model of Alport syndrome, PDGF-D mRNA and protein were significantly up-regulated compared with non-diseased wild-type mice. To analyze the therapeutic potential of PDGF-D inhibition, Col4a3-/- mice were treated with a PDGF-D neutralizing antibody. Surprisingly, PDGF-D antibody treatment had no effect on renal function, glomerulosclerosis, fibrosis, or other indices of kidney injury compared with control treatment with unspecific IgG. To characterize the role of PDGF-D in disease development, Col4a3-/- mice with a constitutive genetic deletion of Pdgfd were generated and analyzed. No difference in pathologic features or kidney function was observed in Col4a3-/-Pdgfd-/- mice compared with Col4a3-/-Pdgfd+/+ littermates, confirming the antibody treatment data. Mechanistically, lack of proteolytic PDGF-D activation in Col4a3-/- mice might explain the lack of effects in vivo. In conclusion, despite its established role in kidney fibrosis, PDGF-D, without further activation, does not mediate the development and progression of Alport syndrome in mice.

Current progress in growth factors and extracellular vesicles in tendon healing.

Tendon injury healing is a complex process that involves the participation of a significant number of molecules and cells, including growth factors molecules in a key role. Numerous studies have demonstrated the function of growth factors in tendon healing, and the recent emergence of EV has also provided a new visual field for promoting tendon healing. This review examines the tendon structure, growth, and development, as well as the physiological process of its healing after injury. The review assesses the role of six substances in tendon healing: insulin-like growth factor-I (IGF-I), transforming growth factor ß (TGFß), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), and EV. Different growth factors are active at various stages of healing and exhibit separate physiological activities. IGF-1 is expressed immediately after injury and stimulates the mitosis of various cells while suppressing the response to inflammation. VEGF, which is also active immediately after injury, accelerates local metabolism by promoting vascular network formation and positively impacts the activities of other growth factors. However, VEGF's protracted action could be harmful to tendon healing. PDGF, the earliest discovered cytokine to influence tendon healing, has a powerful cell chemotaxis and promotes cell proliferation, but it can equally accelerate the response to inflammation and relieve local adhesions. Also useful for relieving tendon adhesion is TGF- ß, which is active almost during the entire phase of tendon healing. As a powerful active substance, in addition to its participation in the field of cardiovascular and cerebrovascular vessels, tumour and chronic wounds, TGF- ß reportedly plays a role in promoting cell proliferation, activating growth factors, and inhibiting inflammatory response during tendon healing.

Supramolecular Hydrogel Microspheres of Platelet-Derived Growth Factor Mimetic Peptide Promote Recovery from Spinal Cord Injury.

Neural stem cells (NSCs) are considered to be prospective replacements for neuronal cell loss as a result of spinal cord injury (SCI). However, the survival and neuronal differentiation of NSCs are strongly affected by the unfavorable microenvironment induced by SCI, which critically impairs their therapeutic ability to treat SCI. Herein, a strategy to fabricate PDGF-MP hydrogel (PDGF-MPH) microspheres (PDGF-MPHM) instead of bulk hydrogels is proposed to dramatically enhance the efficiency of platelet-derived growth factor mimetic peptide (PDGF-MP) in activating its receptor. PDGF-MPHM were fabricated by a piezoelectric ceramic-driven thermal electrospray device, had an average size of 9 µm, and also had the ability to activate the PDGFRß of NSCs more effectively than PDGF-MPH. In vitro, PDGF-MPHM exerted strong neuroprotective effects by maintaining the proliferation and inhibiting the apoptosis of NSCs in the presence of myelin extracts. In vivo, PDGF-MPHM inhibited M1 macrophage infiltration and extrinsic or intrinsic cells apoptosis on the seventh day after SCI. Eight weeks after SCI, the T10 SCI treatment results showed that PDGF-MPHM + NSCs significantly promoted the survival of NSCs and neuronal differentiation, reduced lesion size, and considerably improved motor function recovery in SCI rats by stimulating axonal regeneration, synapse formation, and angiogenesis in comparison with the NSCs graft group. Therefore, our findings provide insights into the ability of PDGF-MPHM to be a promising therapeutic agent for SCI repair.

Platelet-derived growth factor AA-modified electrospun fibers promote tendon healing.

Platelet-derived growth factor AA (PDGF-AA) is an important promoter of tissue injury repair and might be a candidate for improving the mechanical properties of repaired tendons. Here, we designed a PDGF-AA-modified poly(lactide-co-glycolide) acid (PLGA) electrospun fibers to promote tendon rehabilitation after injury. In the present study, we grafted PDGF-AA on the surface of PLGA. In structural experiments, we found that the hydrophilicity of PLGA containing PDGF-AA (PLGA-PDGF-AA) increased, but the strength of the material did not change significantly. Moreover, no significant changes in tendon cell proliferation and viability were observed in the PLGA-PDGF-AA treatment compared with the control group. The mouse tendon injury model (n = 9) experiment illustrated that PLGA-PDGF-AA effectively promoted tendon healing, and we confirmed that PLGA-PDGF-AA promoted collagen synthesis and deposition by immunohistochemistry and RT-PCR. Moreover, the mechanical strength of PLGA-PDGF-AA-treated mouse (n = 9) tendon tissue was also higher than that of the PLGA-treated group alone. In conclusion, PLGA-PDGF-AA promoted regeneration after tendon injury and serves as a potential adjuvant material for surgical tendon injury repair.

Platelet derived growth factor and its receptor in intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is a common and highly disabling or fatal neurological disorder in adults. Recent studies have suggested that the platelet derived growth factor (PDGF) signaling pathway plays an important role in the development of ICH. PDGF is involved in vascular remodeling and can be used as a biomarker of cerebral amyloid angiopathy which is one of the major causes of ICH. PDGF and its receptors are involved in the mechanism of the secondary injury after ICH by affecting the integrity of the blood-brain barrier and inflammatory response. PDGF and its receptors may also participate in the mechanism of repair after ICH by promoting angiogenesis. This article reviews the latest research progress on the involvement of PDGF signaling pathway in the pathophysiology of intracerebral hemorrhage, and introduces the relevant antagonists using PDGFR as the therapeutic target, to provide information for the development of therapeutic options for intracerebral hemorrhage.

lncRNA H22954 Inhibits Angiogenesis in Acute Myeloid Leukemia through a PDGFA-dependent Mechanism.

BACKGROUND: Angiogenesis is a hallmark of cancer, which is regulated by diverse factors, including long non-coding RNAs (lncRNAS). Our previous study showed that the long non-coding RNA H22954 inhibits tumor growth, albeit whether it is involved in the angiogenesis of cancer re-mains unknown. OBJECTIVES: This study aimed to investigate the role of lncRNA H22954 in angiogenesis of acute myeloid leukemia (AML) and the underlying molecular mechanism. METHODS: Bioinformatics analysis was conducted to screen the targeted molecule of H22954. Western blot and ELISA analysis detected PDGFA protein expression, and RT-qPCR detected H22954 and PDGFA expression in cell lines and AML samples. Dual-luciferase reporter gene assay and half-life assay were applied to validate the relationship between H22954 and PDGFA. The functional experi-ment was conducted to investigate the role of H22954 in tube formation. RESULTS: Overexpression of H22954 inhibited angiogenesis in mouse xenograft tumors and cultured acute myeloid leukemia (AML) cells. Bioinformatics analysis and luciferase assay revealed that H22954 targeted the 3' untranslated region (UTR) of the platelet-derived growth factor subunit A (PDGFA) gene. In transfected cells, H22954 overexpression reduced PDGFA expression and protein levels. Tube formation was rescued following the addition of exogenous human PDGFA to the con-ditioned medium from cells overexpressing H22954. The expression of H22954 in K562 cells re-duced the half-life of PDGFA mRNA. Furthermore, H22954 expression was inversely correlated with PDGFA expression in patient samples. CONCLUSION: These findings indicate that H22954 inhibits angiogenesis in AML through the down-regulation of PDGFA expression. Administering recombinant lncRNA H22954 may be a therapeutic approach for patients with AML.

Comparing the standard surgical dressing with dehydrated amnion and platelet-derived growth factor dressings in the healing rate of diabetic foot ulcer: A randomized clinical trial.

AIMS: The management of diabetic foot ulcers is a challenging issue due to the pathophysiological background, delay in healing, and prevalence of diabetes. The purpose of this study was to compare the therapeutic effects of the three methods of diabetic wound care: surgical debridement and dressing, dressing with dehydrated amnion powder, and dressing with platelet-derived growth factor gel. METHODS: In this multi-arm parallel-group randomized trial, 243 patients with a minimum 4-week medical history of diabetic foot ulcers with Wagner's grades 1 and 2, no infection, and adequate tissue blood flow were randomly assigned to one of three 81-person groups: surgical debridement (the standard method), dehydrated amnion dressing, or platelet-derived growth factor dressing. The follow-up period lasted 12 weeks. The percentage area reduction (PAR) was measured as the final target. SPSS version 25 was used to perform statistical analysis on the data. RESULTS: All three study groups were comparable in terms of the type of ulcer, the area of ulcer, Wagner's grade, the period, and the ulcer's size. The PAR in the surgical debridement, platelet-derived growth factor, and dehydrated amnion groups were 7.4%, 14.8%, and 49.3% in week 4; 20.1%, 35.8%, and 79% in week 6; 43.7%, 56.8%, 86.4% in week 8; and 50%, 61.7%, and 87.6% in weeks 10 and 12, respectively. The observed differences were statistically significant (p < 0.05) over the entire period. CONCLUSION: The study concluded that dehydrated amnion dressing, when compared to platelet-derived growth factor dressing and surgical debridement, resulted in better-improved healing in diabetic foot ulcer patients.

Estimulación facial con factores de crecimiento plaquetario en consulta de Dermatología / Facial stimulation with platelet growth factors in Dermatology consultation

RESUMEN El envejecimiento es un proceso complejo que trae consigo cambios celulares, histológicos y cutáneos. Estos últimos son una de sus manifestaciones más evidentes. El plasma rico en plaquetas es una fuente fiable de obtención de células para regenerar tejidos; por su fácil disponibilidad es un material inocuo. La bioestimulación con el mismo, por su parte, es un conjunto de procedimientos para activar las funciones anabólicas de los fibroblastos, producción de colágeno, elastina y ácido hialurónico. La tendencia al empleo de este en tratamientos antiedad es cada vez mayor. El objetivo de este trabajo fue realizar una actualización del tema, para exponer aspectos importantes sobre formas de aplicación, indicaciones, complicaciones y contraindicaciones. Existen varios métodos para la bioestimulación facial, tales como la realización de pápulas, napagge y retroinyección. Se han empleado en alopecia androgénica, areata, envejecimiento cutáneo, etc. Las complicaciones más observadas son dolor, eritema, ardor y sangrado local. Entre las contraindicaciones más comunes se observan el herpes simple recidivante, coagulopatías, tratamiento con anticoagulantes, colagenopatías y neoplasias (AU).

ABSTRACT Aging is a complex process that brings with it cellular, histological and cutaneous changes, the latter being one of its most obvious manifestations. Platelet-rich plasma is a reliable source of cells to regenerate tissues; due to its easy availability, it is a harmless material. Bio-stimulation with it is a set of procedures to activate the fibroblasts anabolic functions and the production of collagen, elastin and hyaluronic acid. The tendency to use it in anti-aging treatments increases faster and faster. The objective of this work was updating the topic to expose important aspects about application methods, indications, complications and contraindications. There are several methods of applying facial bio-stimulation such as performing papules, napagge, and retroinjection. It has been used in androgenic alopecia, alopecia areata, cutaneous ageing, etc. The most commonly found complications are pain, erythema, burning and local bleeding. The most common contraindications include recidivist herpes simplex, coagulopaties, anticoagulant treatment, collagen-related diseases and neoplasms (AU).

Role of platelet-derived growth factor in type II diabetes mellitus and its complications.

Type 2 diabetes mellitus is a type of metabolic disorder characterized by hyperglycaemia with multiple serious complications, such as diabetic neuropathies, diabetic nephropathy, diabetic retinopathy, and diabetic foot. Platelet-derived growth factors are growth factors that regulate cell growth and division, playing a critical role in diabetes and its harmful complications. This review focused on the cellular mechanism of platelet-derived growth factors and their receptors on diabetes development. Furthermore, we raise some proper therapeutic molecular targets for the treatment of diabetes and its complications.

Characteristics of autologous protein solution and leucocyte-poor platelet-rich plasma for the treatment of osteoarthritis of the knee.

Recently, platelet-rich plasma (PRP) has received attention as a treatment for patients with osteoarthritis of the knee (OAK), a chronic degenerative disease, to bridge the gap between conservative and surgical treatments. Here, we investigated the differences in the humoral factors present in two types of PRP purified using the Autologous Protein Solution (APS) kit (group Z; leucocyte-rich PRP) or the Cellaid Serum Collection Set P type (group J; leucocyte-poor [LP]-PRP). Differences in humoral factors between healthy subjects (n = 10) and OAK patients (n = 12; group Z = 6, group J = 6), and the relationship between humoral factors and clinical outcome scores were investigated. Both anti-inflammatory and inflammatory cytokines were highly enriched in APS. The concentrations of tumour necrosis factor (TNF)-α, platelet-derived growth factor, fibroblast growth factor, soluble TNF-receptor 2, soluble Fas and transforming growth factor-ß1 were higher in group Z, while the total amounts were higher in group J. The concentration of interleukin-1 receptor antagonist was positively correlated with the magnitude of change in the clinical outcome score and may contribute to improving knee-joint function. This is the first description of the humoral factors in APS and LP-PRP prepared from healthy subjects or OAK patients of Asian descent.

Platelet-derived growth factor-AB improves scar mechanics and vascularity after myocardial infarction.

Therapies that target scar formation after myocardial infarction (MI) could prevent ensuing heart failure or death from ventricular arrhythmias. We have previously shown that recombinant human platelet-derived growth factor-AB (rhPDGF-AB) improves cardiac function in a rodent model of MI. To progress clinical translation, we evaluated rhPDGF-AB treatment in a clinically relevant porcine model of myocardial ischemia-reperfusion. Thirty-six pigs were randomized to sham procedure or balloon occlusion of the proximal left anterior descending coronary artery with 7-day intravenous infusion of rhPDGF-AB or vehicle. One month after MI, rhPDGF-AB improved survival by 40% compared with vehicle, and cardiac magnetic resonance imaging showed left ventricular (LV) ejection fraction improved by 11.5%, driven by reduced LV end-systolic volumes. Pressure volume loop analyses revealed improved myocardial contractility and energetics after rhPDGF-AB treatment with minimal effect on ventricular compliance. rhPDGF-AB enhanced angiogenesis and increased scar anisotropy (high fiber alignment) without affecting overall scar size or stiffness. rhPDGF-AB reduced inducible ventricular tachycardia by decreasing heterogeneity of the ventricular scar that provides a substrate for reentrant circuits. In summary, we demonstrated that rhPDGF-AB promotes post-MI cardiac wound repair by altering the mechanics of the infarct scar, resulting in robust cardiac functional improvement, decreased ventricular arrhythmias, and improved survival. Our findings suggest a strong translational potential for rhPDGF-AB as an adjunct to current MI treatment and possibly to modulate scar in other organs.

Skeletal Stem Cell-Schwann Cell Circuitry in Mandibular Repair.

Regenerative paradigms exhibit nerve dependency, including regeneration of the mouse digit tip and salamander limb. Denervation impairs regeneration and produces morphological aberrancy in these contexts, but the direct effect of innervation on the stem and progenitor cells enacting these processes is unknown. We devised a model to examine nerve dependency of the mouse skeletal stem cell (mSSC), the progenitor responsible for skeletal development and repair. We show that after inferior alveolar denervation, mandibular bone repair is compromised because of functional defects in mSSCs. We present mSSC reliance on paracrine factors secreted by Schwann cells as the underlying mechanism, with partial rescue of the denervated phenotype by Schwann cell transplantation and by Schwann-derived growth factors. This work sheds light on the nerve dependency of mSSCs and has implications for clinical treatment of mandibular defects.

The positive impact of platelet-derived growth factor on the repair of full-thickness defects of articular cartilage.

OBJECTIVES: This study aims to investigate the potential use and histological effects of the local administration of platelet-derived growth factor (PDGF) in the repair of full-thickness osteochondral defects in articular cartilage in an animal model. MATERIALS AND METHODS: Twenty-four adolescent 18-week-old New Zealand White rabbits with an average weight of 2500 g (range, 1600 g to 3200 g) were used in the study. The rabbits were randomly divided into three groups (n=8) as the control group (group A) and two experimental groups (groups B and C). Defects of cylindrical full-thickness (3.5 mm wide, 4 mm deep) were created in the weight-bearing area of the right knee medial femoral condyles. In group A, the defect was left empty. In group B, the defect was filled with a collagen sponge. In group C, the defect was filled with a collagen sponge impregnated with PDGF. All rabbits were followed-up for 12 weeks. Right knee medial femoral condyles were used for macroscopic and histological analyses. RESULTS: At macroscopic level, the repair tissue was similar to normal adjacent cartilage at 12 weeks in group C. The surface of the repair tissue in group C was smoother and more regular compared to groups A and B. The total histological score of defects in group C was statistically significantly superior compared to groups A and B (p<0.05). Matrix staining and immunostaining of collagen type 2 were stronger in group C compared to the other groups, indicating the presence of a tissue similar to a normal cartilage. CONCLUSION: Platelet-derived growth factor can induce repair in full-thickness defects of articular cartilage in an animal model. Thus, this study demonstrates the potential use of PDGF for full-thickness osteochondral defects.

Optimizing Results in Diabetic Charcot Reconstruction.

Reconstruction of the diabetic Charcot foot can be a challenge even for the most experienced foot and ankle surgeon. The first portion of this article discusses the preoperative evaluation with an emphasis on factors that can be modified before surgical reconstruction to help optimize surgical results. The second portion of the article focuses on intraoperative methods and techniques to help improve postoperative outcomes. Surgeons should strive to provide high-quality, cost-effective care by optimizing patient selection and perioperative care. Objective measures of patient outcomes will become increasingly important with the transition from volume-based to value-based care.

Long-term local PDGF delivery using porous microspheres modified with heparin for tendon healing of rotator cuff tendinitis in a rabbit model.

In this study, we prepared the platelet-derived growth factor-containing porous microspheres modified with heparin (PDGF/Hep-PMSs) and investigated their anti-inflammatory and tendon healing effects on rotator cuff (RC) tendinitis rabbit model. PDGF/Hep-PMSs suppressed the mRNA levels of six pro-inflammatory cytokines (i.e., MMP-3, MMP-13, COX-2, ADAMTS-5, IL-6, and TNF-α) in inflamed tenocytes. Long-term local delivery of PDGF/Hep-PMSs into tendon tissues of RC tendinitis decreased the mRNA levels of six pro-inflammatory cytokines and increased the mRNA levels of anti-inflammatory cytokines including IL-4, IL-10, and IL-13. Anti-inflammatory effects of PDGF/Hep-PMSs might have contributed to enhance the collagen content, tenogenic markers, stiffness, and tensile strength of tendons, eventually leading to tendon restoration. Our findings suggest that the long-term local PDGF delivery of PDGF/Hep-PMSs have a great potential to enhance tendon healing of RC tendinitis by suppressing inflammation responses.

Use of stem cells and growth factors in rotator cuff tendon repair.

The management of rotator cuff tears continues to prove challenging for orthopaedic surgeons. Such tears affect most age groups and can lead to significant morbidity in patients. The aetiology of these tears is likely to be multifactorial; however, an understanding of the mechanisms involved is still under review. Despite advancements in surgical operative techniques and the materials used, post-operative recurrence rates after surgical repair remain high. A growing area of research surrounds biological adjuncts used to improve the healing potential of the repaired tissues. This review of recent publications focuses on the strengths and limitations of using stem cells and growth factors in rotator cuff repair.