[177Lu]Bz-DTPA-EGF: Preclinical Characterization of a Potential Radionuclide Targeting Agent Against Glioma

Patients with glioblastoma multiforme have a poor prognosis due to recurrences originating from spread cells. The use of radionuclide targeting might increase the chance of inactivating single tumor cells with minimal damage to surrounding healthy tissue. As a target, overexpressed epidermal growth factor receptors (EGFR) may be used. A natural ligand to EGFR, the epidermal growth factor (EGF) is an attractive targeting agent due to its low molecular weight (6 kDa) and high affinity for EGFR. 177Lu (T(1/2) = 6.7 days) is a radionuclide well suited for treatment of small tumor cell clusters, since it emits relatively low-energy beta particles. The goal of this study was to prepare and preclinically evaluate both in vitro and in vivo the [177Lu]Bz-DTPA-EGF conjugate. The conjugate was characterized in vitro for its cell-binding properties, and in vivo for its pharmacokinetics and ability to target EGFR. [177Lu]Bz-DTPA-EGF bound to cultured U343 glioblastoma cells with an affinity of 1.9 nM. Interaction with EGFR led to rapid internalization, and more than 70% of the cell-associated radioactivity was internalized after 30 minutes of incubation. The retention of radioactivity was good, with more than 65% of the 177Lu still cell-associated after 2 days. Biodistribution studies of i.v. injected [177Lu]Bz-DTPA-EGF in NMRI mice demonstrated a rapid blood clearance. Most of the radioactivity was found in the liver and kidneys. The liver uptake was receptor-mediated, since it could be significantly reduced by preinjection of unlabeled EGF. In conclusion, [177Lu]Bz-DTPA-EGF seems to be a promising candidate for locoregional treatment of glioblastoma due to its high binding affinity, low molecular weight, and ability to target EGFR in vivo.

A kit formulated under good manufacturing practices for labeling human epidermal growth factor with 111In for radiotherapeutic applications

Our goal was to design and manufacture a kit under good manufacturing practices (GMP) for the preparation of (111)In-DTPA-hEGF Injection, a novel targeted radiotherapeutic agent for advanced epidermal growth factor receptor (EGFR)-positive breast cancer.

METHODS

Human EGF (hEGF) was derivatized with diethylenetriaminepentaacetic acid (DTPA) and then purified by size-exclusion chromatography and ultrafiltration. Kits were prepared by dispensing 0.25 mg (1 mL) of DTPA-hEGF in 1 mol/L sodium acetate buffer [pH 6.0] into single-dose glass vials. Raw materials were pharmacopoieal or reagent grade according to the American Chemical Society and were tested for identity and purity. Kits were tested for protein concentration, purity and homogeneity (sodium dodecyl sulfate polyacrylamide gel electrophoresis and size-exclusion high-performance liquid chromatography), pH, clarity and color, volume, DTPA substitution, labeling efficiency, receptor binding to MDA-MB-468 human breast cancer cells, and sterility and apyrogenicity. (111)In-DTPA-hEGF Injection was tested for pH, radionuclidic and radiochemical purity, clarity and color, and sterility and apyrogenicity.

RESULTS

Four lots of kits and 8 lots of (111)In-DTPA-hEGF Injection passed all quality specifications. The labeling efficiency was 94%-99% with 115-773 MBq (111)In chloride added to a single kit. (111)In-DTPA-hEGF exhibited preserved receptor binding against MDA-MB-468 cells (affinity constant [K(a)], 0.9-1.1 x 10(7) L/mol; maximum number of binding sites per cell [B(max)], 1.1-2.2 x 10(6) sites per cell). In addition, labeling of aliquots of the kit suggested that a single vial could be labeled with up to 3,083 MBq (111)In while maintaining a radiochemical purity of >90%. Kits were stable for >90 d and (111)In-DTPA-hEGF Injection was stable for >24 h stored at 4 degrees C.

CONCLUSION

The kit formulation is suitable for preparing (111)In-DTPA-hEGF Injection for a phase I clinical trial in patients with advanced EGFR-positive breast cancer. Establishment of the GMP processes for (111)In-DTPA-hEGF Injection provides a useful example of manufacturing biotechnology-based investigational radiopharmaceuticals in an academic environment for early phase I clinical trials.

[An early comprehensive prevention and treatment of sepsis in severely burned patients with delayed fluid resuscitation]

OBJECTIVE

To study an early comprehensive prevention and treatment of sepsis in severely burned patients with delayed fluid resuscitation.

METHODS

From January 1990 to December 2001, 72 cases of patients with delayed fluid resuscitation were admitted to our burn department. Two different periods were divided and analyzed retrospectively. The first period was from January 1990 to December 2001 and the span of the second period was from January 1995 to December 2001.

RESULTS

(1)The mortality rate and incidence of sepsis in the second period (6.5 percent and 17.4 percent) were significantly lower than those of the first period (23.0 percent and 57.7 percent, P<0.05 and P<0.01). (2)The time of wound healing in the second period was (1.9+/-0.9) hours, it was lower than that of the first period (6.6+/-2.5) hours. (3)The serum contents of tumor necrosis factor (TNF) and blood lactic acid (BLA) were increased at all times in two periods and were markedly increased in the first period (all P<0.01).

CONCLUSION

Our data demonstrated that measures adopted in the second period for patients with delayed fluid resuscitation, including early excision, early rapid adequate resuscitation, early enteral feeding, increased immunity function, early applying antibactials, xenotransfusion of ultraviolet-irradiated blood, application of recombinant human-growth factor (rh-GH), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), are beneficial to the prevention and treatment of sepsis in severely burned patients with delayed fluid resuscitation.

Sustained local application of low-dose epidermal growth factor on steroid-inhibited colonic wound healing

BACKGROUND/PURPOSE

The effects of locally administered low-dose epidermal growth factor in a steroid-inhibited wound healing were investigated in a rat model.

METHODS

Long-acting release of epidermal growth factor was enabled using microspheres embedded in gelatin sponge. Study groups consisted of 60 rats with 10 in each: colonic anastomosis only (C), plus pure gelatin sponge (CG), plus epidermal growth factor loaded sponge (CE), colonic anastomosis and steroid (S), plus gelatine sponge (SG), and plus epidermal growth factor-loaded gelatine sponge (SE) groups. Bursting pressure and wound hydroxy-proline content were measured. Bursting sites were recorded. Collagen deposits, inflammation, and foreign body reactions were evaluated.

RESULTS

Bursting pressure and hydroxy-proline contents were found lowest in the S and highest in the CE groups (P <.01). There was almost no difference between C and SE groups. Bursts were encountered in peri-anastomotic normal colon sites in the nonsteroid-treated C, CG, and CE groups. They were noted overwhelmingly at the anastomosis in steroid-inhibited S, SG, and SE groups. Histopathology results showed a standstill at the inflammatory phase of healing in S and SG groups. The best healing was observed in the CE group. Degree of collagen accumulation was well correlated with bursting pressure and hydroxy-proline content data with a negligible foreign body reaction to gelatine sponge.

CONCLUSIONS

Continuous local epidermal growth factor administration by microspheres in gelatin increases wound collagen and further enhances healing in colonic anastomoses even with steroid inhibition.

Post-ischemic administration of heparin-binding epidermal growth factor-like growth factor (HB-EGF) reduces infarct size and modifies neurogenesis after focal cerebral ischemia in the rat

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a hypoxia-inducible, neuroprotective protein that also stimulates proliferation of neuronal precursor cells. Accordingly, HB-EGF may contribute to recovery from cerebral injury through direct neuroprotective effects, by enhancing neurogenesis, or both. When administered by the intracerebroventricular route 1-3 days after focal cerebral ischemia in adult rats, HB-EGF decreased the volume of the resulting infarcts and reduced post-ischemic neurological deficits. HB-EGF also increased the incorporation of bromodeoxyuridine into cells expressing the immature neuronal marker protein TUC-4 in the dentate subgranular and rostral subventricular zones, consistent with increased proliferation of neuronal precursors. However, HB-EGF decreased the number of newborn neurons that migrated into the ischemic striatum, perhaps partly because reduction of infarct size by HB-EGF also reduced the stimulus to migration. To determine if HB-EGF might also directly inhibit migration of neuronal precursors, we co-cultured subventricular zone (SVZ) explants treated with HB-EGF or vehicle together with hypoxic cerebral cortical explants, and measured cell migration from the former toward the latter. HB-EGF reduced directed migration of SVZ cells toward the cortical explants, possibly due to a local chemoattractant effect on neuronal precursor cells, which may be mediated through the HB-EGF-specific receptor, N-arginine dibasic convertase. The delayed neuroprotective effect of HB-EGF may have implications for efforts to prolong the therapeutic window for intervention in stroke.

Epidermal growth factor and necrotizing enterocolitis

As the number of extremely low-birth-weight infants increases,necrotizing enterocolitis remains a critical eminent problem. Supplementation of enteral feeds with biologically active substances normally present in breast milk, such as epidermal growth factor, seems to be a logical and safe way to reduce the incidence of intestinal inflammation and necrotizing enterocolitis. Continuing basic research and clinical studies are essential before epidermal growth factor can be introduced as an efficient therapeutic approach in the treatment of neonatal necrotizing enterocolitis.

Medical management of ulcerative colitis

Patients with ulcerative colitis have no increased mortality compared to population controls and the disease can be cured be colectomy. This review concentrates on the medical management of ulcerative colitis including the management of active colitis, acute severe colitis and first presentation of colitis, maintenance of remission and long-term complications.

Combined gastrin and epidermal growth factor treatment induces islet regeneration and restores normoglycaemia in C57Bl6/J mice treated with alloxan

AIMS/HYPOTHESIS

Increasing beta-cell mass and/or function could restore glucose homeostasis in diabetes mellitus. Hitherto, trophic factors for beta-cell regeneration after toxic events have been difficult to identify. We evaluated the application of gastrin and epidermal growth factor after alloxan-induced pancreatic beta-cell damage.

METHODS

After alloxan treatment (70 mg/kg), mice were implanted with Alzet osmotic minipumps releasing gastrin and epidermal growth factor for one week. We monitored glycaemia, did histological analyses of the pancreata and quantified pancreatic beta-cell mass and insulin content.

RESULTS

Alloxan treatment alone resulted in a persisting hyperglycaemic state. Combined gastrin and epidermal growth factor treatment restored normoglycaemia in 3 days, an effect which seemed permanent. Glucose tolerance tests showed normal glucose responsiveness. Gastrin on its own and epidermal growth factor on its own did not alleviate hyperglycaemia. Islet mass, islet density and pancreatic insulin content were higher in mice treated with gastrin and epidermal growth factor than in untreated mice with persisting hyperglycaemia. In normoglycaemic control mice treatment with gastrin and epidermal growth factor did not affect these parameters. We detected transitional cytokeratin-positive ductal to endocrine insulin-expressing cells and noted increased ductal but not beta-cell proliferation.

CONCLUSIONS/INTERPRETATION

Our results show that combined treatment with gastrin and epidermal growth factor can induce sufficient regeneration of a functional islet mass to restore glucose homeostasis.

Combination fusion protein therapy of refractory brain tumors: demonstration of efficacy in cell culture

Primary brain tumors including anaplastic astrocytomas and glioblastoma multiforme are difficult to treat because of their locally invasive nature and relative resistance to chemotherapy and radiation therapy. Novel agents that can kill multi-drug resistant tumor cells and reach tumor cells at distant sites in the brain are needed. One such class of agents is fusion proteins which consist of brain-tumor-selective peptide ligands fused to peptide toxins. The ligand directs the protein to the glioma cell surface; the peptide toxin is then internalized into the cell, translocates to the cytosol and catalytically inactivates protein synthesis leading to cell death. Fusion proteins are toxic to multi-drug resistant brain tumor cells. Because of the large molecular weight of these molecules, a unique delivery system has been developed--convection-enhanced delivery (CED). The method creates a bulk flow which supplements diffusion and achieves drug concentrations in the brain parenchyma orders of magnitude greater than by systemic administration. Patients with recurrent glioma treated with individual fusion protein CED have obtained clinical remissions lasting years. However, toxicities to normal brain have been observed and relapses ultimately occurred. To address the clinical need of these patients and improve upon the therapeutic index observed to date with single fusion protein CED, we generated a novel fusion protein DAB389EGF and tested it in combination with another active fusion protein, IL13PE38QQR. We observed potent glioma cytotoxicity with each fusion protein and synergistic toxicity with the combination. Further, brain tumor cells showed heterogeneous expression of individual receptors suggesting that the combination--DAB389EGF and IL13PE38QQR may show improved efficacy and should undergo further preclinical development for therapy of patients with relapsed high-grade gliomas.

Effect of epidermal growth factor on pulmonary hypoplasia in experimental diaphragmatic hernia

BACKGROUND/PURPOSE

Currently, tracheal occlusion (TO) is a potent stimulus for fetal lung growth but also a rather invasive and high-risk procedure. The aim of this study was to investigate a new and much less invasive therapeutic strategy, namely the maternal intraperitoneal administration of epidermal growth factor (EGF) and its effect on pulmonary hypoplasia in the nitrofen-induced congenital diaphragmatic hernia (CDH) rat model, especially its effect on type II pneumocytes.

METHODS

CDH was induced by maternal administration of a single oral dose (100 mg) of nitrofen on day 8.5 of pregnancy. Four groups of pregnant rats were designed on day 18.5: normal control (n = 4), CDH (n = 4), CDH plus Dex (n = 4), CDH plus EGF (n = 8). All fetuses were delivered by cesarean section on day 21. Accordingly, there were 4 groups of fetuses: normal controls (n = 33), nitrofen-induced CDH (n = 19), CDH plus Dex treatment (n = 15), and CDH plus EGF treatment (n = 24). Lung tissue weight (LW) and body weight (BW) of each fetus were recorded, lung histologic and morphometric evaluations were performed, and image analysis was combined after lung processing. Transmission electron microscopy was used for ultrastructural observation, especially type II pneumocytes.

RESULTS

CDH was observed in 58 of the 94 rat fetuses (61.7%). Lw/Bw of CDH group was significantly lower than those of Dex and EGF (P <.05). The lungs of CDH fetuses showed marked hypoplasia, in contrast to improved mesenchymal differentiation in that of Dex and EGF fetuses. Statistical differences of these morphologic parameters (RAC, MTBD, interstitial%, and alveoli%) were found (P <.05). As to ultrastructural features, type II cells of CDH lungs had few if any lamellar bodies and cytoplasmic organelles, and showed evidence of abundant glycogen granules. The sparse type II cells also showed cytoplasmic degenerative changes. By contrast, type II cells of EGF lungs showed numerous mitochondria, abundant lamellar bodies (surfactant) and deficiency of glycogen granules, and displayed prominent microvillous projections and pitlike depressions. The density of type II pneumocyte were 65 +/- 4.5, 31 +/- 3.1, and 8 +/- 1.5 for EGF, Dex, and CDH, respectively (EGF v Dex, P <.05; EGF v CDH, P < 0.01).

CONCLUSIONS

Compared with TO, prenatal EGF administration as a much less-invasive therapeutic strategy had shown marked improvement in pulmonary hypoplasia and promotion of type II pneumocyte differentiation in the nitrofen-induced CDH rat model. Thus, EGF could improve the prognosis of CDH by means of promoting pulmonary hypoplasia and improving the surfactant deficiency, which suggested a potential role in the clinical treatment of CDH.

[The study of peptide effect in the mechanisms of angiogenesis and forming of microenvironment of the tumors in old rats]

The experiments were performed in rats with transplanted sarkoma M-1. The injections of synthetic peptide vilon at the doses 0.5 mcg sigificantly increased the apoptosis of tumor cells in the experiment as compared to the control group. So vilon has possessed the oncomodulating action on the transplanted carcinoma. The injections of epigene lead to the inhibition of the sarcoma growth due to the development of the hemorragic necrosis and apoptosis increased. The results obtained suggested that vilon and epigene are the perspective preparates in the cancer therapy.

Growth factors: the wound healing therapy of the future

'Growth factors' is an umbrella term used to describe a variety of chemical messengers found in a wide range of tissues, which have a number of functions including the regulation of cell and tissue growth and development. Several growth factors have been proposed as ideal agents to promote wound healing. This review discusses their functions and how they can be applied in the management of chronic wounds.

Combined effect of gefitinib ('Iressa', ZD1839) and targeted radiotherapy with 211At-EGF

The EGFR-TKI (epidermal growth factor receptor tyrosine kinase inhibitor) gefitinib ['Iressa' (trademark of the AstraZeneca group of companies), ZD1839] increases the cellular uptake of radiolabelled epidermal growth factor (EGF). We investigated gefitinib treatment combined with astatine-211 EGF targeting in vitro using two cell lines expressing high levels of EGFR: A431 (sensitive to gefitinib) and U343MGaCl2:1 (resistant to gefitinib). In both cell lines, the uptake of 211At-EGF was markedly increased by concomitant treatment with gefitinib. Survival was investigated using both a clonogenic survival assay and a cell growth assay. Combined gefitinib and 211At-EGF treatment reduced the survival of U343 cells 3.5-fold compared with 211At-EGF alone. In A431 cells, 211At-EGF treatment resulted in very low survival, but combined treatment with gefitinib increased the survival by about 20-fold. These results indicate that combined treatment with gefitinib might increase the effect of ligand-mediated radionuclide therapy in gefitinib-resistant tumours and decrease the effect of such therapy in gefitinib-sensitive tumours.

Buccal mucosal ulcer healing effect of rhEGF/Eudispert hv hydrogel

We have studied the effect of rhEGF on the buccal mucosal ulcer healing. rhEGF was rapidly degraded upon incubation with the hamster buccal mucosal homogenates; The degradation of rhEGF was significantly inhibited by sodium lauryl sulfate (SLS). Eudispert hv hydrogel and Polycarbophil 974P hydrogel were prepared for rhEGF delivery and their mucoadhesiveness was measured by the Instron method. The mucoadhesive force of Eudispert hv was significantly greater than that of Polycarbophil 974P. Moreover, rhEGF in Eudispert hv hydrogel remained stable for about 2 months. To evaluate the ulcer healing effect of rhEGF, the buccal mucosal ulcer was induced in golden hamsters using acetic acid. At 24 h after administration of rhEGF/Eudispert hv hydrogel, the ulcerous area was decreased compared with rhEGF solution and, as a result, the curative ratio was 36.8 +/- 5.68%. By the addition of SLS (0.5%) to Eudispert hv hydrogel, the curative ratio increased 1.5 times. The mechanism of the action was probably due to a combination of protection of the drug against proteases present in mucosa and prolongation of the release of rhEGF from the formulation at the site of action.

Difference in responsiveness of human esophageal squamous cell carcinoma lines to epidermal growth factor for MMP-7 expression

Expression of MMP-7 in human esophageal squamous cell carcinoma lines (TE-9 and -10) was investigated. Under normal culture conditions, immunocytochemical staining and enzymography demonstrated the production of MMP-7 in their cytoplasm and its gelatinolytic activity in the medium of TE-9 and -10 cell cultures. When EGF was added to the cultures, Western blotting and RT-PCR analysis showed a dose-dependent increase in the amount of MMP-7 synthesized in the TE-9 cells, whereas in TE-10 cells, EGF failed to stimulate MMP-7 production. For luciferase reporter analysis of MMP-7 transcription, pMMP7LucWI (1132-bp) and pMMP7LucWII (334-bp) were cloned in the luciferase pGL3-basic vector. The promoter activity was enhanced from 1.5- to 2-fold by the addition of EGF to TE-9 cells transfected with pMMP7LucWI or WII, even though the response was low as compared with that of 12-O-tetra-decanoyl-phorbol-13-acetate (TPA); and in TE-10 cells, only TPA enhanced the promoter activity of MMP-7. Luciferase promoter analysis using a pMMP7WII mutant series revealed that the AP-1 site was essential for transcription of the MMP-7 gene in TE-9 cells, and Tcf-I was also an important site, and that to a lesser degree, Tcf-II and PEA3s participated in the transcription of the MMP-7 gene in these cells. Unlike the results with TE-9 cells, in TE-10 cells, EGF failed to stimulate transcription of the MMP-7 gene; and up-regulation of the promoter activity by TPA was dependent on the AP-1 site and to lesser degree, on Tcf-I and Tcf-II. These results suggest that EGF plays also an important role in MMP-7 production of TE-9 cells and that there is a difference not only in EGF-intracellular signaling system but also in regulation mechanisms of MMP-7 transcription by beta-catenin-Tcf and/or PEA3 system between these 2 carcinoma lines.

Epidermal growth factor enemas with oral mesalamine for mild-to-moderate left-sided ulcerative colitis or proctitis

BACKGROUND

Epidermal growth factor (EGF) is a potent mitogenic peptide produced by salivary glands. We examined whether EGF enemas are an effective treatment for active left-sided ulcerative colitis and ulceration limited to the rectum (proctitis).

METHODS

In a randomized, double-blind clinical trial conducted at Leicester Royal Infirmary, 12 patients with mild-to-moderate left-sided ulcerative colitis received daily enemas of 5 microg of EGF in 100 ml of an inert carrier and 12 received daily enemas with carrier alone for 14 days. All also began to receive 1.2 g of oral mesalamine per day or had their dose increased by 1.2 g per day. Patients were assessed clinically at 0, 2, 4, and 12 weeks and by sigmoidoscopy and biopsy at 0, 2, and 4 weeks. The primary end point was disease remission (defined by a St. Marks score of 4 or less without sigmoidoscopic evidence of inflammation) at two weeks. Secondary end points were clinically significant improvements in disease activity (defined by a decrease of more than 3 points in the St. Marks score or the ulcerative colitis disease-activity index) at two and four weeks. Analyses were performed according to the intention-to-treat principle.

RESULTS

After two weeks, 10 of the 12 patients given EGF enemas were in remission, as compared with 1 of 12 in the control group (83 percent vs. 8 percent, P<0.001). At the 2-week assessment, disease-activity scores, sigmoidoscopic score, and histologic scores were all significantly better in the EGF group than in the placebo group (P<0.01 for all comparisons), and this benefit was maintained at 4 weeks and at 12 weeks.

CONCLUSIONS

This study provides preliminary data suggesting that EGF enemas are an effective treatment for active left-sided ulcerative colitis.

[A comparative study on burn wound healing treated by different methods of recombinant human epidermal growth factor]

OBJECTIVE

To explore an optimal method of recombinant human epidermal growth factor(rhEGF) application on the burn wounds of superficial II degree and profound II degree for accelerating its healing.

METHODS

There were 180 burn wounds in 60 patients with the self-corresponding wound of the same degree as controls. The wounds of all patients were divided three regions(A, B, C). The wounds were treated once a day with 1% SD-Ag in region A as controls, with rhEGF(40 U/cm2) in region B, and with a combination of rhEGF(40 U/cm2) and Su Yu Ping (5 g) in region C. The wound healing time was recorded and compared.

RESULTS

In regions A, B and C, the healing time of superficial II degree wound was (13.20 +/- 2.40) days, (10.20 +/- 2.20) days and (8.72 +/- 2.31) days (P < 0.01); that of profound II degree wound was (20.10 +/- 3.40) days, (17.20 +/- 3.12) days and (15.10 +/- 3.81) days respectively (P < 0.01, P < 0.05). The healed wound of profound II degree was elastic and tough in regions B and C, while that was not elastic and tough, and congestive in region A.

CONCLUSION

The above results indicate that rhEGF can enhance burn wound healing markedly and that a combination rhEGF and Su Yu Ping has more significant effect than rhEGF alone and is recommended for clinical application.

Polyethylene glycol-coated liposomes for oral delivery of recombinant human epidermal growth factor

The present study was to investigate the feasibility of oral delivery of recombinant human epidermal growth factor (rhEGF). Polyethylene glycol (PEG)-coated liposomes containing rhEGF was prepared and evaluated for their stability and permeability in Caco-2 cells. In the animal study, we also determined plasma concentration and gastric ulcer healing effect after oral administration of rhEGF liposomes or the solution. Encapsulation of rhEGF into liposomes, suppressed the degradation in Caco-2 cell homogenate compared with the solution. The flux of rhEGF from dipalmitoylphosphatidylcholine (DPPC) liposome across Caco-2 cell monolayer from the apical to basolateral side was three times greater than that from phosphatidylcholine (PC) liposome or the solution. After oral administration of rhEGF liposomes or the solution in rats, the area under the concentration-time curve (AUC) of rhEGF increased 1.7- and 2.5-fold for PC and DPPC liposomes, respectively. The gastric ulcer healing effect was significantly increased in DPPC liposome compared with PC liposome and the solution. The enhanced curative ratio of rhEGF encapsulated into DPPC liposome may be due to the resistance to enzyme degradation, higher permeability and increased plasma AUC. Therefore, PEG-coated liposomes containing rhEGF could be used as an oral delivery formulation with enhanced encapsulation efficiency.

[Clinical observation of the long-term effects of rhEGF on deep partial-thickness burn wounds]

OBJECTIVE

To evaluate the safety and long-term effect of recombinant human epithelial growth factor (rhEGF) on deep partial-thickness burn wounds.

METHODS

Thirty-seven burn patients were enrolled in this study and were observed by randomized, double-blinded and placebo-controlled protocol. An area of deep partial-thickness burn wounds from each patient was divided into control (C) and treatment (T) portions. The wound in C was treated with normal saline while that in T with rhEGF. The patients were followed-up for 1 and 4 years after wound healing. The healed wounds were evaluated by modified Vancouver scar scale in terms of scar index (SI).

RESULTS

1 year after wound healing, it was found that the SI in T group (7.19 +/- 1.67) was obviously lower than that in C group (8.92 +/- 1.78, P < 0.01). The SI in T group (6.12 +/- 1.54) was still evidently lower than that in C group (8.09 +/- 1.81, P < 0.01) four years after wound healing. There were no signs of development of tumor or cancer in all the tested burn wound areas.

CONCLUSION

External application of rhEGF might be beneficial to the healing quality of deep partial-thickness burn wound with less scar formation and better long-term effects, and it is safe.

Human epidermal growth factor enhances healing of diabetic foot ulcers

OBJECTIVE

To study the healing effect of recombinant human epidermal growth factor (hEGF) on diabetic foot ulcers.

RESEARCH DESIGN AND METHODS

A total of 127 consecutive patients were screened and 61 diabetic subjects were recruited into this double-blind randomized controlled study. Predetermined criteria were used for diagnosis and classification of the diabetic wound. The patients were randomized into three groups. All patients attended our Diabetes Ambulatory Care Center every other week for joint consultation with the diabetologist and the podiatrist. Group 1 (control) was treated with Actovegin 5% cream (Actovegin), group 2 with Actovegin plus 0.02% (wt/wt) hEGF, and group 3 with Actovegin plus 0.04% (wt/wt) hEGF. The study end point was the complete closure of the wound. Failure to heal was arbitrarily defined as incomplete healing after 12 weeks.

RESULTS

Final data were obtained from 61 patients randomly assigned into three groups. The mean ages of the patients, wound sizes, wound duration, metabolic measurements, and comorbidities were comparable within groups, except that group 3 had more female patients. Mean follow-up for the patients was 24 weeks. Data were cutoff at 12 weeks, and results were analyzed by intention to treat. After 12 weeks, in group 1 (control) eight patients had complete healing, two patients underwent toe amputation, and nine had nonhealing ulcers. In group 2 (0.02% [wt/wt] hEGF) 12 patients experienced wound healing, 2 had toe amputations, and 7 had nonhealing ulcers. Some 20 of 21 patients in group 3 (0.04% [wt/wt] hEGF) showed complete wound healing. Healing rates were 42.10, 57.14, and 95% for the control, 0.02% (wt/wt) hEGF, and 0.04% (wt/wt) hEGF groups, respectively. Kaplan-Meier survival analysis suggested that application of cream with 0.04% (wt/wt) hEGF caused more ulcers to heal by 12 weeks and increased the rate of healing compared with the other treatments (log-rank test, P = 0.0003).

CONCLUSIONS

Our data support the contention that application of hEGF-containing cream, in addition to good foot care from a multidisciplinary team, significantly enhances diabetic foot ulcer wound healing and reduces the healing time.

The effects of hyaluronic acid, epidermal growth factor, and mitomycin in an experimental model of acute traumatic tympanic membrane perforation

HYPOTHESIS

The goal of this study was to evaluate the effects of hyaluronic acid, epidermal growth factor, and mitomycin C on the healing of acute experimental traumatic perforations of the tympanic membrane.

BACKGROUND

Most acute perforations of the tympanic membrane heal spontaneously. However, some form of surgical treatment (i.e., myringoplasty) is needed for nonhealing perforations. Because the closure occurs by squamous epithelial migration, drugs that stimulate this regenerative process may aid in the closure of the perforation, obviating the need for more extensive treatments.

METHODS

Bilateral perforations of the tympanic membrane were created in 30 rats, divided into three groups (A, B, C). The perforations in the right ears were treated with hyaluronic acid, epidermal growth factor, or mitomycin C. Those in the left ears were left untreated for comparison. To examine the healing process in different periods, 5 animals were killed in each group at days 3, 5, 7, 9 and 14. The other 5 animals in each group were observed daily to determine the duration of perforation closures. Thirty surgical specimens (5 right sides from each group and all 15 left sides in all groups) were histopathologically examined for tympanic membrane thickness, fibroblastic reaction, neovascularization, and crust morphology.

RESULTS

Hyaluronic acid and epidermal growth factor applications significantly shortened the healing in acute experimental traumatic perforations of the tympanic membrane (p = 0.0432); however, the difference between them was not significant (p = 0.3160). On the other side, tympanic membrane perforations treated with topical mitomycin C showed no evidence of closure. There were no significant differences in the histologic parameters between the treated groups and their contralateral control ears.

CONCLUSION

Hyaluronic acid and epidermal growth factor accelerated the closure of acute tympanic membrane perforations in rats. This may make them clinically useful in augmenting the efficiency of conservative treatments of acute perforations of the tympanic membrane.

Cellular retention of radioactivity and increased radiation dose. Model experiments with EGF-dextran

Targeting of tumor cells with radiolabeled biomolecules is a possible approach to inactivate disseminated tumor cells. However, rapid degradation of the biomolecules after cellular internalization and subsequent excretion of the radioactivity is a problem. We studied the possibility of using dextran as a carrier of radionuclides to improve the intracellular retention. An EGF-dextran conjugate, aimed for targeting of tumor cells overexpressing the EGF-receptor, was used as model. Retention tests were performed with (125)I on different parts: [(125)I]-EGF-dextran-[(125)I], [(125)I]-EGF-dextran and EGF-dextran-[(125)I]. Comparisons were made with [(125)I]-EGF. The radiolabeled compounds were incubated with cultured glioma cells for different times. The cellular retention of radioactivity was then measured for up to 24 h. Expected radiation doses at the cellular level were calculated assuming that (131)I, instead of (125)I, was coupled to EGF and EGF-dextran. The results indicated that the EGF-part of the conjugate was degraded and the EGF-attached radioactivity was rapidly excreted, whereas radioactivity on dextran was retained intracellularly to a high degree, i.e. 70-80% of the radioactivity bound to dextran was still cell-associated after 24 h. The retention after 24 h was significantly higher (p < 0.001) when the radioactivity was on the dextran instead of the EGF-part. The radiolabeled EGF-dextran had a notably high specific radioactivity; up to 11 MBq/microg. There was potential for at least hundred times increased radiation dose per receptor interaction when the radioactivity was on the dextran part. The advantage with radioactivity on the dextran part was the high cellular retention and the high specific radioactivity (higher than previously reported for other residualizing labels) without severe loss of receptor specific binding. Thus, dextran seems suitable as a carrier of radionuclides aimed for therapy and gives potential for a highly increased radiation dose.

EGF amplifies the replacement of parvalbumin-expressing striatal interneurons after ischemia

EGF promotes proliferation and migration of stem/progenitor cells in the normal adult brain. The effect of epidermal growth factor on neurogenesis in ischemic brain is unknown, however. Here we show that intraventricular administration of EGF and albumin augments 100-fold neuronal replacement in the injured adult mouse striatum after cerebral ischemia. Newly born immature neurons migrate into the ischemic lesion and differentiate into mature parvalbumin-expressing neurons, replacing more than 20% of the interneurons lost by 13 weeks after ischemia and representing 2% of the total BrdU-labeled cells. These data suggest that administration of EGF and albumin could be used to manipulate endogenous neurogenesis in the injured brain and to promote brain self-repair.