Recombinant human epidermal growth factor (REGEN-D 150): effect on healing of diabetic foot ulcers

Recombinant human epidermal growth factor (REGEN-D 150), which was cloned and over expressed in E. coli, has shown enhanced healing of chronic diabetic foot ulcers (DFU) by significantly reducing the duration of healing in addition to providing excellent quality of wound healing and reepithelization. Post-marketing surveillance (PMS) study of REGEN-D 150 in 135 patients of DFU in India was compared with Phase III clinical trial data of REGEN-D 150 in India. Statistical analysis of study data determined that the empirical survival probability distribution, in terms of non-healing of ulcers, was lowest in the case of PMS study, better than that for Phase III; more DFU patients were healed in PMS study. Percentage of patients cured in any given week (e.g., in week 10) is above 90% in PMS study, as compared to 69% in Phase III clinical trial; this percentage was around 18% for the control group with placebo in the Phase III trial. The average wound healing time was significantly lower in PMS study, 4.8 weeks, while it was 9 weeks in Phase III clinical trials while the average wound healing with REGEN-D 150 was found to be 86% in this study. REGEN-D 150 has been found to result in healthy granulation and stimulate epithelization, thus leading to final wound closure. The PMS study has established the efficacy of REGEN-D 150 in faster healing of diabetic foot ulcers.

[Future treatment strategies for cryptorchidism to improve spermatogenesis]

Orchiopexy is one of the most frequently used surgical procedures for cryptorchidism and has been shown to have a beneficial effect on fertility. However, orchiopexy, especially for bilateral cryptorchidism, does not always guarantee subsequent fertility and paternity. Compared with a control group, paternity was significantly compromised in men with previous bilateral, but not unilateral cryptorchidism. Recent techniques of assisted reproductive technology, especially testicular sperm extraction with intracytoplasmic sperm injection (TESE-ICSI), have brought revolutionary changes in clinical therapy for infertiliy. If spermatozoa exists in testis of infertile men, logically there is a possibility of paternity. However, our study demonstrated that about 20% of pubertal boys who had had orchiopexy, were predicted to have lost their future paternity potential even if TESE-ICSI were conducted, because they were predicted to have no spermatozoa in the testis. To prevent or reverse the damage of spermatogenesis at prepuberty or puberty, we should not take a wait-and-see attitude but should consider a countermeasure for the pubertal boys who had had bilateral orchiopexy in childhood, especially when the serum follicle stimulating hormone level is elevated and testicular volume is lowered, before paternity is lost. In this review, we discuss the potential approaches including epidermal growth facter therapy, gene therapy and stem-cell therapy for cryptorchid patients in the future.

Expression of tumor necrosis factor-α and cyclooxygenase-2 mRNA in porcine split-thickness wounds treated with epidermal growth factor by quantitative real-time PCR

Epidermal growth factor (EGF) accelerates the re-epithelialization of damaged epidermal cell layers in a wound, so it especially shortens the duration of wound healing. The effect of EGF on pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha) and cyclooxygenase-2 (COX-2), levels during wound healing has not been reported. We investigated the relationship between exogenous EGF treatment and the expression of TNF-alpha and COX-2 mRNA in porcine split-thickness wounds by real-time PCR. Twenty split-thickness wounds were created on the back of five pigs. Fifteen wounds were treated twice daily with EGF ointments (1 microg/g, 10 microg/g, and 50 microg/g) for 10 days and five wounds were untreated. Healing time until full-epithelialization was evaluated. We performed a quantitative analysis of TNF-alpha and COX-2 mRNA expression in wound biopsies using real-time PCR. Topical application of 1 microg/g EGF accelerated re-epithelialization more than treatments of EGF at 10 microg/g and 50 microg/g, and no treatment. The levels of TNF-alpha and COX-2 mRNA were significantly greater in wounds treated with 1 microg/g than those with 10 microg/g and 50 microg/g EGF, and no treatment. Topical treatment of EGF influences the level of TNF-alpha and COX-2 mRNA within porcine split-thickness wounds. EGF-dependent slightly up-regulation of TNF-alpha and COX-2 mRNA expression during the inflammatory phase of healing may create an optimal molecular environment for wound healing.

Controlled-release of epidermal growth factor from cationized gelatin hydrogel enhances corneal epithelial wound healing

We designed a new ophthalmic drug-delivery system for epidermal growth factor (EGF) from the biodegradable hydrogel of cationized gelatin. We placed a cationized gelatin hydrogel (CGH) with incorporated (125)I-labelled EGF in the conjunctival sac of mice and measured the residual radioactivity at different times to evaluate the in vivo profile of EGF release. Approximately 60-67% and 10-12% of EGF applied initially remained 1 and 7 days after application, respectively; whereas EGF delivered in topically applied solution or via EGF impregnation of soft contact lenses disappeared within the first day. We also placed CGH films with 5.0 mug of incorporated EGF on round corneal defects in rabbits to evaluate the healing process using image analysis software and to assess epithelial proliferation immunohistochemically by counting the number of Ki67-positive cells. The application of a CGH film with incorporated EGF resulted in a reduction in the epithelial defect in rabbit corneas accompanied by significantly enhanced epithelial proliferation compared with the reduction seen after the topical application of EGF solution or the placement of an EGF-free CGH film. The controlled release of EGF from a CGH placed over a corneal epithelial defect accelerated ocular surface wound healing.

Accelerating effects of epidermal growth factor on skin lesions of pemphigus vulgaris: a double-blind, randomized, controlled trial

BACKGROUND

Pemphigus vulgaris (PV) is a severe blistering disease involving the skin and mucous membranes. The most common causes of death in these patients are adverse effects of drugs, and infection. Skin lesions are one of the important sources of infection. Thus, any local treatment that could reduce healing time of lesions and consequently reduce the total dosage of drugs needed to treat is favourable.

OBJECTIVE

To evaluate the efficacy of epidermal growth factor (EGF) in reducing healing time of lesions in patients with pemphigus vulgaris.

METHODS

In this randomized, double-blind, within-patient, left/right, controlled trial, 20 hospitalized patients with pathologial and immunohistologial (direct and indirect immunoflourecence) proven pemphigus vulgaris (PV) were chosen. In addition, all patients had at least one appropriate pemphigus lesion on each side of the body that had not healed after 2-week systemic therapy and sterile saline washing. EGF (10 microg/g) in 0.1% silver sulfadiazine cream vs. 0.1% silver sulfadiazine cream alone was applied randomly on one side of the body.

RESULTS

Kaplan-Meier survival analysis suggested that median time to heal with application of EGF plus silver sulfadiazine cream was 9 days, in comparison with 15 days for silver sulfadiazine cream alone (log-rank test, P=0.0003). No intervention-related adverse effect was observed during the study.

CONCLUSIONS

EGF can significantly reduce healing time of skin lesions in patients with pemphigus vulgaris, at least when this cream base is applied (Cochrane skin group identifier: CSG20).

Intestinal mucosa remodeling by recombinant human epidermal growth factor(1-48) in neonates with severe necrotizing enterocolitis

BACKGROUND AND AIMS

Neonatal necrotizing enterocolitis (NEC) is a common and serious acquired gastrointestinal tract condition. This clinical study assessed the potential clinical efficacy and microscopic effects of recombinant human epidermal growth factor 1-48 (EGF(1-48)) in neonates with NEC.

METHODS

This prospective, double-blind, randomized controlled study included 8 neonates with NEC. The study compared the effects of a 6-day continuous intravenous infusion of EGF(1-48) at 100 ng kg(-1) h(-1) against placebo. Clinical outcomes and morphological evaluation of serial rectal mucosal biopsies were assessed at baseline and 4, 7, and 14 days after starting EGF infusions.

RESULTS

There was no difference between the clinical safety outcomes recorded for EGF(1-48) or placebo patients. Quantitative morphologic differences in the rectal mucosa biopsies were noted with EGF(1-48) treatment compared with baseline or placebo and included a statistically significant increase in the number of mitoses per mucosal crypt on study day 4, significantly increased thickness of rectal mucosa from baseline on study days 4 and 7, and increased crypt surface area of rectal mucosa in parallel with increased mucosa thickness on day 14.

CONCLUSION

This study of EGF(1-48) in neonates with severe NEC showed that growth factor treatment was well tolerated and produced positive and measurable remodeling trophic effects on the gastrointestinal mucosa.

Effect of epidermal growth factor against radiotherapy-induced oral mucositis in rats

PURPOSE

We tested the efficacy of oral recombinant human epidermal growth factor (rhEGF) against radiation-induced oral mucositis in a rat model.

METHODS AND MATERIALS

Each of 35 Sprague-Dawley rats, 7 to 8 weeks of age and weighing 178 +/- 5 grams, was irradiated once in the head region with 25 Gy, using a 4-MV therapeutic linear accelerator at a rate of 2 Gy/min. The irradiated rats were randomly divided into four groups: those receiving no treatment (Group 1), those treated with vehicle only three times per day (Group 2), and those treated with 50 microg/mL (Group 3), or 100 microg/mL (Group 4) rhEGF three times per day.

RESULTS

Rats were monitored for survival rate and daily activity, including hair loss, sensitivity, and anorexia. We found that survival rate and oral intake were significantly increased and histologic changes were significantly decreased in the rhEGF-treated rats. There was no difference, however, between rats treated with 50 microg/mL or 100 microg/mL rhEGF.

CONCLUSION

These findings suggest that orally administered rhEGF decreased radiation-induced oral mucositis in rats.

Emodin, an anthraquinone derivative from Rheum officinale Baill, enhances cutaneous wound healing in rats

Emodin (1, 3, 8-trihydroxy-6-methyl-anthraquinone) is an anthraquinone derivative from the roots of Rheum officinale Baill, a Chinese herb widely and traditionally used for wound healing. Our objective was to determine whether topically applied emodin enhanced repair of rats' excisional wounds and its possible mechanism. Wounds were treated with either topical emodin (100, 200 and 400 microg/ml), recombinant human epidermal growth factor (rhEGF, 10 microg/ml), or vehicle for 7 or 14 days consecutively. At day 5 postinjury, wounds receiving emodin (400 microg/ml) were significantly smaller than those treated with vehicle. Emodin treatments had markedly more hydroxyproline content in day 7 wounds and tensile strength in day 14 wounds than that of vehicle control. The level of transforming growth factor- beta(1) (TGF-beta(1)) in wound tissues assessed by immunohistochemistry and reverse transcription polymerase chain reaction (RT-PCR), showed a dose-dependent increase in emodin-treated wounds compared with vehicle. Western immunoblotting analysis of wound tissues for Smad 2, 3, 4, 7 protein expression showed increase in Smad 2, 3 in the emodin-treated wounds compared with vehicle. In contrast, a reduction of Smad 7 was observed in emodin-treated wounds compared with vehicle and no change of Smad 4. In summary, our results showed that emodin promoted repair of rats' excisional wounds via a complex mechanism involving stimulation of tissue regeneration and regulating Smads-mediated TGF-beta(1) signaling pathway.

Primed fibroblasts and exogenous decorin: potential treatments for subacute vocal fold scar

OBJECTIVE

To investigate hepatocyte growth factor (HGF) primed fibroblasts and decorin application on skin and vocal fold fibroblasts in vitro and in vivo in rabbit vocal fold scar model.

STUDY DESIGN AND SETTING

Vocal fold and skin fibroblasts underwent five in vitro treatment conditions: control, epidermal growth factor, HGF, both decorin and HGF, and decorin alone. Hyaluronic acid and collagen enzyme-linked immunosorbent assays were performed. In vivo, 12 rabbits underwent unilateral vocal fold stripping. Injured vocal folds were then injected with skin fibroblasts, HGF, HGF-primed fibroblasts and decorin, or decorin. Outcomes included histologic and lamina propria height analyses.

RESULTS

In vitro, HGF increased hyaluronic acid synthesis in vocal fold fibroblasts (P<0.001). HGF and decorin treatment diminished collagen secretion (P<0.01). In vivo, histologic findings indicated minimal difference in collagen amount between treatment groups.

CONCLUSION

HGF and decorin together may decrease collagen production by skin and vocal fold fibroblasts. Fibroblast transplantation into scarred vocal folds has equivocal benefit.

Enhancing the effect of radionuclide tumor targeting, using lysosomotropic weak bases

PURPOSE

The aim of the present study was to investigate if treatment with lysosomotropic weak bases could increase the intracellular retention of radiohalogens and thereby increase the therapeutic effect of radionuclide tumor targeting.

METHODS AND MATERIALS

Four different lysosomotropic bases, chloroquine, ammonium chloride, amantadine, and thioridazine, were investigated for their ability to increase radiohalogen retention in vitro. The two most promising substances, chloroquine and ammonium chloride, were studied in several cell lines (A431, U343MGaCl2:6, SKOV-3, and SKBR-3) in combination with radiolabeled epidermal growth factor (EGF) or the HER2 binding affibody (Z(HER2:4))(2).

RESULTS

The uptake and retention of radionuclides was found to be substantially increased by simultaneous treatment with the lysosomotropic bases. The effect was, however, more pronounced in the epidermal growth factor:epidermal growth factor receptor (EGF:EGFR) system than in the (Z(HER2:4))(2):HER2 system. The therapeutic effect of ammonium chloride treatment combined with (211)At-EGF was also studied. The effect obtained after combined treatment was found to be much better than after (211)At-EGF treatment alone.

CONCLUSIONS

The encouraging results from the present study indicate that the use of lysosomotropic weak bases is a promising approach for increasing the therapeutic effect of radionuclide targeting with radiohalogens.

Healing of subacute tympanic membrane perforations in chinchillas treated with epidermal growth factor and pentoxifylline

HYPOTHESIS

The aims of the present study were to determine the effect of epidermal growth factor (EGF) and pentoxifylline on subacute tympanic membrane (TM) perforations and to quantify the healing rate of such perforations treated with these drugs alone or in combination.

BACKGROUND

It is known that EGF modulates in vitro and in vivo proliferation of epithelial and endothelial cells. Pentoxifylline is a methylxanthine that has been used to treat experimental skin flaps and venous leg ulcers. Data in the literature regarding this subject are contradictory, and quantitative data regarding the effects of EGF and pentoxifylline on TM perforation healing are scarce.

METHODS

We studied 50 chinchillas submitted to TM perforation. On postoperative Day 30, eight were selected for histologic analysis. Of the remaining 42, those presenting little or no healing were distributed into four groups: control, EGF, pentoxifylline, and EGF combined with pentoxifylline.

RESULTS

Histologic analysis showed that the observation period adopted was sufficient to consider the TM perforations subacute. We found significant differences between the study groups and the control group in the healing rate of subacute TM perforations during a 30-day period (analysis of variance; p < 0.001), which was 30.3% for the EGF group, 3.6% for the pentoxifylline group, 16.5% for the EGF-pentoxifylline group, and 8.7% for the control group.

CONCLUSIONS

The use of EGF promoted healing of subacute TM perforations in chinchillas, and the use of pentoxifylline did not. The combination of the two had no synergistic effect on the healing of these perforations.

[Changes in number of EGF positive neurons in ventral horn and contralateral cortex motor area of rhesus after hemisection spinal cord injury]

OBJECTIVE

To observe the changes in the amount of epidermal growth factor (EGF) immunopositive neurons in ventral horn and contralateral cortex motor area of rhesus following hemisection spinal cord injury (hSCI).

METHODS

Eighteen adult healthy rhesus were randomly divided into six groups: Sham-operation group; Day 7, Day 14, Month 1. Month 2 and Month 3 hemisection spinal cord injury groups. In the hSCI groups, the monkeys were subjected to left hemisection of T11 spinal cord, and then were put to death at the corresponding time after operation. The rostral part 5 mm proximal to the lesioned point of spinal cord and the caudal part 5 mm distal to the lesioned point were taken from each monkey. The contralateral cortex motor area was taken out, too. Frozen sections were incubated in specific polyclonal anti-EGF antibody; the immunohistochemical SP method was adopted in the study.

RESULTS

In 3 months after hSCI, the number of EGF immunopositive neurons in the ventral horn of spinal cord near the lesion and in the contralateral cortex motor area of brain decreased as compared with those of the sham-operation group (P<0.05). The number of positive neurons decreased first, then came back, and later after hSCI, decreased again (P<0.05). Besides this, the number of positive neurons varied in different parts at the same time point.

CONCLUSION

The EGF immunopositive neurons decreased apparently in the ventral horn of spinal cord near the lesion and in the contralateral cortex motor area in 3 months after hSCI. Hemisection spinal cord injury affected the expression of EGF for motor neurons in ventral horn on the lesioned side as well as on the intact side. Early after hSCI the number of positive neurons decreased sharply and then came back spontaneously in the ventral horn of spinal cord near the lesion and in the contralateral cortex of brain.

Role of growth factors on periodontal repair

Regeneration of periodontal structures lost during periodontal diseases constitutes a complex biological process regulated among others by interactions between cells and growth factors. Growth factors are biologically active polypeptides affecting the proliferation, chemotaxis and differentiation of cells from epithelium, bone and connective tissue. They express their action by binding to specific cell-surface receptors present on various target cells including osteoblasts, cementoblasts and periodontal ligament fibroblasts. The observation that growth factors participate in all cell functions led to exogenous application during periodontal tissue repair aiming to their use as an alternative therapeutic approach to periodontal therapy. Cell types and cultures conditions, dose, carrier materials, application requirements are of critical importance in the outcome of periodontal repair. The purpose of this article is to review the literature with respect to the biological actions of PDGF, TGF, FGF, IGF and EGF on periodontal cells and tissues, which are involved in periodontal regeneration.

The effect of various concentrations of human recombinant epidermal growth factor on split-thickness skin wounds

Epidermal growth factor (EGF) is a potent stimulant of epithelialisation. However, topical application of EGF to achieve facilitated re-epithelialisation in partial thickness wounds has been controversial. A total of 10 pigs, each with eight 4 x 4 cm partial thickness wounds, were treated twice a day for 10 days to observe the effect of human recombinant EGF in concentrations of 0.1, 1, 5, 10, 25 ug/g, vehicle only and two controls. The control and the vehicle-only wounds each demonstrated 100% healing time (HT100) of 9.31 +/- 1.34 and 8.5 +/- 1.12 while the wounds treated with EGF ointment with concentrations of 0.1 (HT100 = 6.4 +/- 0.71), 1 (HT100 = 5.2 +/- 0.63), 5 (HT100 = 5.8 +/- 0.85), 10 (HT100 = 7.1 +/- 1.45) and 25 ug/g (HT100 = 7.4 + 0.57) demonstrated significant reduction in time to achieve re-epithelialisation. Among the EGF-treated wounds, the wounds treated with EGF concentrations of 1 and 5 ug/g achieved the fastest re-epithelialisation with evidence of substantial increase in basal keratinocyte activity observed through Ki-67 activity. In conclusion, this article demonstrates the efficacy of human recombinant EGF in facilitating re-epithelialisation of partial thickness wounds with the most efficient healing found in EGF concentrations of 1 and 5 ug/g.

[Protective effect of epidermal growth factor on isograft mucosal structure after small bowel transplantation in rat]

OBJECTIVE

To investigate the effects of epidermal growth factor(EGF) on mucosal structure after small bowel transplantation in rat.

METHODS

Total small bowel transplantation was performed in inbred Wistar(RT1k) rats heterotopically, either total parenteral nutrition(control group, n=10) or TPN supplemented with epidermal growth factor(EGF group, n=10) was given to the recipients from the second day to 10th day after operation. The changes of morphology, ultrastructure, mucosal protein and DNA contents were determined.

RESULTS

The height of mucosal villus,the depth of crypt, the thickness of mucosa and the surface area of villus were (284.47+/-31.58)microm, (98.78+/-10.83 microm, (389.56+/-31.72)microm and (0.089+/-0.009 )mm(2) respectively in EGF group,and (176.45+/-14.62)microm, (74.45+/-8.34)microm, (259.38+/-24.65) microm, and (0.041+/-0.005)mm2 respectively in the control group. The morphological parameters were significantly higher in EGF group than those in the control group. Mucosal protein content was (84.65+/-8.32)mg/g wet wt in EGF group,significantly higher than (53.73+/- 11.45) mg/g wet wt in the control group(P=0.012). DNA content was also significantly higher in EGF group than that in the control group. [(0.86+/0.10)mg/g wet wt vs (0.51+/-0.06)mg/g wet wt, P=0.008]. Nearly normal ultrastructure of the graft enterocyte was maintained in EGF group, while atrophic microvilli and broken mitochondrial crista were observed in the control group.

CONCLUSION

EGF can preserve the mucosal structure of the graft, maintain the integrity of the ultrastructure of graft enterocyte after small bowel transplantation in rat.

Epidermal growth factor intralesional infiltrations can prevent amputation in patients with advanced diabetic foot wounds

This study examined if a series of epidermal growth factor (EGF) local infiltrations can enhance the healing process of complicated diabetic wounds. Twenty-nine in-hospital patients with diabetic neuropathic or ischaemic lesions with high risk of amputation were treated in a non controlled pilot study conducted at the National Institute of Angiology, Havana. Lesions, classified as Wagner's grade 3 or 4, included ulcers > or = 20 cm2 for > or = 25 days or amputation residual bases > or = 30 cm2 for > or = 15 days, healing refractory despite comprehensive wound care. EGF (25 microg) intralesional infiltrations (approximately 250 microl of a 25 microg/ml solution/injection point) were performed thrice weekly up to the eighth week. Wound closure was monitored during the treatment and recurrence examined for a year following discharge from hospital. Eighty-six per cent of the patients treated showed a productive granulation at infiltration session 8. Histological examination at this point indicated a substantial wound matrix transformation, granulation tissue cell repopulation and angiogenesis. Of the 29 patients treated, amputation was prevented in 17 (58.6%) of them who completed 24 infiltration sessions. They averaged 71.1 +/- 18.3% of reepithelisation during a mean in-hospital period of 66.5 +/- 4.9 days. Wound recurrence after 1 year of follow-up appeared in only one patient. Preliminary evidences suggest that EGF intralesional infiltrations may be effective in reducing diabetic lower limb amputation.

Recombinant human epidermal growth factor (EGF) to enhance healing for diabetic foot ulcers

This paper studies the healing effect of recombinant human epidermal growth factor (EGF) on chronic diabetic foot ulcers. A total of 89 patients (65 male and 24 female) aged from 36 to 82 years (average of 54) enrolled for the prospective, open-label trial, crossover study. Predetermined criteria were used for diagnosis and classification of ulcer. The average duration of ulcer was 6 months (range from 3 to 27 months) prior to study. Upon study, the ulcers were debrided and treated with hydrocolloid or composite dressing depending on the condition of the wound. If treatment effect was minimal using advanced dressing for 3 weeks, patients were crossed over to twice-a-day treatment with 0.005% EGF and advanced dressing. Among the patients, 21 patients showed improvement using hydrocolloid or composite dressing alone and 68 patients were crossed over to treatment with EGF and advanced dressing. In the EGF-treated patients, complete healing was noted in 52 patients within an average of 46 days (range from 2 to 14 weeks). Recurrence was not noted during the 6-month observation. But 5 patients showed new lesions different from the prior site. Sixteen patients required further interventions. This paper suggests that topical treatment with EGF combined with advanced dressing may have positive effects in promoting healing of chronic diabetic foot wounds.

Peptabody-EGF: A novel apoptosis inducer targeting ErbB1 receptor overexpressing cancer cells

The epidermal growth factor receptor (EGFR) plays a central role in cell life by controlling processes such as growth or proliferation. This receptor is commonly overexpressed in a number of epithelial malignancies and its upregulation is often associated with an aggressive phenotype of the tumor. Thus, targeting of EGFR represents a very promising challenge in oncology, and antibodies raised against this receptor have been investigated as potential antitumor agents. Various putative mechanisms of action were proposed for such antibodies, including decreased proliferation, induction of apoptosis, stimulation of the immunological response against targeted cancer cells or combinations thereof. We report here the development of an alternative high affinity molecule that is directed against EGFR. Production of this pentameric protein, named peptabody-EGF, includes expression in a bacterial expression system and subsequent refolding and multimerization of peptabody monomers. The protein complex contains 5 human EGF ligand domains, which confer specific binding towards the extracellular portion of EGFR. Receptor binding of the peptabody-EGF had a strong antiproliferative effect on different cancer cell lines overexpressing EGFR. However, cells expressing constitutive levels of the target receptor were barely affected. Peptabody-EGF treated cancer cells exhibited typical characteristics of apoptosis, which was found to be induced within 30 min after the addition of the peptabody-EGF. In vitro experiments demonstrated a significantly higher binding activity for peptabody-EGF than for the therapeutic monoclonal EGFR antibody Mab-425. Furthermore, the antitumor action provoked by the peptabody-EGF was greatly superior than antibody mediated effects when tested on EGFR overexpressing cancer cell lines. These findings suggest a potential application of this high affinity molecule as a novel tool for anti-EGFR therapy.

Preclinical pharmacokinetic, biodistribution, toxicology, and dosimetry studies of 111In-DTPA-human epidermal growth factor: an auger electron-emitting radiotherapeutic agent for epidermal growth factor receptor-positive breast cancer

Our objective was to evaluate the pharmacokinetics, normal tissue distribution, radiation dosimetry, and toxicology of human epidermal growth factor (hEGF) labeled with (111)In ((111)In-diethylenetriaminepentaacetic acid [DTPA]-hEGF) in mice and rabbits.

METHODS

(111)In-DTPA-hEGF (3.6 MBq; 1.3 or 13 microg) was administered intravenously to BALB/c mice. The blood concentration-time data were fitted to a 3-compartment model. Acute toxicity was studied with female BALB/c mice at 42 times the maximum planned human dose (MBq/kg) or with New Zealand White rabbits at 1 times the maximum planned human dose (MBq/kg) for a phase I clinical trial. Toxicity was evaluated by monitoring body weight, by determination of hematology and clinical biochemistry parameters, and by morphologic examination of tissues. Radiation dosimetry projections in humans were estimated on the basis of the residence times in mice by use of the OLINDA version 1.0 computer program.

RESULTS

The largest amounts of radioactivity were taken up by the liver (41.3 +/- 7.8 [mean +/- SD] percentage injected dose [%ID] at 1 h after injection and decreasing to 4.9 +/- 0.3 %ID at 72 h after injection) and kidneys (18.6 +/- 0.8 %ID at 1 h and decreasing to 4.5 +/- 0.2 %ID at 72 h after injection). (111)In-DTPA-hEGF was cleared rapidly from the blood, with a half-life at alpha-phase of 2.7-6.2 min and a half-life at beta-phase of 24.0-36.3 min. The half-life of the long terminal phase could not be accurately determined. The volume of distribution of the central compartment was 340-375 mL/kg, and the volume of distribution at steady state was 430-685 mL/kg. There was no significant difference in the ratio of body weight at 15 d to pretreatment weight for mice administered (111)In-DTPA-hEGF (1.02 +/- 0.01) and mice administered unlabeled DTPA-hEGF (1.01 +/- 0.01). Erythrocyte, leukocyte, and platelet counts and serum alanine aminotransferase and creatinine levels remained in the normal ranges. No morphologic changes were observed by light microscopy in any of 19 tissues sampled. Minor morphologic changes in the liver were observed by electron microscopy. The projected whole-body dose in humans was 0.19 mSv.MBq(-1). The projected doses to the liver, kidneys, and lower large intestine were 0.76, 1.82, and 1.12 mSv.MBq(-1), respectively.

CONCLUSION

(111)In-DTPA-hEGF was safely administered to mice and rabbits at multiples of the maximum dose planned for a phase I trial in breast cancer patients.

New growth factor therapies aimed at improving intestinal adaptation in short bowel syndrome

Short bowel syndrome (SBS) is used to describe a condition of malabsorption and malnutrition resulting from the loss of absorptive area following massive small bowel resection. The key to improved clinical outcome after massive small bowel resection is the ability of the residual bowel to adapt. Although still in experimental stages, a major goal in the management of SBS may be the augmented use of growth factors to promote increased adaptation. A number of growth factors have been implicated in promoting the adaptation process. The best-described growth factors are reviewed: glucagon-like peptide-2 (GLP-2), epidermal growth factor (EGF), and growth hormone (GH). This article reviews the ability of recombinant GLP-2, EGF and GH to modulate structural and functional aspects of intestinal adaptation following small bowel resection. Although these growth factors have shown promise, small sample size, inconsistent measurement parameters and uncontrolled study designs have hampered the acquisition of strong data advocating the use of growth factor treatment for SBS. Multicenter trials using well-defined outcome measures to assess clinical efficacy are needed to direct the clinical indications, timing and duration of therapy and assess potential risks associated with growth factor therapies.

An investigation on burn wound healing in rats with chitosan gel formulation containing epidermal growth factor

Various studies have shown that chitosan is effective in promoting wound healing. In this study, we aimed to develop an effective chitosan gel formulation containing epidermal growth factor (EGF), and to determine the effect on healing of second-degree burn wounds in rats. Ten micrograms per millilitre EGF in 2% chitosan gel was prepared. In an in vitro study to investigate release of EGF from the formulations, the release rate was 97.3% after 24 h. In in vivo studies, animals were divided into six groups as follows: silver sulfadiazine [Silverdin cream (SIL)], chitosan gel with and without EGF (EJ, J), EGF solution (ES) and untreated control groups [unburned (S) and untreated (Y) rats] applied groups, respectively. A uniform deep second-degree burn of the backskin was performed with water heated to 94+/-1 degrees C during a 15-s exposure. The EGF formulations were repeatedly applied on the burned areas with a dose of 0.160 microg/cm2 for 14 days (one application per day). Healing of the wounds was evaluated immunohistochemically, histochemically and histologically on the tissue samples. When the results were evaluated immunohistochemically, there were significant increases in cell proliferation observed in the EGF containing gel applied group (p<0.001). The histochemical results showed that the epithelization rate in the EJ group was the highest compared to the ES group results (p<0.001). The histological results indicated and supported these findings. It can be concluded that a better and faster epithelization was observed in the EJ group compared to the other groups.