Application of fibrin rich blocks with concentrated growth factors in pre-implant augmentation procedures

INTRODUCTION

Growth factors are mediators regulating the key processes of tissue regeneration, including cell proliferation and differentiation, extracellular matrix synthesis, chemotaxis and angiogenesis. In addition to the role they play in haemostasis and inflammatory processes, thrombocytes are of major importance in the reparation of mineralized and soft tissues. Application of fibrin rich blocks with concentrated growth factors is one of the latest approaches to guided bone regeneration and augmentation of lost bony structures of the alveolar ridge.

CASE REPORT

This paper presents a case of a female patient who underwent reconstruction of the defect of residual alveolar ridge of the upper jaw by applying fibrin rich blocks with concentrated growth factors and subsequent placement of two titanium endosteal implants five months after wound healing.

CONCLUSION

The loss of a single tooth or several teeth sometimes entails the augmentation of lost bony structures in order to provide optimal conditions for dental implant placement and subsequent prosthetic rehabilitation. A range of contemporary surgical procedures and a variety of dental materials for reconstruction of bony defects of the upper and lower jaws are available nowadays. The method described in this paper, i.e. the application of concentrated growth factors is one of the latest approaches which poses no risk of transmissible and allergic diseases and is at the same time cost effective.

An experimental double-blind irradiation study of a novel topical product (TPF 50) compared to other topical products with DNA repair enzymes, antioxidants, and growth factors with sunscreens: implications for preventing skin aging and cancer

The exposure to ultraviolet radiation (UVR) is a major risk factor for skin aging and the development of non-melanoma skin cancer (NMSC). Although traditional sunscreens remain the mainstay for the prevention of UVR-induced skin damage, they cannot ensure a complete protection against the whole spectrum of molecular lesions associated with UVR exposure. The formation of helix-distorting photoproducts such as cyclobutane pyrimidine dimers (CPD), as well as oxidative damage to DNA bases, including the formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8OHdG) are among the key DNA lesions associated with photoaging and tumorigenesis. Besides DNA lesions, UVR-induced formation of free radicals can result in protein carbonylation (PC), a major form of irreversible protein damage that inactivates their biological function. This study compares a complex novel topical product (TPF50) consisting of three actives, ie, 1) traditional physical sunscreens (SPF 50), 2) a liposome-encapsulated DNA repair enzymes complex (photolyase, endonuclease, and 8-oxoguanine glycosylase [OGG1]), and 3) a potent antioxidant complex (carnosine, arazine, ergothionine) to existing products. Specifically, we assessed the ability of TFP50 vs those of DNA repair and antioxidant and growth factor topical products used with SPF 50 sunscreens in preventing CPD, 8OHdG, and PC formation in human skin biopsies after experimental irradiations. In head-to-head comparison studies, TPF50 showed the best efficacy in reducing all of the three molecular markers. The results indicated that the three TPF50 components had a synergistic effect in reducing CPD and PC, but not 8OHdG. Taken together, our results indicate that TPF50 improves the genomic and proteomic integrity of skin cells after repeated exposure to UVR, ultimately reducing the risk of skin aging and NMSC.

Plasma rich in growth factors (PRGF-Endoret) reduces neuropathologic hallmarks and improves cognitive functions in an Alzheimer's disease mouse model

Impaired growth factor function is thought to drive many of the alterations observed in Alzheimer's disease (AD) patients. Endogenous regenerative technology, PRGF (plasma rich in growth factor)-Endoret, is designed for the delivery of a complex pool of patient's own active morphogens that may stimulate tissue regeneration. We obtained and characterized PRGF-Endoret preparations from human blood. We used, as experimental approach in vivo, APP/PS1 mice, characterized by age-dependent brain amyloid-β (Aβ) accumulation. Intranasal administration of PRGF-Endoret to APP/PS1 mice resulted in an important decrease in brain Aβ deposition and tau phosphorylation. PRGF-Endoret-treated APP/PS1 mice also showed decreased astrocyte reactivity, and prevented protein synaptic loss. In vitro approaches demonstrated that PRGF-Endoret treatment modulated astrocyte activation, reducing inflammatory responses, and promoted Aβ degradation. Furthermore, PRGF-Endoret stimulated global improvements in anxiety, learning, and memory behaviors. Our findings show that PRGF-Endoret exerts multifunctional and complementary effects that result in the reversal of the broad range of cognitive deficits in AD, suggesting that PRGF-Endoret may hold promise as an innovative therapy in AD.

Therapeutic protocol using growth factors in electrocution wounds--case reports and review of the literature

Injuries by high voltage electrocution represent rare and very complex accidents. In order to provide support to surgical therapy, to limit the extension of injuries or to support the natural process of tissue repair, we oriented towards the use of two growth factors, insulin and platelet-enriched plasma (PRP) administered locally, on the injury site. The therapeutic protocol was applied on three cases of electrocution with promising results in reducing the duration of surgical and pharmacological treatment and of time of hospitalization. The influence of growth factors on healing wounds, the mechanism of action and recent therapeutic applications are also discussed.

Efficacy of rhBMP-2 versus iliac crest bone graft for posterior C1-C2 fusion in patients older than 60 years

Few studies have specifically examined the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2)/absorbable collagen sponge (ACS) in posterolateral lumbar spine fusion. The purpose of this study was to report the clinical outcomes in elderly patients treated with posterior C1-C2 fusion with iliac crest bone graft (ICBG) plus rhBMP-2/ACS vs ICBG alone. One hundred forty patients older than 60 years were enrolled in this prospective, randomized trial and underwent instrumented C1- C2 fusion. Patients were divided into 2 groups based on fusion material. The ICBG group comprised patients who received ICBG alone, and the rhBMP-2/ACS group comprised patients who received ICBG plus rhBMP-2/ACS. The groups were compared based on operative time, estimated blood loss, hospital length of stay, clinical results, perioperative complications, fusion rate, fusion time, and revision rate. There were no significant differences in operative time, estimated blood loss, length of stay, and intraoperative complications between the 2 groups. Improvements in visual analog scale scores and Japanese Orthopaedic Association scores over the 2-year follow-up period were similar between groups. The fusion rate was 82.4% (56 of 68) in the rhBMP-2/ACS group and 78.7% (52 of 66) in the ICBG group (P=.782). Mean fusion time was 11 days shorter in the rhBMP-2/ACS group (81.8±29.4 days) than in the ICBG group (92.9±23.7 days) (P=.034). There were more wound complications requiring treatment in the rhBMP-2/ACS group (n=6; 8.8%) than in the ICBG group (n=2; 3.0%), although this was not statistically significant (P=.118). The use of rhBMP-2/ACS for posterior C1-C2 fusion appears to result in a relatively shorter fusion time, but there may be an increased risk of posterior cervical wound complications.

Apelin stimulates both cholecystokinin and glucagon-like peptide 1 secretions in vitro and in vivo in rodents

Apelin is an enteric peptide that exerts several digestive functions such as stimulation of cell proliferation and cholecystokinin (CCK) secretion. We investigated using murine enteroendocrine cell line (STC-1) and rats if apelin-13 stimulates both CCK and glucagon-like peptide 1 (GLP-1) secretions. We demonstrated that, in vitro and in vivo, apelin-13 increases the release of these two hormones in a dose-dependent manner. Present data suggest that apelin may modulate digestive functions, food intake behavior and glucose homoeostasis via apelin-induced release of enteric CCK but also through a new incretin-releasing activity on enteric GLP-1.

The effects of plasma rich in growth factors (PRGF-Endoret) on healing of medial collateral ligament of the knee

PURPOSE

Platelet-rich plasma (PRP) has been increasingly used in sports-related injuries for therapeutic applications. However, there are numerous manufacturing procedures and treatment protocols of PRP use, which make difficult to assess its real efficacy for tissue healing. This study addressed to evaluate the therapeutic effects of locally delivered plasma rich in growth factors (PRGF-Endoret) on the early healing of medial collateral ligament (MCL) in rabbit knees.

METHODS

Thirty-one Japanese white rabbits were subjected to a mop-end tear in the MCL of the left knee. PRGF-Endoret was prepared using Anitua's technique. Two groups were set up. In 17 knees, prepared 1.0 ml of PRGF-Endoret after clotting was applied on the tear site, while in 14 knees the tear site was untreated serving as a control. Quantitative aspects of PRGF-Endoret, the concentration of platelets, leukocytes and erythrocytes and therapeutic growth factors such as PDGF-BB and TGF-β1 were measured. Rabbits were sacrificed at 3 and 6 weeks after the operation and histological and biomechanical evaluation were performed.

RESULTS

No leukocytes were measured and certain amount of growth factors such as PDGF-BB and TGF-β1 were confirmed in the PRGF-Endoret. PRGF-Endoret stimulated proliferation of fibroblasts and neovascularization, and induced statistically better structural properties in repaired MCL.

CONCLUSIONS

Our findings provide evidence that local administration of PRGF-Endoret promotes early steps in ligament healing and the repair of structural properties in a rabbit model. PRGF-Endoret would be a useful product in clinical treatment of ligament injuries.

Tumor endothelial cell-specific drug delivery system using apelin-conjugated liposomes

Background

A drug delivery system specifically targeting endothelial cells (ECs) in tumors is required to prevent normal blood vessels from being damaged by angiogenesis inhibitors. The purpose of this study was to investigate whether apelin, a ligand for APJ expressed in ECs when angiogenesis is taking place, can be used for targeting drug delivery to ECs in tumors.

Methods and Results

Uptake of apelin via APJ stably expressed in NIH-3T3 cells was investigated using TAMRA (fluorescent probe)-conjugated apelin. Both long and short forms of apelin (apelin 36 and apelin 13) were taken up, the latter more effectively. To improve efficacy of apelin- liposome conjugates, we introduced cysteine, with its sulfhydryl group, to the C terminus of apelin 13, resulting in the generation of apelin 14. In turn, apelin 14 was conjugated to rhodamine-encapsulating liposomes and administered to tumor-bearing mice. In the tumor microenvironment, we confirmed that liposomes were incorporated into the cytoplasm of ECs. In contrast, apelin non-conjugated liposomes were rarely found in the cytoplasm of ECs. Moreover, non-specific uptake of apelin-conjugated liposomes was rarely detected in other normal organs.

Conclusions

ECs in normal organs express little APJ; however, upon hypoxic stimulation, such as in tumors, ECs start to express APJ. The present study suggests that apelin could represent a suitable tool to effectively deliver drugs specifically to ECs within tumors.

Heparin-binding epidermal growth factor-like growth factor protects rat intestine after portal triad clamping

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a potent mitogen and chemotactic factor. HB-EGF attenuates intestinal ischemia/reperfusion injury caused by superior mesenteric artery occlusion. We examined whether HB-EGF offers protection against intestinal congestion/reperfusion (C/R) injury, which is caused by portal triad clamping. Male Sprague-Dawley rats were randomly divided into three equally sized groups: I, sham-operated; II, portal triad clamping (Pringle maneuver); III, II + intraluminal administration of HB-EGF. Compared with sham-operated rats, all rats in group II exhibited significant increases in intestinal histologic injury, pro-inflammatory cytokine expression, myeloperoxidase activity, malonaldehyde levels, and apoptosis indices. Intraluminal administration of HB-EGF in group III significantly reduced these indicators when compared with group II. Clamping of the portal triad followed by reperfusion causes intestinal C/R injury and intraluminal administration of HB-EGF reduces the severity of intestinal C/R injury in rats.

The Effects of Filtrate of the Secretion of the Cryptomphalus Aspersa on Photoaged Skin

BACKGROUND

Growth factors (GFs) are chemical messengers that regulate specific cellular activities such as cell proliferation and formation of the extracellular matrix. GFs may be derived from a variety of sources, including animals.

OBJECTIVE

Evaluate the safety and efficacy of a topical antiphotoaging product containing secretions of the snail Cryptomphalus aspersa (SCA) for the improvement of facial rhytides.

MATERIALS AND METHODS

This was a 2-center, double-blind, randomized, 14-week study in which 25 patients with moderate to severe facial photodamage were treated with an emulsion (with 8% SCA) and liquid serum (with 40% SCA) on one side of the face and placebo on the contralateral side for 12 weeks. Silicone skin impressions of periocular rhytides were performed at baseline and after 12 weeks of treatment. Patient and physician assessments were also performed at 8, 12, and 14 weeks.

RESULTS

Periocular rhytides on the active ingredient side showed significant improvement after 12 weeks (P=.03) and improved texture to a greater degree than placebo at 8 and 12 weeks, as well as 2 weeks after discontinuing the product (14 weeks).

CONCLUSION

Daily application of topical products containing SCA proved effective and well tolerated for improvement in coarse periocular rhytides and fine facial rhytides. Subjects noted a significant degree of improvement in fines lines at the 8-week time point on the SCA-treated side (P≤.05) but did not report a significant difference in the quality of their skin.

Apelin retards the progression of diabetic nephropathy

Apelin and its receptor APJ have pleiotropic effects in mice and humans and play a protective role in cardiovascular diseases at least partially by inhibiting oxidative stress. Our objective was to study the effect of apelin on the progression of kidney disease in mice with established type 1 diabetes. Ove26 mice with type 1 diabetes received daily subcutaneous injections of apelin for 2 or 14 wk. APJ localizes in the glomeruli and blood vessels of kidneys. Renal APJ expression was reduced in diabetic mice but increased after treatment with apelin. Apelin treatment did not affect glycemia, body weight, or blood pressure in diabetic mice. Whole kidney and glomerular hypertrophy, as well as renal inflammation, including monocyte chemoattractant protein 1 and vascular cell adhesion molecule 1 expression, NF-κB activation, and monocyte infiltration, was inhibited after short and long treatment with apelin. Apelin administration significantly reduced albuminuria at 6 mo. Short treatment with apelin was sufficient to reverse the downregulation of the antioxidant enzyme catalase. Expression of angiotensin II and angiotensin type 1 receptor (AT1) in kidneys from diabetic mice treated was not affected by apelin. These findings show for the first time that apelin exerts a protective effect on the diabetic kidney. Short administration is sufficient to reduce kidney and glomerular hypertrophy as well as renal inflammation, but prolonged treatment is required to improve albuminuria. This effect was independent of the activation of the renin angiotensin system but correlated with upregulation of the antioxidant catalase. Apelin may represent a novel tool to treat diabetic nephropathy.

Study to evaluate the aesthetic clinical impact of an autologous antiaging serum

Since ancient times, humans have fought a still-unwinnable battle against aging and time. The possibility of processing our own blood in order to obtain certain precious substances for a particular purpose has opened the gates for the development of new treatments, indications, and techniques. In this study, we obtained an autologous serum with very high concentrations of some growth factors and anti-inflammatory cytokines using a special syringelike device that exposed the blood to medical-grade glass spheres in a closed system. The application of this autologous conditioned antiaging serum achieved local beauty enhancement results by improving skin hydration, smoothness, and elasticity.

[Modulation of low molecular weight heparin and heparin-binding epidermal growth factor on biological functions of human first trimester trophoblast]

OBJECTIVE

To evaluate the effects of low molecular weight heparin (LMWH) and heparin-binding epidermal growth factor (HB-EGF) on the biological function of human trophoblast in first trimester.

METHODS

From Feb. 2011 to Nov. 2011, the trophoblast isolated from human first trimester chorionic villi was cultured in vitro. Based on variation of LMWH concentration, the trophoblast was classified into 0.025 U/ml group, 0.25 U/ml group, 2.5 U/ml group, 25 U/ml group and 250 U/ml group. In the mean time, based on treatment of heparin, the trophoblast was classified into LMWH group (0.25 U/ml), HB-EGF group (10 µg/L), combination group (LMWH at 0.25 U/ml + HB-EGF at 10 µg/L) and add with DMEM as control group. Cell proliferation was assessed by the methyl thiazolyl tetrazolium (MTT) test, which was showed with the mean absorbance as A value. Cell invasion was measured by transwell, which counted the number of cells migrated to the superficies inferia of filter membrane. Cell differentiation was assessed by the concentration of hCG secretion.

RESULTS

Compared with control group, the trophoblast proliferation and invasion treated by LMWH at 0.025 U/ml did not show significant difference (P > 0.05). When treated by LWMH at 0.25 U/ml and 2.5 U/ml, trophoblast proliferation and invasion was increased significantly (P < 0.05). When LMWH at 25 U/ml and 250 U/ml, it could inhibit trophoblast proliferation and invasion (P < 0.05). When compared with A value of 0.44 ± 0.04 in control group, the increased A value were 0.51 ± 0.05 in LMWH group, 0.56 ± 0.04 in HB-EGF group and 0.69 ± 0.06 in combination group (P < 0.05). In the transwell test, the cell number were 511 ± 78 in LMWH group, 669 ± 67 in HB-EGF group and 872 ± 64 in combination group, which were significantly higher than 405 ± 67 in control group (P < 0.05), respectively. And the hCG concentration were (7143 ± 649) U/L in LMWH group, (11 762 ± 1059) U/L in HB-EGF group and (11 015 ± 1084) U/L in combination group, which showed statistical difference with (8182 ± 666) U/L in control group (P < 0.05).

CONCLUSION

LMWH could modulate trophoblast proliferation, invasion, and differentiation. HB-EGF is one of important factors involved in effects of LMWH on trophoblast function.

A critical review of modern and emerging absorbent dressings used to treat exuding wounds

Wound management has progressed significantly over the last five decades. This emanates from a greater understanding of wound healing, technological progression and improved clinical and scientific research. There are currently a plethora of absorbent dressings on the wound care market which claim to have the ability to manage exudates whilst encouraging healing. However, it is becoming clear, from analysing randomised controlled trials, that some of these absorbent dressings are not meeting their expectations when applied in a clinical setting. Many clinicians now feel that there should be more focus, not only on a dressing's ability to manage exudate efficiently, but on a dressing's ability to proactively encourage healing and thus exudate reduction will ensue. This paper proposes to critically review modern and emerging absorbent wound care dressings used to manage exuding wounds and discuses some advances in this area.

Recombinant acylation stimulating protein administration to C3-/- mice increases insulin resistance via adipocyte inflammatory mechanisms

Background

Complement 3 (C3), a key component of the innate immune system, is involved in early inflammatory responses. Acylation stimulating protein (ASP; aka C3adesArg), a C3 cleavage product, is produced in adipose tissue and stimulates lipid storage. We hypothesized that, depending on the diet, chronic ASP administration in C3^−/− mice would affect lipid metabolism and insulin sensitivity via an adaptive adipose tissue inflammatory response.

Methodology/Principal Findings

C3^−/− mice on normal low fat diet (ND) or high fat diet (HFD) were chronically administered recombinant ASP (rASP) for 25 days via an osmotic mini-pump. While there was no effect on food intake, there was a decrease in activity, with a relative increase in adipose tissue weight on ND, and a shift in adipocyte size distribution. While rASP administration to C3^−/− mice on a ND increased insulin sensitivity, on a HFD, rASP administration had the opposite effect. Specifically, rASP administration in C3^−/− HFD mice resulted in decreased gene expression of IRS1, GLUT4, SREBF1 and NFκB in muscle, and decreased C5L2 but increased JNK, CD36, CD11c, CCR2 and NFκB gene expression in adipose tissue as well as increased secretion of proinflammatory cytokines (Rantes, KC, MCP-1, IL-6 and G-CSF). In adipose tissue, although IRS1 and GLUT4 mRNA were unchanged, insulin response was reduced.

Conclusion

The effects of chronic rASP administration are tissue and diet specific, rASP administration enhances the HFD induced inflammatory response leading to an insulin-resistant state. These results suggest that, in humans, the increased plasma ASP associated with obesity and cardiovascular disease could be an additional factor directly contributing to development of metabolic syndrome, insulin resistance and diabetes.

In vivo, ex vivo, and in vitro studies on apelin's effect on myocardial glucose uptake

Apelin is an endogenous peptide hormone recently implicated in glucose homeostasis. However, whether apelin affects glucose uptake in myocardial tissue remains undetermined. In this study, we utilized in vivo, ex vivo and in vitro methods to study apelin's effect on myocardial glucose uptake. Pyroglutamated apelin-13 (2mg/kg/day) was administered to C57BL6/J mice for 7 days. In vivo myocardial glucose uptake was measured by FDG-PET scanning, and GLUT4 translocation was assessed by immunofluorescence imaging. For in vitro studies, differentiated H9C2 cardiomyoblasts were exposed to pyroglutamated apelin-13 (100 nM) for 2h. To test their involvement in apelin-stimulated myocardial glucose uptake, the energy sensing protein kinase AMPK were inhibited by pharmacologic inhibition (compound C) and RNA interference. IRS-1 phosphorylation was assessed by western blotting using an antibody directed against IRS-1 Ser-789-phosphorylated form. We found that apelin increased myocardial glucose uptake and GLUT4 membrane translocation in C57BL6/J mice. Apelin was also sufficient to increase glucose uptake in H9C2 cells. Apelin-mediated glucose uptake was significantly decreased by AMPK inhibition. Finally, apelin increased IRS-1 Ser-789 phosphorylation in an AMPK-dependent manner. The results of our study demonstrated that apelin increases myocardial glucose uptake through a pathway involving AMPK. Apelin also facilitates IRS-1 Ser-789 phosphorylation, suggesting a novel mechanism for its effects on glucose uptake.

Biomaterial delivery of morphogens to mimic the natural healing cascade in bone

Complications in treatment of large bone defects using bone grafting still remain. Our understanding of the endogenous bone regeneration cascade has inspired the exploration of a wide variety of growth factors (GFs) in an effort to mimic the natural signaling that controls bone healing. Biomaterial-based delivery of single exogenous GFs has shown therapeutic efficacy, and this likely relates to its ability to recruit and promote replication of cells involved in tissue development and the healing process. However, as the natural bone healing cascade involves the action of multiple factors, each acting in a specific spatiotemporal pattern, strategies aiming to mimic the critical aspects of this process will likely benefit from the usage of multiple therapeutic agents. This article reviews the current status of approaches to deliver single GFs, as well as ongoing efforts to develop sophisticated delivery platforms to deliver multiple lineage-directing morphogens (multiple GFs) during bone healing.

Supraspinal antinociceptive effect of apelin-13 in a mouse visceral pain model

Apelin, as the endogenous ligand of the APJ receptor, is a novel identified neuropeptide whose biological functions are not fully understood. APJ receptor mRNA was found in several brain regions related to descending control system of pain, such as amygdala, hypothalamus and dorsal raphe nucleus (DRN). The present study was designed to determine whether supraspinal apelin-13 may produce antinociceptive effect observed in the acetic acid-induced writhing test, a model of visceral pain. Apelin-13 not only significantly produced preemptive antinociception at the dose of 0.3, 0.5, 1 and 3 μg/mouse when injected intracerebroventricularly (i.c.v.) before acetic acid, but also significantly induced antinociception at a dose of 0.5, 1 and 3 μg/mouse when injected i.c.v. after acetic acid. And i.c.v. apelin-13 did not influence 30-min locomotor activity counts in mice. Intrathecal (i.t.) administration of apelin-13 (1 and 3 μg/mouse) significantly decreased the number of writhes, however, intraperitoneal (i.p.) injection of apelin-13 (10-100 μg/mouse) had no effect on the number of writhes in the writhing test. The specific APJ receptor antagonist apelin-13(F13A), no-specific opioid receptor antagonist naloxone and μ-opioid receptor antagonist β-funaltrexamine hydrochloride (β-FNA) could significantly antagonize the antinociceptive effect of i.c.v. apelin-13, suggesting APJ receptor and μ-opioid receptor are involved in this process. Central low dose of apelin-13 (0.3 μg/mouse, i.c.v.) could significantly potentiate the analgesic potencies of modest and even relatively ineffective doses of morphine administrated at supraspinal level. This enhanced antinociceptive effect was reversed by naloxone, suggesting that the potentiated analgesic response is mediated by opioid-responsive neurons.

Growth factor delivery: how surface interactions modulate release in vitro and in vivo

Biomaterial scaffolds have been extensively used to deliver growth factors to induce new bone formation. The pharmacokinetics of growth factor delivery has been a critical regulator of their clinical success. This review will focus on the surface interactions that control the non-covalent incorporation of growth factors into scaffolds and the mechanisms that control growth factor release from clinically relevant biomaterials. We will focus on the delivery of recombinant human bone morphogenetic protein-2 from materials currently used in the clinical practice, but also suggest how general mechanisms that control growth factor incorporation and release delineated with this growth factor could extend to other systems. A better understanding of the changing mechanisms that control growth factor release during the different stages of preclinical development could instruct the development of future scaffolds for currently untreatable injuries and diseases.

Strategies for controlled delivery of growth factors and cells for bone regeneration

The controlled delivery of growth factors and cells within biomaterial carriers can enhance and accelerate functional bone formation. The carrier system can be designed with pre-programmed release kinetics to deliver bioactive molecules in a localized, spatiotemporal manner most similar to the natural wound healing process. The carrier can also act as an extracellular matrix-mimicking substrate for promoting osteoprogenitor cellular infiltration and proliferation for integrative tissue repair. This review discusses the role of various regenerative factors involved in bone healing and their appropriate combinations with different delivery systems for augmenting bone regeneration. The general requirements of protein, cell and gene therapy are described, with elaboration on how the selection of materials, configurations and processing affects growth factor and cell delivery and regenerative efficacy in both in vitro and in vivo applications for bone tissue engineering.

Healing of laser-induced tympanic membrane perforations in rats: no contribution of granulocyte colony-stimulating factor or Gelfoam

OBJECTIVES

To study whether granulocyte colony-stimulating factor together with Gelfoam (absorbable gelatin sponge, USP) could enhance the healing of freshly perforated tympanic membranes. The frequency and occurrence of different immunocompetent cells and collagen types was noted.

METHODS

Laser perforations were made in the tympanic membrane of rats that were sacrificed at different time intervals post-myringotomy: Day 1, 3, 6, and 12. Tympanic membrane specimens were embedded and sections were stained with hematoxylin/eosin and an immunohistochemical technique was used, with antibodies against macrophages, B-cells, T-cells, and type I-IV collagens. Semi-quantification was performed after counting positive cells, mean values were calculated and analyzed statistically.

RESULTS

All perforations, except one, had closed by Day 12 and no difference was observed between experimental and control ears at the other time points. Gelfoam was still present in a high amount at Day 12. The sections were initially stained positive for type I and II collagen, but after Day 6, the regenerating tissue stained positive for mainly type III and IV collagens. Results showed that the recruitment of macrophages, B-cells, and T-cells could not be mapped with a statistical significance.

CONCLUSIONS

This study showed that at 6-12 days post-laser myringotomy, type III and IV collagen has replaced the collagen type II that normally constitutes the healthy tympanic membrane. There is a concern for excessive scarring involving adjacent structures. It was also seen that the combination of Gelfoam and granulocyte colony-stimulating factor or saline did not affect the healing times in perforated tympanic membranes. No significant results regarding the inflammatory cell recruitment could be obtained on the studied time points or between experimental and control ears, except for in the Gelfoam matrix.

Apelin is involved in postprandial responses and stimulates secretion of arginine-vasopressin, adrenocorticotropic hormone, and growth hormone in the ruminant

Apelin and its mRNA are expressed in several tissues, including the supraoptic and paraventricular nuclei in the hypothalamus. Although apelin is reported to be involved in the regulation of fluid homeostasis, little is known about the postprandial dynamics of apelin in plasma and its regulatory effects on the anterior pituitary hormones of ruminants. Therefore, the aims of this study were to investigate the following: (1) changes in plasma apelin concentrations in response to food intake under conditions of hydration (free access to water) or dehydration (water restriction), and (2) the effects of intravenous administration of apelin on plasma concentrations of arginine-vasopressin (AVP), ACTH, GH, and insulin. In Experiment 1 with the use of goats, the postprandial plasma apelin concentration was significantly increased under the dehydration condition compared with the hydration condition, and this increase was accompanied by increased plasma concentrations of AVP and ACTH after 24 h of dehydration. In Experiment 2 with the use of sheep and hydration conditions, the intravenous administration of apelin ([Pyr(1)]-apelin-13; 0.5 mg/head) caused a tendency to increase or caused a significant increase in plasma concentrations of AVP, ACTH, GH, insulin, and glucose. On the basis of these findings, we concluded that apelin is involved in the feeding process, and it regulates endocrine functions in the anterior pituitary gland via AVP in ruminant animals.

Treatment of through-and-through bone lesion using autologous growth factors and xenogeneic bone graft: a case report

BACKGROUND

This pilot case study aimed at evaluating the possibility of achieving optimal hard and soft tissue regeneration using plasma rich in growth factors (PRGF) and anorganic bovine bone (ABB) for the surgical treatment of a large through-and-through periapical bone lesion.

CASE REPORT

Maxillary incisors of a patient with through-and-through periapical lesion of endodontic origin were treated using modern endodontic surgical technique with the adjunct of PRGF. The PRGF clot was positioned over the palatal side of the lesion while the remaining bone defect was grafted with PRGF and ABB. A collagen membrane embedded with plasma very rich in growth factors covered the graft. Post-operative pain and swelling were negligible, and soft tissue healing was very fast. One-year clinical and radiographic outcome showed complete healing and functionality.

DISCUSSION

The addition of PRGF to ABB could improve the regenerative process, reducing postoperative symptoms and resulting in a fast and predictable hard and soft tissue healing.