Antifibrogenic effects of liposome-encapsulated IFN-alpha2b cream on skin wounds in a fibrotic rabbit ear model

Liposome-Encapsulated Botulinum Toxin A in Treatment of Functional Bladder Disorders

Botulinum toxin A (BoNT-A) intravesical injections have been used to treat patients with refractory functional bladder disorders such as overactive bladder (OAB) and interstitial cystitis/bladder pain syndrome (IC/BPS), but the risk of adverse events and the need for repeated injections continue to prevent widespread application of this treatment. Liposomes are vesicles that comprise concentric phospholipid layers and an aqueous core; their flexible compositions enable them to adsorb and fuse with cell membranes and to deliver drugs or proteins into cells. Therefore, liposomes have been considered as promising vehicles for the less invasive delivery of BoNT-A. In previous placebo-controlled trials including patients with OAB refractory to medical treatment, it was shown that liposomal BoNT-A could significantly decrease the frequency and urgency of urination. In patients with IC/BPS, it was shown that liposomal BoNT-A could also improve bladder pain, but the therapeutic efficacy was not superior to that of the placebo. As the therapeutic mechanisms of BoNT-A include the decreased expression of nerve growth factors, P2X3 receptors, and vanilloid receptors on C-fibers, liposomal BoNT-A might play a more promising role in the treatment of bladder oversensitivity. This article features the contemporary literature regarding BoNT-A, liposomes, and liposomal BoNT-A treatment for functional bladder disorders and potential clinical applications in the future.

Pharmaceutical Prophylaxis of Scarring with Emphasis on Burns: A Review of Preclinical and Clinical Studies

Significance: The worldwide estimate of burns requiring medical attention each year is 11 million. Each year in the United States, ∼486,000 burn injuries receive medical attention, including 40,000 hospitalizations. Scars resulting from burns can be disfiguring and impair functions. The development of prophylactic drugs for cutaneous scarring could improve the outcomes for burns, traumatic lacerations (>6 million/year treated in U.S. emergency rooms), and surgical incisions (∼250 million/year worldwide). Antiscar pharmaceuticals have been estimated to have a market of $12 billion. Recent Advances: Many small molecules, cells, proteins/polypeptides, and nucleic acids have mitigated scarring in animal studies and clinical trials, but none have received Food and Drug Administration (FDA) approval yet. Critical Issues: The development of antiscar pharmaceuticals involves the identification of the proper dose, frequency of application, and window of administration postwounding for the indicated wound. Risks of infection and impaired healing must be considered. Scar outcome needs to be evaluated after scars have matured. Future Directions: Once treatments have demonstrated safety and efficacy in rodent and/or rabbit and porcine wound models, human testing can begin, such as on artificially created wounds on healthy subjects and on bilateral-surgical wounds, comparing treatments versus vehicle controls on intrapatient-matched wounds, before testing on separate cohorts of patients. Given the progress made in the past 20 years, FDA-approved drugs for improving scar outcomes may be expected.

Efficacy of topical Miltefosine formulations in an experimental model of cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) is a neglected tropical disease endemic in ~ 90 countries, with an increasing incidence. Presently available pharmacotherapy implies the systemic administration of moderately/very toxic drugs. Miltefosine (Milt) is the only FDA-approved drug to treat CL via the oral route (Impavido®). It produces side effects; in particular, teratogenic effects are of concern. A topical treatment would have the great advantage of minimising the systemic circulation of the drug, preventing side effects. We prepared dispersions containing Milt and liposomes of different compositions to enhance/modulate trans-epidermal penetration and evaluated in vitro and in vivo efficacy and toxicity, in vitro release rate of the drug and particles size stability with time. Treatments were topically administered to BALB/c mice infected with Leishmania (Leishmania) amazonensis. The dispersions containing 0.5% Milt eliminated 99% of the parasites and cured the lesions with a complete re-epithelisation, no visible scar and re-growth of hair. Fluid liposomes decreased the time to heal the lesion and the time needed to eliminate viable amastigotes from the lesion site. Relapse of the infection was not found 1 month after treatment in any case. Ultraflexible liposomes on the other hand had no significant in vitro effect but decreased in vivo efficacy. A topical Milt formulation including fluid liposomes seems a promising treatment against CL.

Nonsurgical Management of Hypertrophic Scars: Evidence-Based Therapies, Standard Practices, and Emerging Methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

Potential of Pluronics® P-123 and F-127 as nanocarriers of anti-Leishmania chemotherapy

Leishmaniasis is a neglected disease and drugs approved for its treatment often lead to abandonment, failure of therapy and even death. Photodynamic therapy (PDT) has been shown to be a promising, non-invasive and selective for a target region without requiring high-cost technology. Usually, it is employed a photosensitizing agent (PS) incorporated into nanoparticles (NP). Pluronics^® P-123 and F-127 micelles are very interesting aqueous NP promoting efficient and selective delivery and less adverse effects. This study aimed to detect the activity of Pluronics^® P-123 and F-127 themselves since there is a scarcity of data on these NP activities without drugs incorporation. This study evaluated, in vitro, the activity of Pluronics^® against promastigotes and amastigotes of Leishmania amazonensis and also their cytotoxicities. Additionally, the determination of the mitochondria membrane potential in promastigotes, internalization of these Pluronics^® in the parasite membrane and macrophages and its stability in the culture medium was evaluated. Results showed that Pluronics^® did not cause significant damage to human red cells and promastigotes. The P-123 and F-127 inhibited the survival rate of L. amazonensis amastigotes, and also presented loss of mitochondrial membrane potential on promastigotes. The Pluronics^® showed low cytotoxic activity on J774A.1 macrophages, while only P-123 showed moderate cytotoxicity for BALB/c macrophages. The stability of P-123 and F-127 in culture medium was maintained for ten days. In conclusion, the NP studied can be used for incorporating potent leishmanicidal chemotherapy, due to their selectivity towards macrophages, being a promising system for the treatment of cutaneous leishmaniasis.

Deferiprone has anti-inflammatory properties and reduces fibroblast migration in vitro

Normal wound healing is a highly regulated and coordinated process. However, tissue injury often results in inflammation with excessive scar tissue formation after 40-70% of operations. Here, we evaluated the effect of the iron chelator deferiprone on inflammation and the migration of primary nasal fibroblasts and primary human nasal epithelial cells (HNECs) in vitro. The cytotoxicity of deferiprone was examined by the lactate dehydrogenase assay on primary nasal fibroblasts and air-liquid interface (ALI) cultures of HNECs. Wound closure was observed in scratch assays by using time-lapse confocal scanning laser microscopy. Interleukin-6 (IL-6) and type I and III collagen protein levels were determined by ELISA. Intracellular Reactive Oxygen Species (ROS) activity was measured by utilizing the fluorescent probe H2DCFDA. Deferiprone at 10 mM concentration was non-toxic to primary fibroblasts and HNECs for up to 48 hours application. Deferiprone had significant dose-dependent inhibitory effects on the migration, secreted collagen production and ROS release by primary nasal fibroblasts. Deferiprone blocked Poly (I:C)-induced IL-6 production by HNECs but did not alter their migration in scratch assays. Deferiprone has the potential to limit scar tissue formation and should be considered in future clinical applications.

Keloids and Hypertrophic Scars: A Spectrum of Clinical Challenges

Since their earliest description, keloids and hypertrophic scars have beleaguered patients and clinicians alike. These scars can be aesthetically disfiguring, functionally debilitating, emotionally distressing, and psychologically damaging, culminating in a significant burden for patients. Our current understanding of keloid pathophysiology has grown and continues to advance while molecular biology, genetics, and technology provide ever-deepening insight into the nature of wound healing and the pathologic perturbations thereof. Greater understanding will lead to the development and application of refined therapeutic modalities. This article provides an overview of our current understanding of keloids, highlighting clinical characteristics and diagnostic criteria while providing a comprehensive summary of the many therapeutic modalities available. The proposed mechanism, application, adverse events, and reported efficacy of each modality is evaluated, and current recommendations are summarized.

The Role of Chemokines in Fibrotic Wound Healing

Significance: Main dermal forms of fibroproliferative disorders are hypertrophic scars (HTS) and keloids. They often occur after cutaneous wound healing after skin injury, or keloids even form spontaneously in the absence of any known injury. HTS and keloids are different in clinical performance, morphology, and histology, but they all lead to physical and psychological problems for survivors. Recent Advances: Although the mechanism of wound healing at cellular and tissue levels has been well described, the molecular pathways involved in wound healing, especially fibrotic healing, is incompletely understood. Critical Issues: Abnormal scars not only lead to increased health-care costs but also cause significant psychological problems for survivors. A plethora of therapeutic strategies have been used to prevent or attenuate excessive scar formation; however, most therapeutic approaches remain clinically unsatisfactory. Future Directions: Effective care depends on an improved understanding of the mechanisms that cause abnormal scars in patients. A thorough understanding of the roles of chemokines in cutaneous wound healing and abnormal scar formation will help provide more effective preventive and therapeutic strategies for dermal fibrosis as well as for other proliferative disorders.

The therapeutic potential of a C-X-C chemokine receptor type 4 (CXCR-4) antagonist on hypertrophic scarring in vivo

Effective prevention and treatment of hypertrophic scars (HTSs), a dermal form of fibrosis that frequently occurs following thermal injury to deep dermis, are unsolved significant clinical problems. Previously, we have found that stromal cell-derived factor 1/CXCR4 signaling is up-regulated during wound healing in burn patients and HTS tissue after thermal injury. We hypothesize that blood-borne mononuclear cells are recruited into wound sites after burn injury through the chemokine pathway of stromal cell-derived factor 1 and its receptor CXCR4. Deep dermal injuries to the skin are often accompanied by prolonged inflammation, which leads to chemotaxis of mononuclear cells into the wounds by chemokine signaling where fibroblast activation occurs and ultimately HTS are formed. Blocking mononuclear cell recruitment and fibroblast activation, CXCR4 antagonism is expected to reduce or minimize scar formation. In this study, the inhibitory effect of CXCR4 antagonist CTCE-9908 on dermal fibrosis was determined in vivo using a human HTS-like nude mouse model, in which split-thickness human skin is transplanted into full-thickness dorsal excisional wounds in athymic mice, where these wounds subsequently develop fibrotic scars that resemble human HTS as previously described. CTCE-9908 significantly attenuated scar formation and contraction, reduced the accumulation of macrophages and myofibroblasts, enhanced the remodeling of collagen fibers, and down-regulated the gene and protein expression of fibrotic growth factors in the human skin tissues. These findings support the potential therapeutic value of CXCR4 antagonist in dermal fibrosis and possibly other fibroproliferative disorders.

A facilely fabricated in vivo hypertrophic scar model through continuous gradient elastic tension

In this study, a facile, reproducible, and economical rat HScs model was successfully fabricated, driven through elastic tension.

Drug delivery systems for the topical treatment of cutaneous leishmaniasis

INTRODUCTION

The parenteral administration of pentavalent antimonials for the treatment of all forms of leishmaniasis, including cutaneous leishamniasis (CL), has several limitations. Therapy is long, requiring repeated doses and the adverse reactions are frequent. Topical treatment is an attractive alternative for CL, offering significant advantages over systemic therapy: fewer adverse effects, ease of administration, and lower costs.

AREAS COVERED

This review covers, from 1984 to the present, the progress achieved for the development of topical treatment for CL, using different drugs such as paromomycin (PA), imiquimod, amphotericin B (AmB), miltefosine, and buparvaquone. PA is the most commonly studied drug, followed by AmB and Imiquimod. These drugs were incorporated in conventional dosage forms or loaded in lipid nanocarries, which have been used mainly for improved skin delivery and antileishmanial activity.

EXPERT OPINION

Developing an effective topical treatment for CL using these antileishmanial drugs still remains a great challenge. Insights into the most promising delivery strategies to improve treatment of CL with PA and AmB using conventional dosage forms, lipid nanocarriers, and combined therapy are presented and discussed. The results obtained with combined therapy and alternative delivery systems are promising perspectives for improving topical treatment of CL.

Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 in the formation of postburn hypertrophic scar (HTS)

Recent data support the involvement of stromal cell-derived factor 1 (SDF-1) in the homing of bone marrow-derived stem cells to wound sites during skeletal, myocardial, vascular, lung, and skin wound repair as well as some fibrotic disorders via its receptor CXCR4. In this study, the role of SDF-1/CXCR4 signaling in the formation of hypertrophic scar (HTS) following burn injury and after treatment with systemic interferon α2b (IFNα2b) is investigated. Studies show SDF-1/CXCR4 signaling was up-regulated in burn patients, including SDF-1 level in HTS tissue and serum as well as CD14+ CXCR4+ cells in the peripheral blood mononuclear cells. In vitro, dermal fibroblasts constitutively expressed SDF-1 and deep dermal fibroblasts expressed more SDF-1 than superficial fibroblasts. Lipopolysaccharide increased SDF-1 gene expression in fibroblasts. Also, recombinant SDF-1 and lipopolysaccharide stimulated fibroblast-conditioned medium up-regulated peripheral blood mononuclear cell mobility. In the burn patients with HTS who received subcutaneous IFNα2b treatment, increased SDF-1/CXCR4 signaling was found prior to treatment which was down-regulated after IFNα2b administration, coincident with enhanced remodeling of their HTS. Our results suggest that SDF-1/CXCR4 signaling is involved in the development of HTS by promoting migration of activated CD14+ CXCR4+ cells from the bloodstream to wound sites, where they may differentiate into fibrocyte and myofibroblasts and contribute to the development of HTS.

Effects of botulinum toxin type a on collagen deposition in hypertrophic scars

A recent study reported that Botulinum toxin type A (BTXA) could inhibit the growth of hypertrophic scars and improve their appearance. However, the mechanism of BTXA's action on hypertrophic scars is still unknown. Some in vitro studies had shown BTXA could alleviate hypertrophic scars by acting on the biological behavior of fibroblasts, but there are few in vivo experiments, especially animal model experiments, supporting these findings. The aim of the study reported herein was to investigate the effect of BTXA on collagen deposition on hypertrophic scars in a rabbit ear model and partially clarify the mechanism of BTXA on the hypertrophy of scars. The rabbit hypertrophic scar model was used and eight rabbits were employed. BTXA was injected into the hypertrophic scar tissue of one ear; and the other ear in the same rabbit was the control without BTXA injection. The scar thickness and deposition of collagen was examined through immune histochemistry including haematoxylin and eosin (H&E) and Masson trichrome staining. The thicknesses of hypertrophic scars in the BTXA treatment group were obviously lower than in the control groups (P < 0.01). H&E and Masson staining showed that collagen fibers were stained blue. Compared with the treatment group, the collagen fibers were thicker and the arrangement of collagen fibers were disordered in the control group. This study used the rabbit ear model of hypertrophic scars to assess the effects of BTXA on scar hypertrophy. The application of BTXA may be useful for inhibiting hypertrophic scars.

The effect of surgical denervation on prevention of excessive dermal scarring: a study on rabbit ear hypertrophic scar model

BACKGROUND

Previous reports have suggested that the extent of wound contraction, epithelisation and total healing time were influenced by denervation of tissues. In this article, we studied for the first time the effect of sensory denervation on prevention of excessive dermal scarring.

MATERIALS AND METHODS

Sixteen New Zealand white rabbits were used. Denervation of the right ears was performed by surgical excision of two main sensory nerves. Dissections were also performed on left ears without any nerve excision for the control group. After 14 days of follow-up and confirmation of tissue denervation, an excessive dermal scarring model as defined by Morris et al. was made by surgery on both ears. Twenty-eight days after making the wounds, the tissues were extirpated for analyses. The scars were evaluated by the scar elevation index (SEI), epithelisation time and inflammatory cell count.

RESULTS

The SEI of the denervated side scars was significantly lower than that of the non-denervated side. The rate and timing of total epithelisation and inflammatory cell count between groups yielded no difference.

CONCLUSIONS

In this study, the surgical denervation skin reduced scarring. It was suggested that understanding the exact role of sensory nerves and neural mediators in excessive dermal scarring is necessary for the prevention and treatment of scarring.

Development of a three-dimensional human skin equivalent wound model for investigating novel wound healing therapies

Numerous difficulties are associated with the conduct of preclinical studies related to skin and wound repair. Use of small animal models such as rodents is not optimal because of their physiological differences to human skin and mode of wound healing. Although pigs have previously been used because of their human-like mode of healing, the expense and logistics related to their use also renders them suboptimal. In view of this, alternatives are urgently required to advance the field. The experiments reported herein were aimed at developing and validating a simple, reproducible, three-dimensional ex vivo de-epidermised dermis human skin equivalent wound model for the preclinical evaluation of novel wound therapies. Having established that the human skin equivalent wound model does in fact &#x201C;heal," we tested the effect of two novel wound healing therapies. We also examined the utility of the model for studies exploring the mechanisms underpinning these therapies. Taken together the data demonstrate that these new models will have wide-spread application for the generation of fundamental new information on wound healing processes and also hold potential in facilitating preclinical optimization of dosage, duration of therapies, and treatment strategies prior to clinical trials.

14-3-3 sigma associates with cell surface aminopeptidase N in the regulation of matrix metalloproteinase-1

Matrix metalloproteinases (MMPs) are implicated in the degradation of the extracellular matrix during development and tissue repair, as well as in pathological conditions such as tumor invasion and fibrosis. MMP expression by stromal cells is partly regulated by signals from the neighboring epithelial cells. Keratinocyte-releasable 14-3-3sigma, or stratifin, acts as a potent MMP-1-stimulatory factor in fibroblasts. However, its mechanism of transmembrane signaling remains unknown. Ectodomain biotin labeling, serial affinity purification and mass spectroscopy analysis revealed that the stratifin associates with aminopeptidase N (APN), or CD13, at the cell surface. The transient knockdown of APN in fibroblasts eliminated the stratifin-mediated p38 MAP kinase activation and MMP-1 expression, implicating APN in a receptor-mediated transmembrane signaling event. Stratifin deletion studies implicated its C-terminus as a potential APN-binding site. Furthermore, the dephosphorylation of APN ectodomains reduced its binding affinity to the stratifin. The presence of a phosphorylated serine or threonine residue in APN has been implicated. Together, these findings provide evidence that APN is a novel cell surface receptor for stratifin and a potential target in the regulation of MMP-1 expression in epithelial-stromal cell communication.

Hypertrophic scars and keloids--a review of their pathophysiology, risk factors, and therapeutic management

BACKGROUND

Hypertrophic scars and keloids result from an abnormal fibrous wound healing process in which tissue repair and regeneration-regulating mechanism control is lost. These abnormal fibrous growths present a major therapeutic dilemma and challenge to the plastic surgeon because they are disfiguring and frequently recur.

OBJECTIVE

To provide updated clinical and experimental information on hypertrophic scars and keloids so that physicians can better understand and properly treat such lesions.

METHODS

A Medline literature search was performed for relevant publications and for diverse strategies for management of hypertrophic scars and keloids.

CONCLUSION

The growing understanding of the molecular processes of normal and abnormal wound healing is promising for discovery of novel approaches for the management of hypertrophic scars and keloids. Although optimal treatment of these lesions remains undefined, successful healing can be achieved only with combined multidisciplinary therapeutic regimens.

Expression of collagen genes in the cones of skin in the Duroc/Yorkshire porcine model of fibroproliferative scarring

During the past decades there has been minimal improvement in prevention and treatment of hypertrophic scarring. Reasons include the lack of a validated animal model, imprecise techniques to dissect scar into the histologic components, and limited methodology for measurement of gene expression. These problems have been addressed with the Duroc/Yorkshire model of healing, laser capture microdissection, and the Affymetrix Porcine GeneChip. Here we compared collagen gene expression in fibroproliferative healing in the Duroc breed to nonfibroproliferative healing in the Yorkshires. We made shallow and deep dorsal wounds, biopsied at 1, 2, 3, 12, and 20 weeks. We sampled the dermal cones by laser capture microdissection, extracted and amplified the RNA, and hybridized Affymetrix Porcine GeneChips. We also obtained samples of human hypertrophic scar approximately 20 weeks postinjury. Data were normalized and statistical analysis performed with mixed linear regression using the Bioconductor R/maanova package. Genes for further analysis were also restricted with four biologic criteria, including that the 20-week deep Duroc expression match the human samples. Eleven collagen genes and seven collagen types were differentially over expressed in deep Duroc wounds including 1a1, 1a2, 3a1, 4a1, 4a2, 5a1, 5a2, 5a3, 6a3 (transcript variant 5), 14a1 and 15a1. COL7a1 gene was differentially under expressed in deep Duroc wounds. The results suggest that collagens I, III, IV, V, VI, VII, XIV, and XV [corrected] are involved in the process of fibroproliferative scarring. With these clues, we will attempt to construct the regulatory pathway(s) of fibroproliferative healing.

Novel Delivery Systems for Interferons

Interferons, IFNs, are among the most widely studied and clinically used biopharmaceuticals. Despite their invaluable therapeutic roles, the widespread use of IFNs suffers from some inherent limitations, mainly their relatively short circulation lifespan and their unwanted effects on some non-target tissues. Therefore, both these constraints have become the central focus points for the research efforts on the development of a variety of novel delivery systems for these therapeutic agents with the ultimate goal of improving their therapeutic end-points. Generally, the delivery systems currently under investigation for IFNs can be classified as particulate delivery systems, including micro- and nano-particles, liposomes, minipellets, cellular carriers, and non-particulate delivery systems, including PEGylated IFNs, other chemically conjugated IFNs, immunoconjugated IFNs, and genetically conjugated IFNs. All these strategies and techniques have their own possibilities and limitations, which should be taken into account when considering their clinical application. In this article, currently studied delivery systems/techniques for IFN delivery have been reviewed extensively, with the main focus on the pharmacokinetic consequences of each procedure.

Nonsurgical management of hypertrophic scars: evidence-based therapies, standard practices, and emerging methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

Native Human IFN-αIs a More Potent Suppressor of HDF Response to Profibrotic Stimuli Than Recombinant Human IFN-α

Interferon-alpha(IFN-alpha) inhibits fibroblast proliferation, differentiation into myofibroblasts, and extracellular matrix synthesis, which are key events during both normal wound repair and fibrotic lesion formation. Unlike recombinant human IFN-alpha (rHuIFN-alpha), a native human IFN-alpha (nHuIFN-alpha) consists of several IFN-alpha subtypes and traces of other cytokines produced by the Sendai virus-stimulated human leukocytes. This study compares the antifibrotic effect of nHuIFN-alpha and rHuIFN-alpha in normal human dermal fibroblasts (HDFs). Treatment of HDF culture with nHuIFNA-alpha markedly affects HDF viability, whereas different rHuIFN-alpha subtypes show various effects. Two of twelve rHuIFN-alpha subtypes (IFN-alpha B2 and IFN-alpha K) significantly reduce cell viability of HDFs compared with nontreated HDFs. However, nHuIFN-alpha significantly reduces HDF cell viability in comparison to both nontreated cells and cells treated with rHuIFN-alpha. The 50% inhibitory concentration (IC(50)) varied 10-fold between nHuIFN-alpha and rHuIFN-alpha (1,103 IU/mL and 10,762 IU/mL, respectively). The impact on procollagen type I mRNA synthesis level is comparable at low doses of IFN (100 and 500 IU/mL), whereas at the dose of 1,000 IU/mL, nHuIFN-alpha shows higher repression of collagen type I gene than does rHuIFN-alpha. Both, nHuIFN-alpha and rHuIFN-alpha antagonize the effect of exogenous transforming growth factor-beta (TGF-beta) and interleukin-4 (IL-4) as measured by the alpha-smooth muscle actin (alpha -SMA) and procollagen type I mRNA level, but the effect of nHuIFN-alpha is more pronounced. This study suggests that nHuIFN-alpha is a more potent suppressor of the HDF response to profibrotic stimuli than rHuIFN-alpha, probably because of the synergism between different IFN-alpha subtypes and antifibrotic cytokines and factors.

Magnetic nanofactories: Localized synthesis and delivery of quorum-sensing signaling molecule autoinducer-2 to bacterial cell surfaces

Magnetic 'nanofactories', for localized manufacture and signal-guided delivery of small molecules to targeted cell surfaces, are demonstrated. They recruit nearby raw materials for synthesis, employ magnetic mobility for capture and localization of target cells, and deliver molecules to cells triggering their native phenotypic response, but with user-specified control. Our nanofactories, which synthesize and deliver the "universal" bacterial quorum-sensing signal molecule, autoinducer AI-2, to the surface of Escherichia coli, are assembled by first co-precipitating nanoparticles of iron salts and the biopolymer chitosan. E. coli AI-2 synthases, Pfs and LuxS, constructed with enzymatically activatable "pro-tags", are then covalently tethered onto the chitosan. These enzymes synthesize AI-2 from metabolite S-adenosylhomocysteine. Chitosan serves as a molecular scaffold and provides cell capture ability; magnetite provides stimuli responsiveness. These magnetic nanofactories are shown to modulate the natural progression of quorum-sensing activity. New prospects for small molecule delivery, based on localized synthesis, are envisioned.

Recent advances in intravesical drug/gene delivery

Targeting of drugs administered systemically relies on the higher affinity of ligands for specific receptors to obtain selectivity in drug response. However, achieving the same goal inside the bladder is much easier with an intelligent pharmaceutical approach that restricts drug effects by exploiting the pelvic anatomical architecture of the human body. This regional therapy involves placement of drugs directly into the bladder through a urethral catheter. It is obvious that drug administration by this route holds advantage in chemotherapy of superficial bladder cancer, and it has now become the most widely used treatment modality for this ailment. In recent years, the intravesical route has also been exploited either as an adjunct to an oral regimen or as a second-line treatment for neurogenic bladder. (Lamm, D. L.; Griffith, J. G. Semin. Urol. 1992, 10, 39-44. Igawa, Y.; Satoh, T.; Mizusawa, H.; Seki, S.; Kato, H.; Ishizuka, O.; Nishizawa, O. BJU Int. 2003, 91, 637-641.) Instillation of DNA via this route using different vectors has been able to restrict the transgene expression in organs other than bladder. The present review article will discuss the shortcomings of the current options available for intravesical drug delivery (IDD) and lay a perspective for future developments in this field.

Keloids and scars: a review of keloids and scars, their pathogenesis, risk factors, and management

PURPOSE OF REVIEW

The precise mechanisms of normal and abnormal scar formation have long remained a mystery despite the extensive literature regarding wound healing. Only recently have researchers begun to delineate the complex biochemical signaling pathways that regulate these processes. This article reviews basic wound healing, while focusing on medicine's latest understanding of the development and treatment of keloids and hypertrophic scars.

RECENT FINDINGS

The importance of the transforming growth factor-beta signaling pathways and the related downstream effector molecules has proven to offer a new detailed view of scar biology. Regulation of scar metabolism with regards to collagen and wound matrix degradation is likewise showing promise in generating alternate therapies to treat abnormal scars.

SUMMARY

Understanding the exact process of normal and abnormal scar formation will help define better ways to successfully manage and potentially prevent abnormal healing like hypertrophic scars and keloids.