Periprosthetic breast capsules contain the fibrogenic cytokines TGF-beta1 and TGF-beta2, suggesting possible new treatment approaches

Incidence and Risk Assessment of Capsular Contracture in Breast Cancer Patients following Post-Mastectomy Radiotherapy and Implant-Based Reconstruction

Our study aims to identify the risk factors and dosimetry characteristics associated with capsular contracture.

METHODS

We retrospectively analyzed 118 women with breast cancer who underwent PMRT following an IBR between 2010 and 2022. Patients were treated with PMRT of 50.0-50.4 Gy in 25-28 fractions. Capsular contracture was categorized according to the Baker Classification for Reconstructed Breasts.

RESULTS

After a median follow-up of 22 months, the incidence of clinically relevant capsular contracture (Baker III-IV) was 22.9%. Overall, capsular contracture (Baker I-IV) occurred in 56 patients (47.5%) after a median of 9 months after PMRT. The rate of reconstruction failure/implant loss was 25.4%. In the univariate analysis, postoperative complications (prolonged pain, prolonged wound healing, seroma and swelling) and regional nodal involvement were associated with higher rates of capsular contracture (p = 0.017, OR: 2.5, 95% CI: 1.2-5.3 and p = 0.031, respectively). None of the analyzed dosimetric factors or the implant position were associated with a higher risk for capsular contracture.

CONCLUSION

Postoperative complications and regional nodal involvement were associated with an increased risk of capsular contracture following breast reconstruction and PMRT, while none of the analyzed dosimetric factors were linked to a higher incidence. Additional studies are needed to identify further potential risk factors.

Effect of Carboxymethyl Chitin on Capsule Formation around Silicone Implants: An In Vivo and In Vitro Study

BACKGROUND

Capsular contracture is a serious complication that occurs after augmentation mammaplasty. The authors previously identified that carboxymethyl chitin had an inhibitory effect on capsule formation. This study was performed to elucidate the possible molecular mechanisms through which carboxymethyl chitin inhibits the formation of a capsule around silicone implants.

METHODS

In this study, the authors cultured human dermal fibroblasts and treated them with carboxymethyl chitin in vitro. The difference in proliferation between treated and untreated cells was analyzed through the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Protein levels of transforming growth factor beta-1 and alpha smooth muscle actin (α-SMA) were examined by Western blot analysis. Expression levels of type I and type III collagen were checked by enzyme-linked immunosorbent assay. In vivo, silicone implants were placed under the pectoralis muscle in 12 female rabbits. The thickness of the capsule was measured by histologic analysis, and the effect of carboxymethyl chitin on α-SMA, collagen type I and III expression levels was evaluated by real-time polymerase chain reaction analysis, enzyme-linked immunosorbent assay, Western blot, and immunofluorescence analysis.

RESULTS

In the in vitro study, we confirmed that carboxymethyl chitin inhibited the proliferation of fibroblasts. The protein expression levels of collagen type I, transforming growth factor beta-1, and α-SMA were inhibited by carboxymethyl chitin treatment. In vivo, carboxymethyl chitin treatment reduced capsular thickness and the expression of α-SMA and collagen types I and III in capsules around silicone implants.

CONCLUSION

The authors' results showed that carboxymethyl chitin could influence capsule formation around silicone implants by inhibiting the fibroblast activity, interrupting fibroblast-to-myofibroblast differentiation, and decreasing collagen synthesis.

CLINICAL RELEVANCE STATEMENT

Carboxymethyl chitin influence capsule formation around silicone implants. Although more clinical studies are needed to verify the effect of carboxymethyl chitin on capsular contracture, the authors believe that it will play an effective role in the clinical application of reducing the occurrence of capsular contracture.

Suppression of the fibrotic encapsulation of silicone implants by inhibiting the mechanical activation of pro-fibrotic TGF-β

The fibrotic encapsulation of implants involves the mechanical activation of myofibroblasts and of pro-fibrotic transforming growth factor beta 1 (TGF-β1). Here, we show that both softening of the implant surfaces and inhibition of the activation of TGF-β1 reduce the fibrotic encapsulation of subcutaneous silicone implants in mice. Conventionally stiff silicones (elastic modulus, ~2 MPa) coated with a soft silicone layer (elastic modulus, ~2 kPa) reduced collagen deposition as well as myofibroblast activation without affecting the numbers of macrophages and their polarization states. Instead, fibroblasts around stiff implants exhibited enhanced intracellular stress, increased the recruitment of α_v and β₁ integrins, and activated TGF-β1 signalling. In vitro, the recruitment of α_v integrin to focal adhesions and the activation of β₁ integrin and of TGF-β were higher in myofibroblasts grown on latency-associated peptide (LAP)-coated stiff silicones than on soft silicones. Antagonizing α_v integrin binding to LAP through the small-molecule inhibitor CWHM-12 suppressed active TGF-β signalling, myofibroblast activation and the fibrotic encapsulation of stiff subcutaneous implants in mice.

Comparison of the Effects of Acellular Dermal Matrix and Montelukast on Radiation-Induced Peri-implant Capsular Formation in Rabbits

PURPOSE

Capsular contracture (CC) is a troublesome complication after breast surgery with breast implants, and the risk increases in breast cancer patients after radiotherapy. Studies investigating leukotriene antagonists (eg, montelukast, zafirlukast) found that the acellular dermal matrix (ADM) can help prevent CC. We aimed to compare the effects of ADM and montelukast on CC after irradiation.

METHODS

Eighteen New Zealand white rabbits were randomly divided into 3 groups of 6 each. Miniature cohesive gel implants were inserted into the pocket under the latissimus dorsi muscle. The lateral part was uncovered by the latissimus dorsi muscle. Six animals were included in the control group. In experimental group A (EG-A) (n = 6), the site was partially wrapped with ADM but not covered with muscle. Montelukast (Singulair, 0.2 mg/kg) was administered in experimental group B (EG-B) (n = 6) daily. Groups were irradiated at postoperative day 21 with Co-60 γ rays (25 Gy, single fraction) at the peri-implant area. Rabbits were sacrificed 12 weeks after surgery; implants with peri-implant capsule were harvested. Capsule thickness, collagen pattern, myofibroblast, and transforming growth factor (TGF) β1/2 levels in the peri-implant capsule were evaluated.

RESULTS

On histological evaluation, the capsule was thinner on the lateral aspect (covered with ADM) in EG-A (P = 0.004) and the entire capsule in EG-B (P = 0.004) than in the control group. However, there was no significant difference between EG-A and EG-B (P = 0.073). The collagen distribution pattern was more parallel with low density in the lateral capsular aspect in EG-A, but in the entire capsule in EG-B. The myofibroblast amount (EG-A, P = 0.031; EG-B, P = 0.016) and levels of TGF-β1 and TGF-β2 were reduced in the experimental groups (TGF-β1, EG-A, P = 0.019; TGF-β1, EG-B, P = 0.045; TGF-β2, EG-A, P = 0.018; TGF-β2, EG-B, P = 0.022). There was no significant difference between EG-A and EG-B (myofibroblast, P = 0.201; TGF-β1, P = 0.665; TGF-β2, P = 0.665).

CONCLUSIONS

Acellular dermal matrix and montelukast have a prophylactic effect for CC even when the breast is irradiated. There was no significant difference between ADM and montelukast in preventing capsular formation. The difference is that ADM will only have the effect of covering the capsular formation with ADM and montelukast can cause systemic effects or complications.

Angiotensin-Converting Enzyme Inhibitor Reduces Radiation-Induced Periprosthetic Capsular Fibrosis

BACKGROUND

The capsular contracture is one of the main complications after radiotherapy in patients with implant-based reconstruction. The aim of this study is to evaluate the efficacy of ramipril for the prevention of radiation-induced fibrosis around the silicone implant.

MATERIALS AND METHODS

Thirty Wistar rats in 5 groups were used. Group 1: implant; group 2: implant + radiation; group 3: ramipril + implant; group 4: ramipril + implant + radiation; group 5: sham. Ramipril treatment was started 5 d before surgery and continued for 12 wk after surgery. A mini silicone implant was placed in the back of the rats. A single fraction of 21.5 Gy radiation was applied. Tissues were examined histologically and immunohistochemically (TGF-β1, MMP-2, and TIMP-2 expression). The alteration of plasma TGF-β1 levels was examined before and after the experiment.

RESULTS

After applying implant or implant + radiation, capsular thickness, percentage of fibrotic area, tissue and plasma TGF-β1 levels significantly increased, and MMP-2/TIMP-2 ratio significantly decreased compared with the sham group. In ramipril-treated groups, the decrease in capsular thickness, fibrosis, TGF-β1 positivity, and an increase in MMP-2/TIMP-2 ratio were found significant. In the ramipril + implant + radiation group, the alteration values of TGF-β1 dramatically decreased.

CONCLUSIONS

Our results show that ramipril reduces radiation-induced fibrosis and contracture. The results of our study may be important for the design of the clinical trials required to investigate the effective and safe doses of ramipril, which is an inexpensive and easily tolerated drug, on humans.

Biomedical Implants for Regenerative Therapies

Regenerative therapies aim to develop novel treatments to restore tissue function. Several strategies have been investigated including the use of biomedical implants as three-dimensional artificial matrices to fill the defect side, to replace damaged tissues or for drug delivery. Bioactive implants are used to provide growth environments for tissue formation for a variety of applications including nerve, lung, skin and orthopaedic tissues. Implants can either be biodegradable or non-degradable, should be nontoxic and biocompatible, and should not trigger an immunological response. Implants can be designed to provide suitable surface area-to-volume ratios, ranges of porosities, pore interconnectivities and adequate mechanical strengths. Due to their broad range of properties, numerous biomaterials have been used for implant manufacture. To enhance an implant’s bioactivity, materials can be functionalised in several ways, including surface modification using proteins, incorporation of bioactive drugs, growth factors and/or cells. These strategies have been employed to create local bioactive microenvironments to direct cellular responses and to promote tissue regeneration and controlled drug release. This chapter provides an overview of current bioactive biomedical implants, their fabrication and applications, as well as implant materials used in drug delivery and tissue regeneration. Additionally, cell- and drug-based bioactivity, manufacturing considerations and future trends will be discussed.

Breast reconstruction with breast implants

BACKGROUND

Breast cancer is the most common noncutaneous malignancy among women worldwide. After a breast cancer removal procedure, women are asked to decide about breast reconstruction, mainly to improve their life quality, and they can choose from among many options. Broadly, there are two different types of breast reconstruction procedures: prosthetic implant-based reconstruction and autologous tissue-based reconstruction.

METHODS

Implant-breast reconstruction is a minimally invasive procedure compared with autologous breast reconstruction. It is associated with fewer short- and long-term complications.

RESULTS

The ideal candidates for implant-based reconstruction are patients with non-redundant soft tissue coverage, who desire a moderate sized non-ptotic breast and have not been previously irradiated.

CONCLUSION

The state of the art for implant-breast reconstruction is briefly described in this article.

Botulinum Toxin A Plays an Important Role in the Placement of Implants Deep Within the Pectoralis Major Muscle for Mammaplasty: A Systematic Review and Meta-analysis

BACKGROUND

Breast prosthesis implants have been safely and efficiently used in the plastic surgery department. With the increasing demand for aesthetics, these silicon implants were not only used in breast augmentation surgery but also in breast reconstruction after mastectomy. Nevertheless, breast prosthesis implantation brings a lot of complications, such as: postoperative chronic pain, capsule contracture, prosthesis displacement and prosthesis rupture and infection in severe cases. From the year 1998, botulinum toxin A (BTX-A), a neurotoxin, has been reported to be effective for pain control, capsule contracture lessening, expander enlargement and so on. However, those articles included all kinds of study types: randomized, double-blinded controlled trial (RCT), nonrandomized trial, retrospective analysis and case series, besides the outcomes were varied. To clarify how BTX-A acts at the mammaplasty field, we made this systematic review and meta-analysis.

PURPOSE

To review how BTX-A acts in the field of mammaplasty as well as discuss the relative mechanisms of BTX-A and the related research progress.

METHODS

We searched Pubmed, Embase, Cochrane, Web of science, Clinical trials, Wanfang Database and VIP from inception until March 2018 for papers reporting the use of BTX-A in the breast surgery using implants deep within the pectoralis major muscle. System review, viewpoints and case reports were excluded.

RESULTS

Ten articles met the criteria for inclusion including six prospective controlled (2 RCT; 4 other trails), three retrospective cohorts and one case series. These studies were all about patients using BTX-A during or after breast surgery with expanders or prostheses. A total of 682 patients were enrolled, 543 (79.61%) accepted BTX-A injection, 185 underwent mastectomies with immediate reconstruction, 13 with delayed reconstruction, 295 mastectomies with either immediate or delayed reconstruction and 189 with breast augmentation using silicone prostheses. The study time ranging from 4 months to 13 years, 15 patients (2.76%) received BTX-A injection more than two times, 9.2% received less than 75 U BTX-A, 34.3% 75-100 U, 0.18% 250 U, and in 56.4% the dosage was not stated. No complications associated with BTX-A were mentioned, almost all the studies reported efficacy for pain control. Other assessments included increased speed of expander enlargement and volume were mentioned in four papers, two articles analyzed the visual analogue scores, three suggested relief of capsular contracture, two reported lower narcotic use, three mentioned shorter hospital stays and one proved lowering the rate of unplanned expander. It seems all the studies demonstrate the valid usage of BTX-A, but the quality of this evidence still under the line.

CONCLUSION

We could try to use BTX-A as a new method in the field of mammaplasty. There are so many advantages such as postoperative pain relief, reducing the hospital stay, and increasing operation success rate, but rigorous methodological evidence is still lacking. A lot of studies were retrospective, only two studies used the RCT method. Therefore, to obtain strong evidence to clarify the usage of BTX-A, more randomized double-blinded controlled trials will be required, meanwhile the mechanism study adds to the evidence.

LEVEL OF EVIDENCE III

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A Histological Comparison of Two Human Acellular Dermal Matrix Products in Prosthetic-Based Breast Reconstruction

Background

Acellular dermal matrices (ADMs) are an integral component of breast reconstruction. The ideal matrix would be relatively immuno-inert, allow rapid vascularization, and be affordable. The purpose of this study was to histologically compare 2 commonly used ADM products.

Methods

This is a prospective histological study of 17 patients (20 breasts) following prosthetic-based breast reconstruction with ADM: Alloderm (LifeCell Corp, Branchburg, N.J.) or Cortiva (RTI Surgical, Alachua Fla.). Biopsies were taken from the dermal matrix and natural capsules surrounding the expander/implant during secondary surgery [Range, 72-694 days (mean, 217 days)]. Biopsy specimens were prepared via hematoxylin and eosin, Masson's trichrome, elastin, and transforming growth factor (TGF)-1 stains. Quantitative analysis of staining was performed with ImageJ software. The clinical outcome of each patient is analyzed in relation to capsule architecture and ADM performance.

Results

There were 7 breasts in the Alloderm group and 13 in the Cortiva group. Both groups had similar demographic, aesthetic results, and complication profiles. The TGF-1 staining demonstrated significantly lower levels in the Cortiva capsules (P = 0.0139). The percentage of elastin and collagen are similar in the Cortiva, Alloderm, and natural peri-implant capsules. The native capsules show a significantly greater number of blood vessels when compared with Cortiva and Alloderm (P = 0.0371 and P = 0.0347, respectively); however, there is no difference in vascular pattern between the 2 dermal matrices.

Discussion

Postoperatively, Cortiva demonstrates equal vascularity with less TGF-1 activation compared with Alloderm. The clinical success and complication profile were similar between the Alloderm and Cortiva patients.

Do IL-3/GM-CSF effect on the myofibroblastic differentiation of human adipose derived stromal cells?

BACKGROUND

Capsular contracture is an incurable complication after silicone-based implant surgery. Myofibroblast is the predominant cell in the contracted capsule. We hypothesized that human adipose derive stromal cells (hASCs) together with fibroblast may show a similar phenotypic characteristics of myofibroblast after the treatment of inflammatory cytokines in vitro.

MATERIALS AND METHODS

Interleukin 3 (IL-3) and granulocyte macrophage colony stimulating factor (GM-CSF) were treated in the culture of hASCs and HDFs. Lyn peptide inhibitor was applied as an inhibitor. The changes of cell surface markers (CD105, CD73, CD34, CD45, CD31, CD325 and CD146) were assessed. The expression of various cytokines related to wound contraction were tested such as TGF-β, α-SMA, HGF, FGF, ENT-1, and TSP-1. Myo-D, α-SMA, and glial fibrillary acidic protein (GFAP) were evaluated by blotting and immunocytochemical staining. The collagen-gel contraction assay was performed for the functional contraction of myofibroblastic phenotype.

RESULTS

The expression of α-SMA, Myo-D and GFAP after the treatment of IL-3/GM-CSF showed similar results in hASCs and HDFs. Enhanced expression of TGF- β was observed in HDFs and the increase of ENT-1 and TSP-1 was significant in hASCs. Collagen-gel with HDFs contracted significantly within 24h after the treatment of IL-3/GM-CSF, and the contraction was inhibited by Lyn peptide inhibitor. But in hASCs, the gel-contraction was not significant.

CONCLUSION

IL-3/ GM-CSF effected on the myofibroblastic differentiation of hASCs as well as it did on HDFs. But hASCs did not show the phenotypic gel-contraction within 24h.

Simvastatin Reduces Capsular Fibrosis around Silicone Implants

Capsular fibrosis and contracture occurs in most breast reconstruction patients who undergo radiotherapy, and there is no definitive solution for its prevention. Simvastatin was effective at reducing fibrosis in various models. Peri-implant capsular formation is the result of tissue fibrosis development in irradiated breasts. The purpose of this study was to examine the effect of simvastatin on peri-implant fibrosis in rats. Eighteen male Sprague-Dawley rats were allocated to an experimental group (9 rats, 18 implants) or a control group (9 rats, 18 implants). Two hemispherical silicone implants, 10 mm in diameter, were inserted in subpanniculus pockets in each rat. The next day, 10-Gy of radiation from a clinical accelerator was targeted at the implants. Simvastatin (15 mg/kg/day) was administered by oral gavage in the experimental group, while animals in the control group received water. At 12 weeks post-implantation, peri-implant capsules were harvested and examined histologically and by real-time polymerase chain reaction. The average capsular thickness was 371.2 μm in the simvastatin group and 491.2 μm in the control group. The fibrosis ratio was significantly different, with 32.33% in the simvastatin group and 58.44% in the control group (P < 0.001). Connective tissue growth factor (CTGF) and transforming growth factor (TGF)-β1 gene expression decreased significantly in the simvastatin group compared to the control group (P < 0.001). This study shows that simvastatin reduces radiation-induced capsular fibrosis around silicone implants in rats. This finding offers an alternative therapeutic strategy for reducing capsular fibrosis and contracture after implant-based breast reconstruction.

Human Embryonic Stem Cell-Derived Endothelial Precursor Cell Conditioned Medium Reduces the Thickness of the Capsule Around Silicone Implants in Rats

BACKGROUND

We postulated that the fibrotic capsule around a silicone implant could be induced by ischemic conditions, based on previous reports that hypoxia is an important microenvironmental factor in the development of tissue fibrosis.

OBJECTIVE

This study aimed to determine the effect of human embryonic stem cell (hESC)-derived endothelial precursor cell (EPC) conditioned medium (CM), which has strong angiogenic potential, on the development of capsule around the silicone implant in a rat model.

METHODS AND MATERIALS

Three groups had a mini-silicone implant with a smooth surface inserted. In 2 experimental groups, hESC-EPC CM was administered into the subcutaneous pocket either 1 or 2 times. After 2 months, the capsules were harvested and analyzed by histologic examination.

RESULTS

There was a significant reduction in the thickness of the peri-implant capsules (P < 0.05) between the control and experimental groups. There is no tendency that hESC-EPC CM reduces inflammatory reaction in early postoperative periods. The experimental group showed increased angiogenesis compared to the control group (P < 0.05).

CONCLUSIONS

Tissue hypoxia around the implant may be another cause for the peri-implant capsule. A preventive or therapeutic strategy to decrease capsular contracture by relieving the ischemic condition around the implant can be investigated in the future.

Enhanced Contraction of a Normal Breast-Derived Fibroblast-Populated Three-Dimensional Collagen Lattice via Contracted Capsule Fibroblast-Derived Paracrine Factors: Functional Significance in Capsular Contracture Formation

BACKGROUND

The authors' aim was to identify morphological, genotypic, and cytokine profiles of normal breast-derived fibroblasts, noncontracted breast implant capsule (Baker grades 1 and 2) fibroblasts, and contracted breast implant capsule (Baker grades 3 and 4) fibroblasts, and to investigate the paracrine effects of contracted breast capsule fibroblast--conditioned media on a breast-derived fibroblast-populated three-dimensional collagen lattice.

METHODS

Primary breast-derived fibroblasts (n = 5), noncontracted breast capsule fibroblasts (n = 5), and contracted breast capsule fibroblasts (n = 5) were cultured, and conditioned media were obtained from passage 1 cells. Cells were immunostained for alpha smooth muscle actin to identify myofibroblasts. A panel of 16 inflammatory, fibrosis, extracellular matrix, and tissue remodeling-related genes were investigated using quantitative reverse transcriptase polymerase chain reaction and cytokine arrays. Fibroblast-populated collagen lattices were fabricated and treated with conditioned media, and lattice contracture was measured over 5 days.

RESULTS

Several inflammatory and fibrotic genes were significantly dysregulated in contracted breast capsule fibroblasts compared with noncontracted breast capsule fibroblasts and breast-derived fibroblasts (p < 0.05). Breast-derived fibroblast-populated collagen lattices treated with contracted breast capsule fibroblast-conditioned media demonstrated increased lattice contraction compared with treatment with normal 10% serum media (control), breast-derived fibroblasts, or noncontracted breast capsule fibroblast-conditioned media (p < 0.05). Breast-derived fibroblasts supplemented with contracted breast capsule fibroblast-conditioned media transformed into a contracted breast capsule fibroblast-like cell (p < 0.05).

CONCLUSION

The authors show that contracted breast capsule-derived fibroblasts induce normal breast fibroblast transformation and contraction via paracrine signaling, which may contribute to capsular contracture formation.

Biomedical implant capsule formation: lessons learned and the road ahead

Clinicians and investigators have been implanting biomedical devices into patients and experimental animals for centuries. There is a characteristic complex inflammatory response to the presence of the biomedical device with diverse cell signaling, followed by migration of fibroblasts to the implant surface and the eventual walling off of the implant in a collagen capsule. If the device is to interact with the surrounding tissues, the collagen envelope will eventually incapacitate the device or myofibroblasts can cause capsular contracture with resulting distortion, migration, or firmness. This review analyzes the various tactics used in the past to modify or control capsule formation with suggestions for future investigative approaches.

The preventive effect of topical zafirlukast instillation for peri-implant capsule formation in rabbits

Background

Capsular contracture is the most troublesome complication in breast implant surgery. Although capsule formation can be seen as a normal reaction to a foreign body, it can induce pain, hardness, deformity, and other pathologic problems. Surgical intervention is required in severe cases, but even surgery cannot guarantee a successful outcome without recurrence. This experimental study confirms that single topical administration of leukotriene antagonist zafirlukast (Accolate, Astrazeneca) reduces peri-implant capsule formation and prevents capsular contracture.

Methods

Twelve smooth-surfaced cohesive gel implants were implanted in New Zealand White rabbits. These miniature implants were designed to be identical to currently used products for breast augmentation. The rabbits were divided into 2 groups. In the experimental group (n=6), the implant and normal saline with zafirlukast were inserted in the submuscular pocket. In the control group (n=6), the implant and normal saline alone were used. Two months later, the implants with peri-implant capsule were excised. We evaluated capsule thickness and collagen pattern and performed immunohistochemical staining of myofibroblasts, transforming growth factor (TGF)-β1, 2.

Results

The thickness of the capsules in the experimental group was reduced in both dorsal and ventral directions. The collagen pattern showed parallel alignment with low density, and the number of myofibroblasts as well as the amounts of TGF-β1 and TGF-β2 were reduced in the experimental group.

Conclusions

We suggest that single topical administration of leukotriene antagonist zafirlukast can be helpful in reducing capsule formation and preventing capsular contracture via myofibroblast suppression, modulation of fibroblastic cytokines, and anti-inflammatory effect.

Development and functional evaluation of biomimetic silicone surfaces with hierarchical micro/nano-topographical features demonstrates favourable in vitro foreign body response of breast-derived fibroblasts

Reproducing extracellular matrix topographical cues, such as those present within acellular dermal matrix (ADM), in synthetic implant surfaces, may augment cellular responses, independent of surface chemistry. This could lead to enhanced implant integration and performance while reducing complications. In this work, the hierarchical micro and nanoscale features of ADM were accurately and reproducibly replicated in polydimethylsiloxane (PDMS), using an innovative maskless 3D grayscale fabrication process not previously reported. Human breast derived fibroblasts (n=5) were cultured on PDMS surfaces and compared to commercially available smooth and textured silicone implant surfaces, for up to one week. Cell attachment, proliferation and cytotoxicity, in addition to immunofluorescence staining, SEM imaging, qRT-PCR and cytokine array were performed. ADM PDMS surfaces promoted cell adhesion, proliferation and survival (p=<0.05), in addition to increased focal contact formation and spread fibroblast morphology when compared to commercially available implant surfaces. PCNA, vinculin and collagen 1 were up-regulated in fibroblasts on biomimetic surfaces while IL8, TNFα, TGFβ1 and HSP60 were down-regulated (p=<0.05). A reduced inflammatory cytokine response was also observed (p=<0.05). This study represents a novel approach to the development of functionalised biomimetic prosthetic implant surfaces which were demonstrated to significantly attenuate the acute in vitro foreign body reaction to silicone.

Capsular contraction with s-shaped deformity of nonlength-expanding inflatable penile prosthesis cylinders: management and prevention strategies

Introduction

Capsular contraction (CC) occurring with inflatable penile prosthesis (IPP) reservoirs has been reported by urologists as a cause of autoinflation. The concept of CC occurring around IPP cylinders has not been studied.

Aims

Herein we report a case of CC occurring with nonlength-expanding IPP cylinders, resulting in an S-shaped deformity.

Main Outcome Measures

We sought to report a novel cause of S-shaped deformity in patients after IPP surgery.

Methods

We reviewed a recent clinical case and conducted a literature review on capsular scar formation in prosthetic surgery. We also conducted a literature review of the inflammatory cascade related with prosthetic surgery.

Results

Capsular contracture of nonlength-expanding cylinders resulting in S-shaped deformity has not been previously reported. The role of certain inflammatory markers seems to play a common role of capsular contracture in the penis and other prosthetic implantation sites.

Conclusions

Capsular contractures around the cylinders of an IPP can cause deformity, even in patients who have appropriately sized, nonlength-expanding cylinders. A better understanding is needed regarding the mechanical properties of the tunica albuginea and the inflammatory cascade associated with penile implant surgery. This case represents an argument for early and aggressive postoperative inflation of the IPP. Future studies should evaluate the role of inflammation modulators as adjuvant therapy after IPP surgery. Karpman E and Henry G. Capsular contraction with S-shaped deformity of nonlength-expanding inflatable penile prosthesis cylinders: Management and prevention strategies. Sex Med 2013;1:95–98.

Mast cells in the periprosthetic breast capsule

BACKGROUND

Symptomatic capsular contracture occurs in about 10 % of primary breast augmentations and in more than double that rate in reconstruction after mastectomy, especially in the setting of radiation. Mast cells, traditionally associated with immune response and inflammation, secrete profibrotic mediators and may play a role in capsule formation and contracture. We analyzed the mast cell and fibroblast populations in breast capsule tissue from patients who underwent capsular excision.

METHODS

Capsule tissue was collected from patients who underwent exchange of tissue expanders for permanent implants, revision of reconstruction, or revision augmentation. Breast capsule tissues were prepared for histological analyses of mast cells, fibroblasts, and collagen. Mast cells and fibroblasts were isolated from capsule tissue and screened for mediators and receptor expression.

RESULTS

In breast capsule tissue, the average numbers of mast cells and fibroblasts were 9 ± 1/mm(2) and 33 ± 10/mm(2), respectively. There were significantly more mast cells on the posterior side than on the anterior side of the capsule tissue (12 ± 2 vs. 6 ± 1/mm(2), p < 0.01). Baker grade IV capsules had an increased number of fibroblasts compared to Baker grade I capsules (93 ± 9 vs. 40 ± 19/mm(2), p < 0.001). In breast capsule tissue, mast cells contained renin, histamine, and TGF-β, and their respective receptors, AT1R, H1R, and TGF-βRI were expressed by fibroblasts.

CONCLUSION

These data indicate that within breast capsule tissue mast cells contain mediators that may activate neighboring fibroblasts. Understanding the role of mast cells in pathologic periprosthetic breast capsule formation may lead to novel therapies to prevent and treat capsular contracture.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266.

Oestrogen receptor-alpha and -beta expression in breast implant capsules: experimental findings and clinical correlates

Myofibroblasts provide a force to decrease the surface area of breast implant capsules as the collagen matrix matures. 17-β-Oestradiol promotes myofibroblast differentiation and contraction. The aim of the study was to investigate the expression of oestrogen receptors α and β in capsular tissue. The study enrolled 70 women (80 capsules) who underwent expander or implant removal, following breast reconstruction. Specimens were stained with haematoxylin/eosin, Masson trichrome and immunohistochemistry and immunofluorescence stainings for alpha-smooth muscle actin (α-SMA), oestrogen receptor-alpha (ER-α) and oestrogen receptor-beta (ER-β). The relationship between anti-oestrogenic therapy and capsular severity was evaluated. A retrospective analysis of 233 cases of breast reconstruction was conducted. Myofibroblasts expressed ER-α, ER-β or both. In the whole sample, α-SMA score positively correlated with ER-α (p = 0.022) and ER-β expression (p < 0.004). ER-β expression negatively correlated with capsular thickness (p < 0.019). In capsules surrounding expanders α-SMA and ER-α, expressions negatively correlated with time from implantation (p = 0.002 and p = 0.016, respectively). The incidence of grade III-IV contracture was higher in patients who did not have anti-oestrogenic therapy (p < 0.036); retrospective analysis of 233 cases confirmed this finding (p < 0.0001). This study demonstrates the expression of oestrogen receptors in myofibroblasts of capsular tissue. A lower contracture severity was found in patients who underwent anti-oestrogenic therapy.

Identification of molecular phenotypic descriptors of breast capsular contracture formation using informatics analysis of the whole genome transcriptome

Breast capsular contracture formation following silicone implant augmentation/reconstruction is a common complication that remains poorly understood. The aim of this study was to identify potential biomarkers implicated in breast capsular contracture formation by using, for the first time, whole genome arrays. Biopsy samples were taken from 18 patients (23 breast capsules) with Baker Grade I-II (Control) and Baker Grade III-IV (Contracted). Whole genome microarrays were performed and six significantly dysregulated genes were selected for further validation with quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. Hematoxylin and eosin was also carried out to compare the histological characteristics of control and contracted samples. Microarray results showed that aggrecan, tissue inhibitor of metalloproteinase 4 (TIMP4), and tumor necrosis factor superfamily (ligand) member 11 were significantly down-regulated in contracted capsules; while matrix metallopeptidase 12, serum amyloid A 1, and interleukin 8 (IL8) were significantly up-regulated. The dysregulation of aggrecan, tumor necrosis factor superfamily (ligand) member 11, TIMP4, and IL8 was validated by quantitative reverse transcriptase polymerase chain reaction (p < 0.05). Immunohistochemistry confirmed an increased protein expression for IL8 and matrix metallopeptidase 12 in contracted capsules (p < 0.05), and decreased protein expression of TIMP4 (p < 0.05). This study has shown, for the first time, a number of unique biomarkers of significance in capsular contracture formation. IL8 and TIMP4 may serve as potential key diagnostic, therapeutic, and prognostic biomarkers in capsular contracture formation.

Effects of zafirlukast on capsular contracture: long-term results

Capsular contracture is a distressing complication after breast augmentation for both the patient and surgeon. Although capsular contracture is a multifactorial process, one common denominator in the successful treatment of this complication is believed to be the abatement of inflammation. Leukotriene antagonists have recently emerged as effective prophylactic agents in reactive airway diseases. A prospective study was carried out on 60 female patients (120 prostheses implanted) with mild/severe capsular contracture in at least one breast. The hardness of capsular contracture was assessed by means of the mammary compliance method. Patients received zafirlukast (Accolate&#174;) for a 6-month period. Mammary compliance was assessed at the start of the study and thereafter monthly, during drug intake and for one year after drug withdrawal. The results show a significant decrease in breast compliance values in the first 6 months, followed by a significant increase one year after the end of drug intake. Indeed, zafirlukast-treated patients displayed a 6.93 percent reduction in mammary compliance after 1 month, 14.42 percent after 3 months, 22.05 percent after 6 months and 22.52 percent after 7 months (1 month after the withdrawal of the drug). Thereafter, mammary compliance values gradually increased. A 5.47 percent reduction in mammary compliance was observed 1 year after drug withdrawal. The present study suggests that zafirlukast may be effective in reducing breast capsule distortion in patients with long-standing contracture, though reduced capsular contracture values are strictly related to the duration of drug intake.

The periprosthetic capsule and connective tissue diseases: a piece in the puzzle of autoimmune/autoinflammatory syndrome induced by adjuvants

Breast prostheses have been criticized for being responsible for triggering systemic autoimmune disease. The presence of breast implants causes a natural foreign body reaction characterized by the infiltration of macrophages and T-cells. Using PubMed, Medline and eMedicine, we performed a systematic literature review on the stages of periprosthetic capsule formation and cells involved in order to understand which immunological pathways could be responsible for giving rise to, and the development of, connective tissue disease such as systemic sclerosis. We focused on the relationship between tissue growth factor- β, interleukin (IL)-1, IL-6 and T helper 17 or T regulatory cells, as well as on their effects on the different steps of capsular tissue formation. A disturbance in the modulation of these key cytokines may be responsible, in susceptible individuals, for a perpetuation of the inflammatory reaction which can locally lead to capsular contracture and at the systemic level may contribute to triggering autoimmune diseases.

The effect of Zafirlukast on capsule formation in post-radiation silicone implants

Currently, breast cancer represents the most common indication for mastectomy with negative influence on personal perception, sexuality and partnership. Since the introduction of breast implants, silicone, and saline breast implantation have become one of the most common procedures performed by plastic surgeons, not only for aesthetic reasons but also for reconstructive purposes. These women will ultimately be faced with the prospect of capsular contracture. This is especially true in patients receiving radiation therapy, where irradiation increases the risk of complications, capsular contracture and may compromise a favorable aesthetic result. Despite the capsular contracture is the most common complication for both aesthetic and reconstructive breast surgery, the treatment have remained unsolved. Leukotriene antagonists (LTRAs) have emerged as effective prophylactic agents in the management of reactive airway diseases, and recently they have used as an off label prophylactic agent against the capsular contracture after breast augmentation. However up to now there is no any experimental research or clinical study in the medical literature about the effect of Zafirlukast on the capsular formation around irradiated silicone implants.

Effects of coagulase-negative staphylococci and fibrin on breast capsule formation in a rabbit model

BACKGROUND

The etiology and ideal clinical treatment of capsular contracture (CC) remain unresolved. Bacteria, especially coagulase-negative staphylococci, have been previously shown to accelerate the onset of CC. The role of fibrin in capsule formation has also been controversial.

OBJECTIVE

The authors investigate whether fibrin and coagulase-negative staphylococci (CoNS) modulate the histological, microbiological, and clinical outcomes of breast implant capsule formation in a rabbit model and evaluate contamination during the surgical procedure.

METHODS

Thirty-one New Zealand white female rabbits were each implanted with one tissue expander and two breast implants. The rabbits received (1) untreated implants and expanders (control; n = 10), (2) two implants sprayed with 2 mL of fibrin and one expander sprayed with 0.5 mL of fibrin (fibrin; n = 11), or (3) two implants inoculated with 100 µL of a CoNS suspension (10(8)CFU/mL-0.5 density on the McFarland scale) and one expander inoculated with a CoNS suspension of 2.5 × 10(7) CFU/mL (CoNS; n = 10). Pressure/volume curves and histological and microbiological evaluations were performed. Operating room air samples and contact skin samples were collected for microbiological evaluation. The rabbits were euthanized at four weeks.

RESULTS

In the fibrin group, significantly decreased intracapsular pressures, thinner capsules, loose/dense (<25%) connective tissue, and negative/mild angiogenesis were observed. In the CoNS group, increased capsular thicknesses and polymorph-type inflammatory cells were the most common findings. Similar bacteria in capsules, implants, and skin were cultured from all the study groups. One Baker grade IV contracture was observed in an implant infected with Micrococcus spp.

CONCLUSIONS

Fibrin was associated with reduced capsule formation in this preclinical animal model, which makes fibrin an attractive potential therapeutic agent in women undergoing breast augmentation procedures. Clinical strategies for preventing bacterial contamination during surgery are crucial, as low pathogenic agents may promote CC.

A review of the foreign-body response to subcutaneously-implanted devices: the role of macrophages and cytokines in biofouling and fibrosis

The biological response to implanted biomaterials in mammals is a complex series of events that involves many biochemical pathways. Shortly after implantation, fibrinogen and other proteins bind to the device surface, a process known as biofouling. Macrophages then bind to receptors on the proteins, join into multinucleated giant cells, and release transforming growth factor beta and other inflammatory cytokines. In response to these signals, quiescent fibroblasts are transformed into myofibroblasts, which synthesize procollagen via activation of Smad mediators. The procollagen becomes crosslinked after secretion into the extracellular space. Mature crosslinked collagen and other extracellular matrix proteins gradually contribute to formation of a hypocellular dense fibrous capsule that becomes impermeable or hypopermeable to many compounds. Porous substrates and angiogenic growth factors can stimulate formation of microvessels, which to some extent can maintain analyte delivery to implanted sensors. However, stimulation by vascular endothelial growth factor alone may lead to formation of leaky, thin-walled, immature vessels. Other growth factors are most probably needed to act upon these immature structures to create more robust vessels.During implantation of foreign bodies, the foreign-body response is difficult to overcome, and thousands of biomaterials have been tested. Biomimicry (i.e., creating membranes whose chemical structure mimics natural cellular compounds) may diminish the response, but as of this writing, it has not been possible to create a stealth material that circumvents the ability of the mammalian surveillance systems to distinguish foreign from self.

Flector tissugel used to treat capsular contracture after breast augmentation surgery

Capsular contracture constitutes the main postoperative complication after breast augmentation by implant placement. To date, no systemic treatment known allows for improvement that does not simultaneously put the patient at risk for secondary complications of a more general nature. Flector Tissugel is the sole locally active antiinflammatory patch. Its durable local antiinflammatory effect is associated only with a risk for rare and highly limited side effects. After approximately 3 weeks of treatment, a high frequency of change from capsular contracture Baker 2 or 3 to Baker 1 occurs, provided the application was started no later than 3 months after the onset of capsular contracture.

Pirfenidone prevents capsular contracture after mammary implantation

BACKGROUND

Pirfenidone (PFD), a new antifibrotic and antiinflammatory agent, prevents and resolves fibrous tissue. This study evaluated the effect of PFD on adverse events in mammary implants using an animal model. Mammary implantation, the most frequent aesthetic surgery, may present several complications after surgery such as swelling, capsule contracture, hardness, and pain.

METHODS

Wistar rats underwent submammary implantation with either smooth or textured silicone gel implants and were administrated 200 mg/kg of PFD daily. The control group received saline. The animals were killed at 8 weeks. The capsular tissue of both implants was removed for histologic and molecular analyses.

RESULTS

Typical postaugmentation periimplant capsules with opacity on adjacent tissues developed 8 weeks after silicone implantation. No significant differences were observed between the textured and smooth implants in any analyzed parameter. Clearly, PFD reduced capsule thickness around submmamary tissue, fibroblast-like cell proliferation, and recruitment of inflammatory cells. The total cell numbers per field were reduced as well. In contrast, the control group presented abundant mononuclear cell infiltration and fibroblast-like cell proliferation. The total content of collagen in the PFD group was 50% less than in the control group. Fibroblast cells displayed 45% less activated phenotype in the PFD group than in the control group, as determined by immunohistochemistry techniques. In the PFD animals, transforming growth factor-beta (TGF-beta) decreased 85% and collagen 1 gene expression 60%, compared with the control group.

CONCLUSION

The findings show a positive effect of PFD on mammary contracture in 10 rats. Despite the small number of animals, the differences found in 10 control rats encourage the authors to propose a larger study later and to suggest PFD as a potential preventive strategy in human mammary implantation surgery.

Clinical and Morphological Conditions in Capsular Contracture Formed around Silicone Breast Implants

BACKGROUND

A study was performed to investigate histological changes in capsules formed around silicone breast implants and their correlation with the clinical classification of capsular contracture defined by the Baker score. For histological classification, the authors used the classification introduced by Wilflingseder, which identifies four grades of contracture.

METHODS

The study included 24 female patients (average age, 40 +/- 12 years) with capsular contracture after bilateral cosmetic breast augmentation with smooth silicone gel implants (Mentor, Santa Barbara, Calif.). The Baker score was determined preoperatively for each patient. Samples of capsular tissue were obtained from all patients for histologic and immunohistochemical analyses. Capsular thickness, age of the collagen fibers, presence of synovia-like metaplasia on the inner surface of the capsule, number of histiocytes, giant cells, and other inflammatory cells, amount of silicone, foreign body granulomas, and capsule calcification were evaluated.

RESULTS

There was a positive correlation between capsular thickness (p < 0.05) and Baker score. Silicone-containing deposits were found in all four histological capsule types. A trend toward greater capsular thickness was documented in patients with severe inflammatory reaction. These patients also had more clinical symptoms. Greater capsular thickness was associated with a higher number of silicone particles and silicone-loaded macrophages in the peri-implant capsule.

CONCLUSIONS

The authors demonstrated a positive correlation (p < 0.05) between the clinical classification (Baker score I to IV) and the histological classification introduced by Wilflingseder (Wilflingseder score I to IV). An exact histological classification is needed to describe precisely the morphological changes in capsular contracture.

Down-regulating causes of fibrosis with tamoxifen: a possible cellular/molecular approach to treat rhinophyma

Fibrosis and proliferative scarring are prominent features of the severe forms of rhinophyma. Up-regulation of growth and fibroblast kinetics are hallmarks of fibrosis. Persistent overexpression or dysregulated activation of the fibrogenic isoforms of transforming growth factor beta (TGF-beta) is associated with the increased fibroblast function leading to fibrotic conditions such as rhinophyma. Tamoxifen, a synthetic nonsteroidal antiestrogen, can neutralize or down-regulate TGF-beta. Fibroblast-populated collagen lattices (FPCLs) were constructed from fibroblasts cultured from rhinophyma or normal nasal skin. One-half of each set of FPCLs was treated with Tamoxifen. Lattice contraction was serially measured over 5 days, and the supernatants of the cultures were analyzed for TGF-beta-2 by immunoassay. Tamoxifen significantly decreased fibroblast activity by decreasing contraction of the treated lattices (P < 0.05) and significantly decreased the production/secretion of TGF-beta-2 by rhinophyma fibroblasts (P < 0.001). These results suggest a possible new cellular/molecular approach to the treatment of the fibrotic varieties of rhinophyma.

Cellular and Molecular Dynamics in the Foreign Body Reaction

Intracorporally implanted materials, such as medical devices, will provoke the body to initiate an inflammatory reaction. This inflammatory reaction to implanted materials is known as the foreign body reaction (FBR) and is characterized by 3 distinct phases: onset, progression, and resolution. The FBR proceeds in the creation of a dynamic microenvironment that is spatially well organized. The progression of the FBR is regulated by soluble mediators, such as cytokines, chemokines, and matrix metalloproteinases (MMPs), which are produced locally by tissue cells and infiltrated inflammatory cells. These soluble mediators orchestrate the cascade of cellular processes in the microenvironment that accompanies the FBR, consisting of cellular activation, angiogenesis, extravasation, migration, phagocytosis, and, finally, fibrosis. The nature of the FBR requires that the soluble mediators act in a spatial and temporally regulated manner as well. This regulation is well known for several inflammatory processes, but scarce knowledge exists about the intricate relationship between the FBR and the expression of soluble mediators. This review discusses the key processes during the initiation, progression, and resolution phase, with emphasis on the role of soluble mediators. Besides other sites of implantation, we focus on the subcutaneous implantation model.

Use of the Transforming Growth Factor-??1 Inhibitor Peptide in Periprosthetic Capsular Fibrosis: Experimental Model with Tetraglycerol Dipalmitate

BACKGROUND

Capsular contracture is the most common specific complication associated with silicone prostheses. It is thought to be caused by the gradual retraction of the fibrous scar tissue that forms around the prosthesis. Molecular biology has made it possible to determine the role of transforming growth factor beta (TGF-beta) in the scar physiopathology of any fibrotic process, including periprosthetic capsular fibrosis. The effects on the inhibition of TGF-beta have also been demonstrated in experimental models of scar formation and fibrosis, which opens the way for new therapeutic alternatives in the treatment of capsular contracture.

METHODS

Three experimental groups of 10 rats each were formed to evaluate periprosthetic fibrosis after its modulation with a newly synthesized TGF-beta1 peptide inhibitor in a tetraglycerol dipalmitate matrix. In the first group, subcutaneously and submuscularly placed, smooth, solid silicone prostheses were left untreated; in the second group, the prostheses were left after being immersed in a solution of tetraglycerol dipalmitate; and in the third group, following the same protocol as in the second group, the solution contained tetra-glycerol dipalmitate mixed with the inhibitor peptide of TGF-beta1. The animals were euthanized 8 weeks after implantation, and the capsules were assessed both macroscopically and histologically.

RESULTS

Inhibition of capsular thickness and cellularity was significantly more effective in the group of animals treated with the inhibitor peptide of TGF-beta1.

CONCLUSIONS

The TGF-beta1 inhibitor peptide applied in a matrix with tetraglycerol dipalmitate is significantly effective in achieving a reduction in periprosthetic fibrosis after placement of silicone implants, either subcutaneously or submuscularly. This result suggests new therapeutic approaches.

The effect of seprafilm and interceed on capsule formation around silicone discs in a rat model

The insertion of a foreign substance, such as a breast implant into mammalian soft tissues, evokes a wound healing response that culminates in a dense connective-tissue envelope or capsule surrounding the implant. Several biodegradable products, such as Seprafilm (carboxymethylcellulose and hyaluronic acid) and Interceed (oxidized regenerated cellulose), have been demonstrated to inhibit adhesions in abdominal and gynecologic surgery. The ability of these cellulose compounds to inhibit capsule formation was addressed in this investigation. Twenty-eight rats were implanted intermuscularly with either plain silicone discs (10 animals), discs wrapped in Seprafilm (10 animals), or discs covered with Interceed (8 animals). Additional control animals (6 animals) consisted of two that had sham operations, two animals implanted with Seprafilm only, and two more implanted with Interceed only. Animals were sacrificed in pairs at varying time intervals after implantation (2, 4, 8, 12, and 16 wk), and the tissues around the silicone discs were analyzed with light microscopy. Control animals were sacrificed at 8 wk. Both Interceed and Seprafilm slowed the formation of a capsule around the implanted silicone discs as both products were degraded. Evidence of residual material, presumably Seprafilm and Interceed, was seen intracellularly in animals 3 to 4 mo, respectively, after implantation. However, neither material prevented the eventual formation of a fibrous capsule around the silicone discs. The results of this study suggest that encapsulating foreign substances with these types of biodegradable materials will not significantly hinder capsule formation. A more direct attack on the wound healing mechanism may provide a definitive solution for capsule problems with implanted materials.

Mineralization followup with the use of NMR spectroscopy and others

High-resolution solid state NMR spectroscopy appears to be a powerful method for a better understanding of bone structures and bone substitutes and implants. It is particularly efficient to estimate osteoformation via bioceramic bone colonization. Pathological calcification occurring in bioprosthetic heart valves and breast prostheses can be characterized as a complement to X-ray spectrometry.

Proliferative scarring

Proliferative scarring in all organ systems is an enigma. Treatment has been difficult to impossible because the pathobiology of exuberant scarring and fibrosis was unclear. With the concept that proliferative scarring can be viewed on the healing trajectory and dissected into variations of the normal wound healing cellular processes mediated by soluble cytokine messengers, one can begin to understand how excessive scar formation occurs. Realizing that overexpression or dysregulated activity of the fibrogenic isoforms of TGF-beta and its attendant effect on apoptosis may be responsible for proliferative scarring opens the route to propose rational molecular manipulations that can be tested for the prevention or treatment of this enigmatic condition.

Role of connective tissue growth factor in breast implant elastomer capsular formation

Transforming growth factor-beta (TGF-beta) has been demonstrated to be a mediator in scar formation and in multiple fibrotic disorders such as in Dupuytren contractures and in pulmonary fibrosis. Recently, it has been demonstrated that connective tissue growth factor (CTGF) is a downstream mediator of TGF-beta and acts to stimulate wound contraction and fibrosis. The purpose of this study is to assess the role of CTGF in the development of breast implant elastomer capsule formation over time and to evaluate the effects of TGF-beta and CTGF antisense (AS) oligonucleotides on capsule formation. Fifteen Sprague-Dawley rats were randomly assigned to treatment (n = 12) and control (n = 3) groups. Four 2- x 2-cm pockets were created on the dorsum deep to the panniculus carnosus in each rat. A 1- x 1-cm smooth breast implant elastomer was placed. Each rat in the treatment group received 1 ml vehicle, AS-TGF-beta, AS-CTGF, or scramble antisense oligonucleotide (AS-scramble). Control rats received either 1 ml vehicle or 1 ml saline in each pocket. At weeks 1, 3, and 5, four treatment rats and one control rat were randomly selected and killed. Tissue blocks were harvested for determination of CTGF levels using the enzyme-linked immunosorbent assay technique and for hematoxylin and eosin slides to evaluate capsule formation. Levels of CTGF in capsular tissue treated with vehicle or AS-scrambled were similar and progressively increased in tissues on weeks 1, 3, and 5, compared with normal skin. At weeks 1 and 3 after surgery, levels of CTGF were suppressed in capsules treated with AS-CTGF or AS-TGF-beta compared with normal skin and with tissues treated with vehicle or AS-scramble (p = 0.002). At week 5, levels of CTGF were similar to levels in normal skin. Histological analysis revealed reduced capsular formation in samples treated with AS-CTGF or AS-TGF-beta compared with the two other treated sites. In conclusion, a single and local treatment with AS-CTGF or AS-TGF-beta at the time of surgery reduced CTGF levels in tissue and correlated with reduced capsular formation in a rat model. These data suggest a new therapeutic strategy to reduce early capsular formation based on local application of antisense oligonucleotides targeting CTFG and TGF-beta.

Further evidence for the role of fibrosis in the pathobiology of rhinophyma

Recent evidence suggests that fibrosis may play an important role in the pathobiology of rhinophyma. The fibrogenic cytokine transforming growth factor (TGF)-beta2 has been reported to be up-regulated in rhinophyma tissue. Of the three common isoforms of TGF-beta, TGF-beta1 and TGF-beta2 are considered fibrogenic, whereas TGF-beta3 has antiscarring properties. To provide further evidence for the role of fibrosis in the pathobiology of rhinophyma, specimens from 8 patients with rhinophyma were compared with nine specimens of normal nasal skin. Immunohistochemistry was used to compare intensity levels of TGFbeta1 and TGFbeta3 proteins, and quantitative reverse transcription-polymerase chain reaction was used to determine messenger ribonucleic acid (mRNA) expression levels of TGFbeta1 and TGFbeta3. TGF-beta1 was elevated significantly in rhinophyma tissue (p < 0.001), whereas TGF-beta3 was no different in the rhinophyma specimens compared with normal nasal skin (p = 0.06). TGFbeta1 mRNA expression was five-fold higher in rhinophyma tissue compared with normal skin (p < 0.001). The mRNA expression of TGF-beta3 was the same for both pathological and normal tissue (p < 0.09). These data, together with previously published observations, present further evidence that fibrosis mediated by the fibrogenic cytokines TGFbeta1 and TGFbeta2 play a role in the pathobiology of rhinophyma and suggest a means of treatment by neutralizing or down-regulating these cytokines.

Tamoxifen decreases fibroblast function and downregulates TGF(beta2) in dupuytren's affected palmar fascia

BACKGROUND

Dupuytren's contracture is a fibroproliferative disorder that is associated with increased collagen deposition. Isoforms of transforming growth factor beta (TGF(beta)), normally TGF(beta1) and TGF(beta2), are involved in the progressive fibrosis of Dupuytren's disease. It has been suggested that downregulation of TGF(beta) may be useful in the treatment of the condition. Tamoxifen, a synthetic nonsteroidal antiestrogen, is known to modulate the production of TGF(beta). This study examined the role of tamoxifen in decreasing fibroblast function and downregulating TGF(beta2).

METHODS

Primary cultures of fibroblasts were obtained from Dupuytren's affected fascia and carpal tunnel affected fascia as a control. Collagen lattices were prepared and populated with the fibroblasts. The fibroblast-populated collagen lattices (FPCL) were then measured for contraction every 24 h for 5 days. Supernatant was obtained from the culture medium following completion of the FPCL portion of the experiment and used for a TGF(beta2) immunoassay.

RESULTS

Dupuytren's affected fibroblasts contracted the FPCLs significantly more than carpal tunnel control fibroblasts. Treating the fibroblasts with tamoxifen caused a decreased contraction rate in both Dupuytren's affected fibroblasts and carpal tunnel controls. There was increased TGF(beta2) expression in the Dupuytren's affected fascia group compared to the carpal tunnel control group. Tamoxifen decreased TGF(beta2) expression in Dupuytren's affected fascia group but not in the carpal tunnel control group.

CONCLUSION

TGF(beta) appears to be the key cytokine in the fibrogenic nature of Dupuytren's disease. Tamoxifen treatment has been demonstrated to decrease the function of fibroblasts derived from Dupuytren's affected fascia and downregulated TGF(beta2) production in these same fibroblasts. These data suggest a method to manipulate and control Dupuytren's contracture in the clinical setting.

Expression of cyclooxygenase-2 in the periprosthetic capsule surrounding a silicone shell implant in the rat

Prosthetic breast implants are used frequently for both aesthetic and reconstructive purposes. Histologically, the normal tissue response to silicone implants typically involves an inflammatory infiltrate that consists initially of macrophages, and later consists of fibroblasts, myofibroblasts, and lymphocytes. To characterize further the nature of the inflammatory response to silicone breast implants, the authors evaluated the expression of the enzyme cyclooxygenase-2 (COX-2) by the tissues and cells of the breast capsule after silicone augmentation in an animal model. COX-2 is an inducible enzyme that is expressed primarily in response to inflammatory stimuli and mediates the production of prostaglandins that support the inflammatory process. Fifty-nine animals at five time points were evaluated. Specifically, on days 4, 7, 14, 28, and 80 the authors identified cytoplasmic COX-2 expression in each of the three cell types of interest, including endothelial cells, macrophages, and fibroblasts. Selective COX-2 inhibiting agents may be an appropriate pharmacological intervention for modulating the formation of periprosthetic capsules.