Growth factors and cutaneous wound repair

Biological processes and factors involved in soft and hard tissue healing

Wound healing is a complex and iterative process involving myriad cellular and biologic processes that are highly regulated to allow satisfactory repair and regeneration of damaged tissues. This review is intended to be an introductory chapter in a volume focusing on the use of platelet concentrates for tissue regeneration. In order to fully appreciate the clinical utility of these preparations, a sound understanding of the processes and factors involved in soft and hard tissue healing. This encompasses an appreciation of the cellular and biological mediators of both soft and hard tissues in general as well as specific consideration of the periodontal tissues. In light of good advances in this basic knowledge, there have been improvements in clinical strategies and therapeutic management of wound repair and regeneration. The use of platelet concentrates for tissue regeneration offers one such strategy and is based on the principles of cellular and biologic principles of wound repair discussed in this review.

Applications of blood plasma derivatives for cutaneous wound healing: A mini-review of clinical studies

Skin injuries are a global healthcare problem. Chronic ulcers do not heal in a timely fashion, so it is essential to help the body with skin repair. There are some treatments that have been applied to chronic ulcers. One of these treatments is growth factor (GF) therapy. Platelet-rich plasma (PRP) and Platelet-poor plasma (PPP) are two types of plasma derivatives containing many GFs important for wound healing. Several works have reported their application in wound healing and tissue regeneration. The use of autologous PRP is now an adequate alternative in regenerative medicine. It was also demonstrated that PPP is a hemostatic agent for wounds. This review has studied the latest clinical studies, which have applied PRP and PPP to patients with chronic wounds.

CXCL8 and the peritoneal metastasis of ovarian and gastric cancer

CXCL8 is the most representative chemokine produced autocrine or paracrine by tumor cells, endothelial cells and lymphocytes. It can play a key role in normal tissues and tumors by activating PI3K-Akt, PLC, JAK-STAT, and other signaling pathways after combining with CXCR1/2. The incidence of peritoneal metastasis in ovarian and gastric cancer is extremely high. The structure of the peritoneum and various peritoneal-related cells supports the peritoneal metastasis of cancers, which readily produces a poor prognosis, low 5-year survival rate, and the death of patients. Studies show that CXCL8 is excessively secreted in a variety of cancers. Thus, this paper will further elaborate on the mechanism of CXCL8 and the peritoneal metastasis of ovarian and gastric cancer to provide a theoretical basis for the proposal of new methods for the prevention, diagnosis, and treatment of cancer peritoneal metastasis.

Effect of cellular communication network factor 2/connective tissue growth factor on tube formation by endothelial cells derived from human periodontal ligaments

OBJECTIVES

To clarify the role of cellular communication network factor 2/connective tissue growth factor (CCN2/CTGF) in periodontal tissue regeneration by investigating, the proliferative and tubulogenic responses of human endothelial cells obtained from the periodontal ligament to CCN2/CTGF.

DESIGN

Endothelial cells were seeded on agar gel medium with or without 50 ng/mL recombinant CCN2/CTGF (rCCN2/CTGF) and cultured for 6 h. Cells were morphologically and phenotypically analyzed by immunofluorescent microscopy. A colorimetric assay was used to evaluate cell proliferation, and transmission electron microscopy (TEM) was used for ultrastructural analysis.

RESULTS

The proliferation of endothelial cells was best promoted by rCCN2/CTGF at 50 ng/mL. In the control group, tube formation was not observed within 6 h. In contrast, endothelial cells seeded on the agar with 50 ng/mL rCCN2/CTGF clearly showed proliferation with network formation. Under a two-dimensional culture condition, a dense network of endothelial cells was not constructed on the plastic bottom. However, drastic morphological change was observed in the endothelial cells on the agar containing rCCN2/CTGF. The endothelial cells in the dense network were interconnected with each other and showed a tube-like structure. Tight junctions or adherens junctions were observed between the adjoining endothelial cells in the dense network.

CONCLUSIONS

CCN2/CTGF was found to promote the proliferation and tubulogenesis of endothelial cells from the periodontal ligament. These results suggest that CCN2/CTGF may contribute to the regeneration of damaged periodontal tissue by activating the remaining endothelial cells.

Mathematical Modeling Can Advance Wound Healing Research

Significance: For over 30 years, there has been sustained interest in the development of mathematical models for investigating the complex mechanisms underlying each stage of the wound healing process. Despite the immense associated challenges, such models have helped usher in a paradigm shift in wound healing research. Recent Advances: In this article, we review contributions in the field that span epidermal, dermal, and corneal wound healing, and treatments of nonhealing wounds. The recent influence of mathematical models on biological experiments is detailed, with a focus on wound healing assays and fibroblast-populated collagen lattices. Critical Issues: We provide an overview of the field of mathematical modeling of wound healing, highlighting key advances made in recent decades, and discuss how such models have contributed to the development of improved treatment strategies and/or an enhanced understanding of the tightly regulated steps that comprise the healing process. Future Directions: We detail some of the open problems in the field that could be addressed through a combination of theoretical and/or experimental approaches. To move the field forward, we need to have a common language between scientists to facilitate cross-collaboration, which we hope this review can support by highlighting progress to date.

Current applications of platelet gels in wound healing-A review

Human platelets play important roles in several physiologic and pathologic processes. Platelet concentrates are activated with thrombin or calcium, resulting in a viscous coagulum (platelet gel [PG]), composed of 95% platelets at least. PG is increasingly used for the treatment of a variety of soft and hard tissue defects, most notably in the management of chronic non-healing wounds. During wound healing, platelets not only play a critical role in primary hemostasis and thrombosis, but also release growth factors and cytokines to promote tissue regeneration, enhance collagen synthesis, and trigger an immune response. This review addresses a variety of aspects relevant to the functions of well-known platelet growth factors, animal and clinical studies of PG in the last decade, and different sources of platelets for PG. PG is used for non-healing chronic wounds, such as oral ulcerations related to epidermolysis bullosa and chronic graft-versus-host disease, for those, the traditional treatment effect is poor. PG maybe provide a new therapeutic direction for these diseases. Nevertheless, some uncertainty is present, the number of clinical studies is not enough. Hence, randomized controlled trials are still required to study the potential of the use of PG in the near future.

Umbilical cord-derived mesenchymal stem cells preconditioned with isorhamnetin: potential therapy for burn wounds

BACKGROUND

Impaired wound healing can be associated with different pathological states. Burn wounds are the most common and detrimental injuries and remain a major health issue worldwide. Mesenchymal stem cells (MSCs) possess the ability to regenerate tissues by secreting factors involved in promoting cell migration, proliferation and differentiation, while suppressing immune reactions. Preconditioning of MSCs with small molecules having cytoprotective properties can enhance the potential of these cells for their use in cell-based therapeutics.

AIM

To enhance the therapeutic potential of MSCs by preconditioning them with isorhamnetin for second degree burn wounds in rats.

METHODS

Human umbilical cord MSCs (hU-MSCs) were isolated and characterized by surface markers, CD105, vimentin and CD90. For preconditioning, hU-MSCs were treated with isorhamnetin after selection of the optimized concentration (5 µmol/L) by cytotoxicity analysis. The migration potential of these MSCs was analyzed by the in vitro scratch assay. The healing potential of normal, and preconditioned hU-MSCs was compared by transplanting these MSCs in a rat model of a second degree burn wound. Normal, and preconditioned MSCs (IH + MSCs) were transplanted after 72 h of burn injury and observed for 2 wk. Histological and gene expression analyses were performed on day 7 and 14 after cell transplantation to determine complete wound healing.

RESULTS

The scratch assay analysis showed a significant reduction in the scratch area in the case of IH + MSCs compared to the normal untreated MSCs at 24 h, while complete closure of the scratch area was observed at 48 h. Histological analysis showed reduced inflammation, completely remodeled epidermis and dermis without scar formation and regeneration of hair follicles in the group that received IH + MSCs. Gene expression analysis was time dependent and more pronounced in the case of IH + MSCs. Interleukin (IL)-1β, IL-6 and Bcl-2 associated X genes showed significant downregulation, while transforming growth factor β, vascular endothelial growth factor, Bcl-2 and matrix metallopeptidase 9 showed significant upregulation compared to the burn wound, showing increased angiogenesis and reduced inflammation and apoptosis.

CONCLUSION

Preconditioning of hU-MSCs with isorhamnetin decreases wound progression by reducing inflammation, and improving tissue architecture and wound healing. The study outcome is expected to lead to an improved cell-based therapeutic approach for burn wounds.

Wound healing potentials of herbal ointment containing Calendula officinalis Linn. on the alteration of immunological markers and biochemical parameters in excision wounded animals

Objective

The present study was designed to investigate the in vivo wound healing activity of herbal ointment prepared fromCalendula officinalisLinn. on excision wounded rats.

Materials and methods

The excision wound model was employed for wound healing activity in albino rats. Healthy albino rats (150–200 g) of either sex were taken for excision wound model. Animals were divided into five groups of six animals in each. Group I served as normal control, Group II served as excision wounded control without treatment and Group III, IV served as excision wounded rats were treated with herbal ointment of two different doses (10% and 20%) applied topically for 14 days and group V served as excision wounded animals treated with reference ointment soframycin. Healing potential was evaluated by the rate of wound contraction, immunological markers like IL-6(Interleukin 6), TNF-alpha (Tumor necrosis factor -α), PDGF (Platelet Derived Growth Factor) and EGF (Epidermal Growth Factor), lipid peroxide (LPO), superoxide dismutase (SOD), and biochemical parameters like hydroxyproline, hesosamine, and tissue protein.

Results

The topical application of herbal ointment treated groups showed increase in the levels of growth factors such as PDGF and EGF hydroxy proline, hesosamine, tissue protein, SOD and wound contraction and the ointment normalized the levels of lipid peroxide, IL-6, TNF-alpha compared than that of excision wounded animals.

Conclusion

From the above results, it was concluded that the topical application of herbal ointment exhibited significant wound healing activity in excision wounded rats as evidenced by increased wound contraction and collagen synthesis.

Nutritional interventions for treating foot ulcers in people with diabetes

BACKGROUND

Foot ulcers in people with diabetes are non-healing, or poorly healing, partial, or full-thickness wounds below the ankle. These ulcers are common, expensive to manage and cause significant morbidity and mortality. The presence of a wound has an impact on nutritional status because of the metabolic cost of repairing tissue damage, in addition to the nutrient losses via wound fluid. Nutritional interventions may improve wound healing of foot ulcers in people with diabetes.

OBJECTIVES

To evaluate the effects of nutritional interventions on the healing of foot ulcers in people with diabetes.

SEARCH METHODS

In March 2020 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that evaluated the effect of nutritional interventions on the healing of foot ulcers in people with diabetes.

DATA COLLECTION AND ANALYSIS

Two review authors, working independently, assessed included RCTs for their risk of bias and rated the certainty of evidence using GRADE methodology, using pre-determined inclusion and quality criteria.

MAIN RESULTS

We identified nine RCTs (629 participants). Studies explored oral nutritional interventions as follows: a protein (20 g protein per 200 mL bottle), 1 kcal/mL ready-to-drink, nutritional supplement with added vitamins, minerals and trace elements; arginine, glutamine and β-hydroxy-β-methylbutyrate supplement; 220 mg zinc sulphate supplements; 250 mg magnesium oxide supplements; 1000 mg/day omega-3 fatty acid from flaxseed oil; 150,000 IU of vitamin D, versus 300,000 IU of vitamin D; 250 mg magnesium oxide plus 400 IU vitamin E and 50,000 IU vitamin D supplements. The comparator in eight studies was placebo, and in one study a different dose of vitamin D. Eight studies reported the primary outcome measure of ulcer healing; only two studies reported a measure of complete healing. Six further studies reported measures of change in ulcer dimension, these studies reported only individual parameters of ulcer dimensions (i.e. length, width and depth) and not change in ulcer volume. All of the evidence identified was very low certainty. We downgraded it for risks of bias, indirectness and imprecision. It is uncertain whether oral nutritional supplement with 20 g protein per 200 mL bottle, 1 kcal/mL, nutritional supplement with added vitamins, minerals and trace elements, increases the proportion of ulcers healed at six months more than placebo (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.42 to 1.53). It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases the proportion of ulcers healed at 16 weeks compared with placebo (RR 1.09, 95% CI 0.85 to 1.40). It is uncertain whether the following interventions change parameters of ulcer dimensions over time when compared with placebo; 220 mg zinc sulphate supplement containing 50 mg elemental zinc, 250 mg magnesium oxide supplement, 1000 mg/day omega-3 fatty acid from flaxseed oil supplement, magnesium and vitamin E co-supplementation and vitamin D supplementation. It is also uncertain whether 150,000 IU of vitamin D, impacts ulcer dimensions when compared with 300,000 IU of vitamin D. Two studies explored some of the secondary outcomes of interest for this review. It is uncertain whether oral nutritional supplement with 20 g protein per 200 mL bottle, 1 kcal/mL, nutritional supplement with added vitamins, minerals and trace elements, reduces the number of deaths (RR 0.96, 95% CI 0.06 to 14.60) or amputations (RR 4.82, 95% CI 0.24 to 95.88) more than placebo. It is uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement increases health-related quality of life at 16 weeks more than placebo (MD -0.03, 95% CI -0.09 to 0.03). It is also uncertain whether arginine, glutamine and β-hydroxy-β-methylbutyrate supplement reduces the numbers of new ulcers (RR 1.04, 95% CI 0.71 to 1.51), or amputations (RR 0.66, 95% CI 0.16 to 2.69) more than placebo. None of the included studies reported the secondary outcomes cost of intervention, acceptability of the intervention (or satisfaction) with respect to patient comfort, length of patient hospital stay, surgical interventions, or osteomyelitis incidence. One study exploring the impact of arginine, glutamine and β-hydroxy-β-methylbutyrate supplement versus placebo did not report on any relevant outcomes.

AUTHORS' CONCLUSIONS

Evidence for the impact of nutritional interventions on the healing of foot ulcers in people with diabetes compared with no nutritional supplementation, or compared with a different dose of nutritional supplementation, remains uncertain, with eight studies showing no clear benefit or harm. It is also uncertain whether there is a difference in rates of adverse events, amputation rate, development of new foot ulcers, or quality of life, between nutritional interventions and placebo. More research is needed to clarify the impact of nutritional interventions on the healing of foot ulcers in people with diabetes.

A novel lidocaine hydrochloride mucoadhesive films for periodontal diseases

Periodontal diseases are inflammatory disorders caused primarily by dental plaque microorganisms that even may need surgery to remove damaged tissue. Adhesive biocompatible films may be an adequate form in order to improve drug retention or prevent microbial infections by covering the surgical site. In recent years, much attention has been focused on biocompatible inexpensive polymers, for biomedical and pharmaceutical potential applications. The objective of this research is the development of a film for mucosal application containing lidocaine hydrochloride (5%, w/w) as anesthetic drug. Lidocaine films were prepared with three biopolymers: hydroxypropylmethylcellulose (HPMC), chitosan (CH), or xanthan gum (XG). Their thickness and uniformity content were characterized. Rheological behavior of the hydrated films was studied using flow curves, creep and recovery tests and dynamic oscillatory measurements with a rheometer. The mucoadhesive assays were carried out with cheeks of Wistar rat using a universal tensile tester to know their adhesiveness. Finally, lidocaine delivery through the films was investigated in Franz cells. All films (n = 3 for each polymer) showed flexibility, a drug content of 0.015 ± 0.001 g/cm² and a thickness of 0.25 ± 0.01 mm. The results of the maximum detachment force in tensile tests and work adhesion indicated that XG is the polymer that showed greater power of mucoadhesion (p < 0.05). These properties show a good correlation with the rheological characteristics. In all cases, the lidocaine amount released at 30 min is around 4 mg/cm². This amount could be considered sufficient to guarantee the anesthetic effect.

Annexin A12-26 Treatment Improves Skin Heterologous Transplantation by Modulating Inflammation and Angiogenesis Processes

Skin graft successful depends on reduction of local inflammation evoked by the surgical lesion and efficient neovascularization to nutrition the graft. It has been shown that N-terminal portion of the Annexin A1 protein (AnxA1) with its anti-inflammatory properties induces epithelial mucosa repair and presents potential therapeutic approaches. The role of AnxA1 on wound healing has not been explored and we investigated in this study the effect of the peptide Ac2-26 (N-terminal AnxA1 peptide Ac2-26; AnxA1_2-26) on heterologous skin scaffolds transplantation in BALB/c mice, focusing on inflammation and angiogenesis. Treatment with AnxA1_2-26, once a day, from day 3-60 after scaffold implantation improved the take of the implant, induced vessels formation, enhanced gene and protein levels of the vascular growth factor-A (VEGF-A) and fibroblast influx into allograft tissue. It also decreased pro- while increasing anti-inflammatory cytokines. The pro-angiogenic activity of AnxA1_2-26 was corroborated by topical application of AnxA1_2-26 on the subcutaneous tissue of mice. Moreover, treatment of human umbilical endothelial cells (HUVECs) with AnxA1_2-26 improved proliferation, shortened cycle, increased migration and actin polymerization similarly to those evoked by VEGF-A. The peptide treatment instead only potentiated the tube formation induced by VEGF-A. Collectively, our data showed that AnxA1_2-26 treatment favors the tissue regeneration after skin grafting by avoiding exacerbated inflammation and improving the angiogenesis process.

Mucosal co-delivery of ketorolac and lidocaine using polymeric wafers for dental application

The current study aimed to investigate the effectiveness of a developed sodium alginate and polyvinylpyrrolidone K-25 (PVP K-25) polymeric wafer for the co-delivery of ketorolac and lidocaine to soft tissues for healing and pain control following gingivectomy. Nine ketorolac/lidocaine lyophilized wafers were formulated and assessed for their hydration capacity, mucoadhesion ability and in vitro release profile to select the optimum system for further clinical investigation. Wafer F6 containing 2:1 sodium alginate to PVP K-25 and 10% glycerol showed optimum properties and was selected for the clinical study. Twenty patients were included in the study and the ketorolac/lidocaine wafer was assessed versus a market product. Visual pain analog was evaluated daily for the first week and wound healing index was evaluated for one week, two weeks and one month following the procedure. The developed ketorolac/lidocaine polymeric wafer proved to be an effective method of reducing pain and discomfort together with enhancing wound healing following gingivectomy.

Diabetex: A novel approach for diabetic wound healing

INTRODUCTION AND AIM

Wound healing is an orderly complex process involving inflammation, clotting, re-epithelialization, neovascularization and wound closure. In diabetic patients, such process is impaired and delayed, posing negative economic as well as social consequences. Diabetex, (patency# EP 0877617 A1) composed of L-alanine, d-ribose, nicotinic acid and calcium ascorbate, which was initially introduced to treat cancer is thought to have anti- diabetic effects. The present study was designed to investigate the therapeutic merit of diabetex as well as the cellular mechanisms involved in such effects and its safety profile compared to metformin in wounded diabetic rats.

MAIN METHODS

Sixty adult male Sprague-Dawley albino rats were randomly divided into two major groups after induction of full thickness wound; control and treated groups. Liver and kidney function test, as well as cytokines (VEGF, TGF-β, PDGF and MMP2), fasting blood sugar were measured in animal sera. Histopathological studies including hematoxyline and eosin, Masson's trichrome stains were performed on wounded tissue.

KEY FINDINGS

Diabetex significantly improved wound healing, collagen formation, induced re-epithelialization and neovascularization. Moreover, cytokines involved in wound healing process were increased by the antidiabetic medication. Noteworthy, the drug exhibited a safe profile on liver and kidney function tests and significantly reduced fasting blood sugar.

SIGNIFICANCE

The present study offers a novel approach for treating diabetic resistant wounds with a possible more economic, safe strategy.

Tissue Regenerating Capacity of Carbodiimide-Crosslinked Dermal Sheep Collagen during Repair of the Abdominal Wall

In future, the function of collagen-based biomaterials as temporary scaffolds for the generation of new tissue may be emphasized. In this study the function of dermal sheep collagen (DSC) crosslinked with carbodiimide (ENDSC) as repair material for abdominal wall defects in rats was compared with that of commercial hexamethylenediisocyanate-crosslinked HDSC. The results indicate that early after implantation both ENDSC and HDSC functioned well as a matrix for cellular ingrowth. However during further implantation HDSC soon degraded resulting in herniations, while ENDSC showed a delay in the degradation time of at least 20 weeks. ENDSC thereby enabled collagen new-formation and functioned as a guidance for muscle overgrowth. These results are very promising concerning the problem of the ongoing foreign body reaction with continuing risk of implant rejection observed in clinical practice with non-degradable materials.

Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction

A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis.

Nonoperative Management of Venous Leg Ulcers: Evolving Role of Skin Substitutes

Chronic venous leg ulcers markedly influence the physical, financial, and psychologic wellbeing of patients and result in an estimated 2 million lost workdays annually. Despite a wide variety of therapeutic options, venous leg ulcers remain a substantial management challenge to health care professionals. Although no consensus on compression therapy exists, it remains a primary treatment of edema and ulceration secondary to venous disease. Recently, biotechnology-derived skin substitutes have been developed to help stimulate local wound healing. These range in composition from an epidermal or dermal layer to a complete, bilayered living skin construct. This review focuses on nonoperative treatment options for venous ulcers, particularly the evolving roles of newer treatment options including skin substitutes and growth factor/cytokine preparations. The development and characteristics of these emerging therapies as well as clinical experience with and options for their use in the treatment of chronic venous ulcers are reviewed.

A novel chemo-mechano-biological model of arterial tissue growth and remodelling

Arterial growth and remodelling (G&R) is mediated by vascular cells in response to their chemical and mechanical environment. To date, mechanical and biochemical stimuli tend to be modelled separately, however this ignores their complex interplay. Here, we present a novel mathematical model of arterial chemo-mechano-biology. We illustrate its application to the development of an inflammatory aneurysm in the descending human aorta. The arterial wall is modelled as a bilayer cylindrical non-linear elastic membrane, which is internally pressurised and axially stretched. The medial degradation that accompanies aneurysm development is driven by an inflammatory response. Collagen remodelling is simulated by adaption of the natural reference configuration of constituents; growth is simulated by changes in normalised mass-densities. We account for the distribution of attachment stretches that collagen fibres are configured to the matrix and, innovatively, allow this distribution to remodel. This enables the changing functional role of the adventitia to be simulated. Fibroblast-mediated collagen growth is represented using a biochemical pathway model: a system of coupled non-linear ODEs governs the evolution of fibroblast properties and levels of key biomolecules under the regulation of Transforming Growth Factor (TGF)-β, a key promoter of matrix deposition. Given physiologically realistic targets, different modes of aneurysm development can be captured, while the predicted evolution of biochemical variables is qualitatively consistent with trends observed experimentally. Interestingly, we observe that increasing the levels of collagen-promoting TGF-β results in arrest of aneurysm growth, which seems to be consistent with experimental evidence. We conclude that this novel Chemo-Mechano-Biological (CMB) mathematical model has the potential to provide new mechanobiological insight into vascular disease progression and therapy.

Rumen tissue derived decellularized submucosa collagen or its chitosan-treated film as a cutaneous wound healant and 1H NMR-metabolite profiling of plasma

Developing an ideal wound dressing material for skin defects is of significant importance in a clinical emergency and is currently a global burden.

Efficacy of gelatin gel sheets sustaining epidermal growth factor for murine skin defects

BACKGROUND

Epidermal growth factor (EGF) plays an important role in wound healing. However, EGF must be applied daily due to rapid inactivation in vivo. We investigated the sustained release of EGF from gelatin gel sheets (GGSs) and the efficacy of GGSs impregnated with EGF for promoting wound healing.

MATERIALS AND METHODS

GGSs impregnated with EGF were prepared by cross-linking via glutaraldehyde to gelatin solution containing EGF. The sustained release of EGF and the bioactivity of released EGF were evaluated. Then, three kinds of GGSs containing NSS (normal saline solution; NSS group), 2.5 μg of EGF (EGF-L group), or 25 μg of EGF (EGF-H group) were applied to full-thickness skin defects created on the backs of mice. The wounds covered with polyurethane film without GGS were used as a control (PUF group). The wound area, neoepithelium length, regenerated granulation tissue, and newly formed capillaries were evaluated.

RESULTS

EGF was sustained and released from GGS as it degraded. The bioactivity of released EGF was confirmed. EGF-L group promoted the neoepithelium length, regenerated granulation tissue, and newly formed capillaries compared with those in the PUF and NSS groups. The area of regenerated granulation tissue in the NSS group (week 1: 2.6 + 0.2 mm(2), week 2: 2.8 + 0.3 mm(2)) was larger than that in the PUF group (week 1: 0.6 + 0.1 mm(2), week 2: 1.0 + 0.1 mm(2)). The area of newly formed capillaries in the EGF-L group (9967 + 1903 μm(2)) was larger than that of the EGF-H group (3485 + 1050 μm(2)).

CONCLUSIONS

GGSs impregnated with EGF-L showed promising results regarding wound healing.

Wound healing: a new perspective on glucosylated tetrahydrocurcumin

Wound healing represents a dynamic set of coordinated physiological processes observed in response to tissue injury. Several natural products are known to accelerate the process of wound healing. Tetrahydrocurcumin (THC), an in vivo biotransformed product/metabolite of curcumin, is known to exhibit a wide spectrum of biological activities similar to those of native curcuminoids. The poor bioavailability of these curcuminoids limits their clinical applications. The present study highlights the percutaneous absorption and wound healing activity of glucosyl-conjugated THC (glucosyl-THC) in male Wistar rats. A high plasma concentration of glucosyl-THC (4.35 μg/mL) was found in rats 3 hours after application. A significant enhanced wound healing activity and reduced epithelialization time were observed in rats that received glucosyl-THC. This may have been due to the improved bioavailability of the glucosyl compound. The nonstaining and lack of skin-sensitive side effects render the bioconjugated glucosyl-THC a promising therapeutic compound in the management of excision wounds and in cosmetic applications, in the near future.

Clinical implication of perioperative inflammatory cytokine alteration

Cytokines are key modulators of inflammatory responses, and play an important role in the defense and repair mechanisms following trauma. After traumatic injury, an immuno-inflammatory response is initiated immediately, and cytokines rapidly appear and function as a regulator of immunity. In pathologic conditions, imbalanced cytokines may provide systemic inflammatory responses or immunosuppression. Expression of perioperative cytokines vary by different intensities of surgical trauma and types of anesthesia and anesthetic agents. Inflammatory cytokines play important roles in postoperative organ dysfunction including central nervous system, cardiovascular, lung, liver, and kidney injury. Inhibition of cytokines could protect against traumatic injury in some circumstances, therefore cytokine inhibitors or antagonists might have the potential for reducing postoperative tissue/organ dysfunction. Cytokines are also involved in wound healing and post-traumatic pain. Application of cytokines for the improvement of surgical wound healing has been reported. Anesthesia-related immune response adjustment might reduce perioperative morbidity because it reduces proinflammatory cytokine expression; however, the overall effects of anesthetics on postoperative immune-inflammatory responses needs to be further investigated.

Effectiveness of Platelet-Rich Plasma to Enhance Healing of Diabetic Foot Ulcers in Patients With Concomitant Peripheral Arterial Disease and Critical Limb Ischemia

We sought to investigate the effect of autologous platelet-rich plasma (PRP) on the healing rate of diabetic foot ulcers in patients with diabetes and concomitant peripheral arterial disease (PAD). Diabetic patients with foot ulceration presenting with PAD who were treated with local growth factors in a single center, during a 24-month period from May 2009 to April 2011, were retrospectively reviewed. Based on the severity of PAD, subjects were divided into groups A (Fontaine classification stages I, IIa, and IIb) and B (Fontaine classification stages III and IV), with those included in the latter being considered to suffer from critical limb ischemia (CLI). End points of the analysis were clinical improvement, limb salvage, and amputation rate. Outcome was compared between groups A and B. Overall, 72 patients were evaluated, 30 with CLI. Ulcer area reduction >50% was observed in 58/72 patients while reduction >90% was achieved in 52/72 patients. There were 14 (19%) major and minor amputations, whereas the limb salvage rate was 89%. This variable was significantly different between groups A and B (100% vs. 73%, P < .001), as is rate of reduction in ulcer area >90% (83% vs. 56%, P = .02). Reduction of ulcer area >50% was observed in the majority of patients in both groups (group A 86% vs. group B 73%, P = .23). In conclusion, PRP could serve as a useful adjunct during management of diabetic foot ulcers even in diabetic patients with unreconstructable arterial disease.

Growth factors in wound healing: the present and the future?

Numerous clinical studies have confirmed the pivotal role growth factors play in wound healing and their diminished levels in the chronic wound. Despite promising early studies treating chronic wounds with growth factors, results with traditional bolus dosing of a single growth factor have yielded insignificant results. Disappointing results have been theorized to be the result of growth factors inherent short half-life, a hostile microenvironment rich in protease activity, and poor delivery mechanisms failing to deliver effective dosages in an appropriate temporal manner. Advances in tissue engineering and regenerative medicine have provided technologies capable of delivering multiple growth factors in a spatially oriented approach. These technologies include polymer systems, scaffolds, and hydrogels that have demonstrated improved response by target tissues when growth factors are delivered in this biomimetic fashion. With improved delivery systems, treatment of chronic wounds with growth factors has the potential to accelerate healing in a manner not previously realized with traditional delivery approaches.

Deficient repair response of IPF fibroblasts in a co-culture model of epithelial injury and repair

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a progressive disorder marked by relentless fibrosis and damage of the lung architecture. A growing body of evidence now suggests that IPF progresses as a result of aberrant epithelial-fibroblast crosstalk. Injured epithelia are a major source of growth factors such as PDGF which guide resident fibroblasts to injury sites.

RESULTS

In this study, we utilized a novel co-culture system to investigate the effect of fibroblast phenotype on their response to epithelial injury. Fibroblasts from normal lungs (NHLF) responded to epithelial injury and populated the wound site forming a fibroblast plug/mechanical barrier which prevented epithelial wound closure. IPF fibroblasts were impaired in their response to epithelial injury. They also expressed reduced PDGFRα compared to NHLFs and were defective towards PDGF-AA mediated directional movement. Neutralization of PDGF-AA and pan-PDGF but not PDGF-BB reduced the injury response of NHLFs thereby preventing the formation of the mechanical barrier and promoting epithelial wound closure. Co-culture of epithelial cells with IPF fibroblasts led to marked increase in the levels of pro-fibrotic growth factors - bFGF and PDGF and significant depletion of anti-fibrotic HGF in the culture medium. Furthermore, IPF fibroblasts but not NHLFs induced a transient increase in mesenchymal marker expression in the wound lining epithelial cells. This was accompanied by increased migration and faster wound closure in co-cultures with IPF fibroblasts.

CONCLUSIONS

Our data demonstrate that the IPF fibroblasts have an aberrant repair response to epithelial injury.

Dermal templates and the wound-healing paradigm: the promise of tissue regeneration

Dermal regeneration templates arguably represent the first and most clinically successful 'tissue engineering' solution designed for organ reconstruction. Wound healing in the skin normally occurs on a continuum. At one extreme of the continuum lies the promise of tissue regeneration and the complete restoration of normal structure and function. Unfortunately, in the adult, all too often, wound healing occurs at the other extreme of the continuum and the dermis is reconstituted as scar tissue. Dermal regeneration templates are designed to manage the wound-healing process and tip the scales toward regeneration. This review discusses the architecture and molecular composition of the skin and the events that mediate wound healing and scar formation. The development, evolution and commercialization of dermal templates are examined and the clinical and business considerations that drive the product-development cycle are discussed. In the near term, dermal templates cannot be expected to dramatically change in overall composition. Product development will be dominated by continued refinements of existing templates and the field of use will continue to expand as manufacturers seek to increase revenue and capture market share. Continued exploration of novel processing strategies, such as electrospinning, that can be used to fabricate nanoscale biomaterials, may provide a gateway to the next generation of dermal templates.

The selection of peritoneal mesothelial cells is important for cell therapy to prevent peritoneal fibrosis

Long-term peritoneal dialysis (PD) causes chronic peritoneal damage. Peritoneal mesothelial cells (PMCs) play an important role in peritoneal function. We investigated the possibility of cell therapy using the PMCs to prevent peritoneal damage in PD patients. We harvested human PMCs from the PD effluent of PD patients. The PMCs were separated based on morphological characteristics into epithelial-like (Epi) cells and fibroblast-like (Fib) cells by the limiting dilution method. We transplanted these cells into nude mice whose parietal and visceral peritoneum were scratched by mechanical scraping. The transplanted cells were detected at the parietal and visceral peritoneum. Compared with the positive control, the Epi cell therapy group showed very few adhesions and exhibited no thickening of the parietal and visceral peritoneum. However, the group with Fib cell therapy could not inhibit peritoneal adhesion and thickening. In addition, hepatocyte growth factor was expressed by the grafted Epi cells but not Fib cells. Fib cells expressed vascular endothelial growth factor stronger than Epi cells. These two types of cells from the same patient showed different characteristics and effects for cell therapy. These findings suggest that the PMCs from the PD patient showed different characteristics, such as Epi cells and Fib cells, and the selection of PMCs is important for cell therapy on the point of not only the direct cellular interactions but also cytokine secretion from the grafted cells. Furthermore, the differences in the morphological cell characteristics may influence their role in peritoneal regeneration.

Delayed fracture healing in tetranectin-deficient mice

Tetranectin is a plasminogen-binding protein that enhances plasminogen activation, which has been suggested to play a role in tissue remodeling. Recently, we showed that tetranectin has a role in the wound-healing process. In this study, we investigated whether tetranectin plays a role in fracture healing. The fracture-healing process was studied using a femoral osteotomy model in tetranectin-null mice, previously generated by the authors. Radiographic imaging, micro-computed tomography (μCT), and histological analysis were used to evaluate osteotomy healing. In wild-type mice, a callus was apparent from 7 days, and most samples showed marked callus formation and rebridging of the cortices at the osteotomy site at 21 days. In contrast, in the tetranectin-null mice there was no callus formation at 7 days and much less callus formation and no bridging of cortices were observed at 21 days. At 35 days, all osteotomy sites showed clear rebridging, and secondary bone formation was achieved in wild-type mice by 42 days. In contrast, no clear rebridging or secondary bone formation was observed at 42 days in the tetranectin-null mice. Analysis using μCT at 21 days after osteotomy revealed that the callus area in tetranectin-null mice was smaller than that in wild-type mice. Histological analysis also showed that soft tissue and callus formation were smaller in the tetranectin-null mice at the early stage of the healing process after drill-hole injury. These results suggested that tetranectin could have a role in the positive regulation at the early stage of the fracture-healing process, which was reflected in the delayed fracture healing in tetranectin-deficient mice.

Interleukin (IL)-19 promoted skin wound healing by increasing fibroblast keratinocyte growth factor expression

BACKGROUND

Interleukin (IL)-19, a member of the IL-10 cytokine family, is involved in keratinocyte proliferation in psoriasis.

OBJECTIVES

We investigated the role of IL-19 in the wound-healing process in vivo and in vitro.

METHODS

Two full-thickness circular wounds (4mm in diameter) were punched into the skin of BALB/C mice. IL-19 and keratinocyte growth factor (KGF) mRNA in wounded skin were determined using real-time PCR. The wounds were treated with PBS, vehicle, IL-19 (400ng/mL), or IL-20 (400ng/mL) (n=6 in each group) twice daily and the percentage of wound healing was measured daily for 7days. In vitro, human skin fibroblast CCD966-SK cells and keratinocyte HaCaT cells were treated with IL-19 or KGF. Cell proliferation and migration were determined using bromodeoxyuridine (BrdU) and transwell assays, respectively. The expression of IL-19 and KGF mRNA was also analyzed.

RESULTS

In wounded mouse skin, IL-19 mRNA was upregulated at 12h, and KGF at 24h after the injury. Both increases in gene expression declined 72h after the skin had been wounded. The percentage of wound healing in IL-19-treated mice was higher than in control mice. In vitro, IL-19 upregulated KGF expression in the CCD966-SK cells; IL-19 was upregulated in KGF-treated HaCaT cells. KGF but not IL-19 promoted HaCaT cell proliferation. However, IL-19 significantly increased the migration of HaCaT cells. HaCaT cells treated with the cultured supernatants of IL-19-stimulated CCD966-SK cells showed significantly more proliferation than in controls.

CONCLUSIONS

IL-19 is important for cutaneous wound healing because it upregulates KGF expression.

The use of autologous platelet-leukocyte-enriched plasma to minimize drain burden and prevent seroma formation in latissimus dorsi breast reconstruction

INTRODUCTION

Seromas and drains are major sources of morbidity associated with latissimus dorsi breast reconstruction. Our goal was to look at an autologous platelet-leukocyte-enriched plasma spray and to assess its efficacy in reducing drain burden and seroma formation.

METHODS

We performed a single surgeon, patient-controlled, blinded study on bilateral latissimus dorsi breast reconstruction patients in which we applied autologous platelet-leukocyte-enriched plasma to one side and measured drain amounts, time to drain removal, and seroma rate.

RESULTS

Twelve patients were included in this study. The average age was 41.1 years, and the average body mass index was 21.6 kg/m. Average volume of drain output showed neither difference (789 mL spray side vs. 790 mL control side) nor average time to drain removal (11.83 days spray side vs. 11.5 days control side). There were 2 complications reported: 1 hematoma (8.33%) and 1 seroma (8.33%) that required aspiration in a postoperative visit.

CONCLUSIONS

It appears after 12 patients that there is no demonstrable difference regarding drain output, time to drain removal, or seroma incidence between the study and the control group. We feel a larger study population would add power and confirm these findings.

Toxicogenomic analysis of chlorine vapor-induced porcine skin injury

Chlorine is an industrial chemical that can cause cutaneous burns. Understanding the molecular mechanisms of tissue damage and wound healing is important for the selection and development of an effective post-exposure treatment. This study investigated the effect of cutaneous chlorine vapor exposure using a weanling swine burn model and microarray analysis. Ventral abdominal sites were exposed to a mean calculated chlorine vapor concentration of 2.9 g/L for 30 min. Skin samples were harvested at 1.5 h, 3 h, 6 h, and 24 h post-exposure and stored in RNAlater(®) until processing. Total RNA was isolated, processed, and hybridized to Affymetrix GeneChip(®) Porcine Genome Arrays. Differences in gene expression were observed with respect to sampling time. Ingenuity Pathways Analysis revealed seven common biological functions among the top ten functions of each time point, while canonical pathway analysis revealed 3 genes (IL-6, IL1A, and IL1B) were commonly shared among three significantly altered signaling pathways. The transcripts encoding all three genes were identified as common potential therapeutic targets for Phase II/III clinical trial, or FDA-approved drugs. The present study shows transcriptional profiling of cutaneous wounds induced by chlorine exposure identified potential targets for developing therapeutics against chlorine-induced skin injury.

Growth factor release in extra- and intramedullary osteosynthesis following tibial fracture

INTRODUCTION

Recent studies indicate alterations of local and systemic growth factor level during fracture healing. As a result, osteogenic and angiogenic growth factors allow us to monitor fracture healing on a molecular level. We hypothesised that closed intramedullary (IM) reaming and nail fixation, in contrast to open reduction and internal plate fixation (ORIF), could exert an effect on the cellular elements present in the intramedullary canal, leading to increased release of mediators. The purpose of the study was to investigate whether different osteosynthesis techniques influence the released quantity of cytokines.

PATIENTS AND METHODS

A total of 34 patients with tibia fractures treated with IM fixation and 19 patients treated with ORIF were included in the study. In addition to clinical and radiological examination, serum concentrations of transforming growth factor beta 1(TGF-β1), macrophage-colony stimulating factor (M-CSF) and vascular endothelial growth factor (VEGF), were analysed at 1, 2, 4, 6, 8, 12, and 24 weeks after surgery.

RESULTS

Expression of TGF-β1 and M-CSF was increased during the first 2 weeks of fracture healing in patients treated with the IM fixation technique compared with those treated by ORIF. After 24 weeks, M-CSF levels in patients with IM fixation were clearly higher. Conversely, VEGF levels were higher during the first 2 weeks of fracture healing in patients treated by ORIF compared with IM fixation. However, these results were not significant.

CONCLUSION

Our results show that 1 week after surgery neither reamed IM fixation nor ORIF of the tibia could increase the expression of VEGF, M-CSF and TGF-β1 in its favour.

A mathematical model for foreign body reactions in 2D

The foreign body reactions are commonly referred to the network of immune and inflammatory reactions of human or animals to foreign objects placed in tissues. They are basic biological processes, and are also highly relevant to bioengineering applications in implants, as fibrotic tissue formations surrounding medical implants have been found to substantially reduce the effectiveness of devices. Despite of intensive research on determining the mechanisms governing such complex responses, few mechanistic mathematical models have been developed to study such foreign body reactions. This study focuses on a kinetics-based predictive tool in order to analyze outcomes of multiple interactive complex reactions of various cells/proteins and biochemical processes and to understand transient behavior during the entire period (up to several months). A computational model in two spatial dimensions is constructed to investigate the time dynamics as well as spatial variation of foreign body reaction kinetics. The simulation results have been consistent with experimental data and the model can facilitate quantitative insights for study of foreign body reaction process in general.

A Predictive Tool for Foreign Body Fibrotic Reactions Using 2-Dimensional Computational Model

It is well established that implanted medical devices often trigger immunological and inflammatory reactions. Such foreign body-mediated tissue responses may result in fibrotic tissue formation surrounding the implants. Despite of intensive research in the area of wound healing, few methods are currently available to systematically predict the quantitative behavior of the complex system of multiple cells, proteins and enzymes during foreign body-associated fibrotic reactions. This study introduces a kinetics-based predictive tool to analyze outcomes of reactions of various cells/proteins and biochemical processes and to understand transient behavior during the entire implant healing period up to several months in time. A computational model in two spatial dimensions is constructed to investigate the time dynamics as well as spatial variation of fibrotic reaction kinetics. Our results have shown that this model can be used to predict many features in a systematic way and also complement the traditional immunological methodology by experiments or empirical data predictions.

Suppression of LPS-induced matrix-metalloproteinase responses in macrophages exposed to phenytoin and its metabolite, 5-(p-hydroxyphenyl-), 5-phenylhydantoin

BACKGROUND

Phenytoin (PHT) has been reported to induce gingival (gum) overgrowth (GO) in approximately 50% of patients taking this medication. While most studies have focused on the effects of PHT on the fibroblast in the pathophysiology underlying GO, few studies have investigated the potential regulatory role of macrophages in extracellular matrix (ECM) turnover and secretion of proinflammatory mediators. The aim of this study was to evaluate the effects of PHT and its metabolite, 5-(p-hydroxyphenyl-), 5-phenylhydantoin (HPPH) on LPS-elicited MMP, TIMP, TNF-α and IL-6 levels in macrophages.

METHODS

Human primary monocyte-derived macrophages (n = 6 independent donors) were pretreated with 15-50 μg/mL PHT-Na+ or 15-50 μg/mL HPPH for 1 hour. Cells were then challenged with 100 ng/ml purified LPS from the periodontal pathogen, Aggregatibacter actinomycetemcomitans. Supernatants were collected after 24 hours and levels of MMP-1, MMP-2, MMP-3, MMP-9, MMP-12, TIMP-1, TIMP-2, TIMP-3, TIMP-4, TNF-α and IL-6 determined by multiplex analysis or enzyme-linked immunoadsorbent assay.

RESULTS

A dose-dependent inhibition of MMP-1, MMP-3, MMP-9, TIMP-1 but not MMP-2 was noted in culture supernatants pretreated with PHT or HPPH prior to LPS challenge. MMP-12, TIMP-2, TIMP-3 and TIMP-2 were not detected in culture supernatants. High concentrations of PHT but not HPPH, blunted LPS-induced TNF-α production although neither significantly affected IL-6 levels.

CONCLUSION

The ability of macrophages to mediate turnover of ECM via the production of metalloproteinases is compromised not only by PHT, but its metabolite, HPPH in a dose-dependent fashion. Further, the preferential dysregulation of macrophage-derived TNF-α but not IL-6 in response to bacterial challenge may provide an inflammatory environment facilitating collagen accumulation without the counteracting production of MMPs.

VEGF serum concentrations in patients with long bone fractures: a comparison between impaired and normal fracture healing

Vascular endothelial growth factor (VEGF) plays an important role in the bone repair process as a potent mediator of angiogenesis and it influences directly osteoblast differentiation. Inhibiting VEGF suppresses angiogenesis and callus mineralization in animals. However, no data exist so far on systemic expression of VEGF with regard to delayed or failed fracture healing in humans. One hundred fourteen patients with long bone fractures were included in the study. Serum samples were collected over a period of 6 months following a standardized time schedule. VEGF serum concentrations were measured. Patients were assigned to one of two groups according to their course of fracture healing. The first group contained 103 patients with physiological fracture healing. Eleven patients with delayed or nonunions formed the second group of the study. In addition, 33 healthy volunteers served as controls. An increase of VEGF serum concentration within the first 2 weeks after fracture in both groups with a following decrease within 6 months after trauma was observed. Serum VEGF concentrations in patients with impaired fracture healing were higher compared to the patients with physiological healing during the entire observation period. However, statistically significant differences were not observed at any time point between both groups. VEGF concentrations in both groups were significantly higher than those in controls. The present results show significantly elevated serum concentrations of VEGF in patients after fracture of long bones especially at the initial healing phase, indicating the importance of VEGF in the process of fracture healing in humans.

Effect of zwitterionic polymers on wound healing

The effect of a thin film of a zwitterionic random copolymer composed of carboxybetaine [1-carboxy-N,N-dimethyl-N-(2'-methacryloyloxyethyl)methanaminium inner salt] (CMB) and n-butyl methacrylate (BMA), poly(CMB-r-BMA) (CMB, 30 mol%), on the healing of a full-thickness excisional and incisional wound in hairless rats was examined. The poly(CMB-r-BMA) film significantly enhanced wound closure and complete healing of a full-thickness excisional wound compared with the effect of the poly(n-butyl methacrylate) (PBMA) and the poly(ethylene terephthalate) (PET) films. However, the poly(CMB-r-BMA) film did not enhance healing of a full-thickness incisional wound in hairless rats. The amount of proteins adsorbed and that of neutrophiles adhered onto the poly(CMB-r-BMA) film were significantly smaller than those onto the PBMA and PET films. The results suggested that various cells and growth factors in the wound exudate are utilized effectively by covering an excisional wound with the poly(CMB-r-BMA) film, resulting in acceleration of healing. In addition, the poly(CMB-r-BMA) film significantly enhanced healing of a full-thickness excisional wound in hairless rats compared with the effect of Tegaderm as wound dressings. The poly(CMB-r-BMA) film has potential as a new wound dressing.

Erk5 controls Slug expression and keratinocyte activation during wound healing

Reepithelialization during cutaneous wound healing involves numerous signals that result in basal keratinocyte activation, spreading, and migration, all linked to a loosening of cell-cell adhesion structures. The transcription factor Slug is required for this process, and EGF treatment of human keratinocytes induced activating phosphorylation of Erk5 that coincides with slug transcription. Accordingly, ectopic activation of Erk5 led to increased Slug mRNA levels and faster wound healing, whereas keratinocyte migration was totally blocked by Erk5 pathway inhibition. Expression of a shRNA specific for Erk5 strongly diminished Erk5 levels in keratinocytes and significantly decreased their motility response to EGF, along with induction of Slug expression. These Erk5-deprived keratinocytes showed an altered, more compact morphology, along with disruption of desmosome organization. Accordingly, they displayed an altered ability to form cell aggregates. These results implicate a novel EGFR/Erk5/Slug pathway in the control of cytoskeleton organization and cell motility in keratinocytes treated with EGF.

The usefulness of 111indium-oxine autologous platelet gel graft imaging to evaluate osteoinduction in patients undergoing surgery of jaw bone defects

Autologous platelet gel (AGP) is a source of concentrated growth factors contained in the platelet granules used to enhance bone quality and, especially, quicken bone formation in regeneration techniques, and also ameliorate the haemostasis in anti-coagulated patient management. The purpose of this study is to describe a technique to perform labelling of autologous platelet-gel with 111In -Oxine and to evaluate its usefulness, as a marker of bone osteoinduction by means of scintigraphy, after in vivo application in patients with jaw bone defects following cystic lesion enucleation and the extraction of deeply impacted lower third molar. All patients included in the study presented mandible bone defects following cyst enucleation or deeply impacted lower third molar extraction. In sterile conditions, 111In-Oxine AGP was added during the bone-milling phase of the graft preparation and then applied to the bone defects. The scintigraphy was performed 2 hours after the application of labelled AGP (early scan) and at 24, 48, 72, 384 hours (delayed scan). At early scan all the patients presented a high concentration of 111In-Oxine AGP, which was easily recognized at the level of jaw defect. Limited diffusion of AGP was seen in the tissue surrounding the bone defect; this activity was attributed to the presence, in the PRP, of a quote of autologous granulocytes, as marker of inflammatory process, which was labelled with 111In-Oxine. In order to demonstrate the persistence and stability of labelling AGP, abdominal scintigraphies were performed to assess the presence of activity in the liver, spleen and bone marrow. None of the patients presented appreciable activity in these organs. The labelled AGP topically applied showed high uptake values, without statistically significant activity in the surrounding tissues or in critical organs during the early phase, as well as in delayed controls, and confirmed a very low grade of loss of 111In-Oxine from the bone defect. The scintigraphy represents a useful method of assessing the success of surgical procedure for jaw bone defects performed with autogenous grafts. It is well accepted by the patients, offering at the same time a sensitive method of studying uptake of topically applied AGP and to follow up kinetics of AGP in order to correlate quantitative data of the platelet gel life span with evolution of the bone remodelling process. Finally, the labelled granulocytes around the bone defect allow to assess the inflammatory process evolution derived from the surgical technique.

Basic fibroblast growth factor treatment for various types of recalcitrant skin ulcers: reports of nine cases

The treatment of chronic intractable ulcers constitutes crucial topics in dermatological practice. We describe here nine cases of different types of therapy-resistant ulcers that were successfully treated with the employment of spraying with basic fibroblast growth factor once daily. When it was initiated, we could easily find in all the cases that the healing process of the ulcers was greatly accelerated by this therapy with the resultant achievement of complete epithelialization in a relatively short time. This therapeutic modality is useful not only for chronic ulcers but also for acute extensive ulcers.