Breast Tissue Engineering Research Articles

Synthesis and characterization of a silk fibroin/placenta matrix hydrogel for breast reconstruction

Reconstructive surgery is a complex and demanding interdisciplinary field. One of the major challenges is the production of sizeable, implantable, inexpensive bioprostheses such as breast implants. In this study, porous hybrid hydrogels were fabricated by a combinatorial method using decellularized human placenta (dHplacenta) and silk fibroin. Histology was used to confirm the acellularity of the dHplacenta. The physio-chemical properties of the hydrogels were evaluated using SEM, FTIR, and rheological assays. The synthesized hydrogels exhibited a uniform 3-D microstructure with an interconnected porous network, and the hybrid hydrogels with a 30/70 ratio had improved mechanical properties compared to the other hydrogels. Hybrid hydrogels were also cultured with adipose-derived mesenchymal stem cells (ADSCs). Liposuction was used to obtain adipose tissue from patients, which was then characterized using flow cytometry and karyotyping. The results showed that CD34 and CD31 were downregulated, whereas CD105 and CD90 were upregulated in ADSCs, indicating a phenotype resembling to that of mesenchymal stem cells from the human bone marrow. Moreover, after re-cellularized hydrogel, the live/dead assay and SEM analysis confirmed that most viability and cellular expansion on the hydrogels contained higher ratios of dHplacenta (30/70) than the other two groups. All these findings recapitulated that the 30/70 dHplacenta/silk fibroin hydrogel can perform as an excellent substrate for breast tissue engineering applications.

Scaffold-guide breast tissue engineering: the future of breast implants

In this editorial the authors argue that a fresh approach to breast implant manufacture and materials is warranted.

Modeling and simulation of smart magnetic self-assembled nanomicelle trajectories in an internal thoracic artery flow for breast cancer therapy.

Magnetic drug targeting (MDT) is one of the most modern techniques in cancer therapy for its ability to reduce the side effects of chemotherapy experienced by systemic drug administration. In this study, a comprehensive mathematical model has been developed to predict the drug particle trajectories of anticancer dasatinib magnetic nanomicelles (DAS-MNM) released in an internal thoracic artery (ITA) blood flow for breast cancer therapy using an external magnetic field. Several factors are investigated in regard to the efficiency of MDT through the ITA, including magnetic field strength (MFS), relative magnetic permeability, magnet size, drug particle size, and initial position of drug particle. The drug particle trajectory results confirmed the successful MDT using an external magnetic field with a capture efficiency of more than 90%. This was achieved by employing a wide range of particle sizes of DAS-MNM close to the external magnetic field source at the arterial wall than in other positions. Moreover, the results showed that the number of trapped particles increased with increasing both MFS and drug particle diameter within the target tissue, while the drug particle permeability did not have a considerable effect on the particle retention. In addition, for achieving a successful drug/cargo delivery through the arteries, the magnetic field, the particle size, and the initial release locations should be adjusted simultaneously. The present work offers insights into the critical factors in MDT with a significant impact on breast cancer therapy, tissue engineering, and regenerative medicine. Magnetic drug targeting model of anticancer dasatinib magnetic nanomicelles (DAS-MNM) released in an internal thoracic artery blood flow for breast cancer therapy.

Additively manufactured macroporous chambers facilitate large volume soft tissue regeneration from adipose-derived extracellular matrix

Breast tissue engineering is a promising alternative intervention for breast reconstruction. Due to their low immunogenicity and well-preserved adipogenic microenvironment, decellularized adipose tissue (DAT) can potentially regenerate adipose tissue in vivo. However, the volume of adipose tissue regenerated from DAT can hardly satisfy the demand for breast reconstruction. Tissue engineering chamber (TEC) is an effective technique for generation of large adipose tissue volumes. However, TEC applications necessitate reoperation to remove non-degradable plastic chambers and harvest autologous tissue flaps, which prolongs the operation time and causes potential damage to donor sites. We improved the TEC strategy by combining bioresorbable polycaprolactone (PCL) chambers and decellularized adipose tissues (DAT). A miniaturized porous PCL chamber was fabricated based on scaling differences between human and rabbit chests, and basic fibroblast growth factor (bFGF)-loaded DAT successfully prepared. In rabbit models, a highly vascularized adipose tissue that nearly filled up the PCL chamber (5 mL) was generated de novo from 0.5 mL bFGF-loaded DAT. The newly formed tissue had significantly high expressions of adipogenic genes, compared to the endogenous adipose tissue. The concept described here can be exploited for breast tissue engineering. Statement of significanceDecellularized adipose tissue (DAT), which provides infiltrated cells adipogenic microenvironment, can potentially regenerate adipose tissue in vivo. Nevertheless, the volume of regenerated adipose tissue is insufficient to repair large sized tissue defect. Tissue engineering chamber (TEC) could provide a protective space for in situ regeneration of large volume tissue. Herein, a new strategy by combining biodegradable polycaprolactone chambers and basic fibroblast growth factor-loaded decellularized adipose tissue is proposed. In rabbit model, newly formed adipose tissue regenerated from DAT successfully filled the dome shaped chamber with ten folds higher volume than DAT, which is proportionally similar to women breast. This work highlighted the importance of adipogenic microenvironment and protective space for adipose tissue regeneration.

Human umbilical cord mesenchymal stem cell promotes angiogenesis via integrin \u03b21/ERK1/2/HIF-1\u03b1/VEGF-A signaling pathway for off-the-shelf breast tissue engineering

BackgroundMesenchymal stem cells (MSC)-based tissue engineered breast represent the visible future for breast reconstruction after mastectomy. However, autologous MSCs might not be appropriate for the large graft construction due to cell senescence during excessive cell expansion, thus hindering its further off-the-shelf application. The human umbilical cord mesenchymal stem cells (hUCMSCs) have been found to induce low immune response and can be easily stored, making them ideal for off-the-shelf tissue engineering application. Here, we explored the feasibility of using umbilical cord mesenchymal stem cells as tissue-engineered breast seed cells.MethodsThe allogenic hUCMSCs were injected into transplanted fat tissue with or without breast scaffolds as an alternative for breast tissue engineering in vivo, and its potential mechanism of angiogenesis in vitro was explored.ResultsTransplantation of hUCMSCs promoted proliferation, migration, and angiogenesis of human umbilical vein endothelial cells (HUVECs) through paracrine mechanism by activating the integrin β1/ERK1/2/HIF-1α/VEGF-A signaling pathway. Histological examination of grafted fat revealed that the group which received hUCMSCs transplantation had more fat tissue [(93.60 ± 2.40) %] and fewer MAC2+CD206− M1 macrophages [(0.50 ± 0.47) cells/field] compared to the control group [fat tissue (45.42 ± 5.96) and macrophage cells/field (5.00 ± 2.23)]. Moreover, the hUCMSCs- labeled with a tracing dye differentiated into adipocytes and vascular endothelial cells in the adipose tissue. When applied to the tissue-engineered breast with a scaffold, the group treated with hUCMSCs had more adipose tissues and CD31+ cells than the control group.ConclusionsThese results demonstrate that allogeneic hUCMSCs promote the regeneration of adipose tissue and can be used to construct a tissue engineered breast.

Cellulose Nanofiber-Based Hydrogels Embedding 5-FU Promote Pyroptosis Activation in Breast Cancer Cells and Support Human Adipose-Derived Stem Cell Proliferation, Opening New Perspectives for Breast Tissue Engineering.

The structure and biocompatibility analysis of a hydrogel based on cellulose nanofibers (CNFs) combined with alginate/pectin (A.CNF or P.CNF) and enriched with 1% or 5% 5-FU revealed more favorable properties for the cellular component when pectin was dispersed within CNFs. 5-Fluorouracil (5-FU) is an antimetabolite fluoropyrimidine used as antineoplastic drug for the treatment of multiple solid tumors. 5-FU activity leads to caspase-1 activation, secretion and maturation of interleukins (IL)-1, IL-18 and reactive oxygen species (ROS) generation. Furthermore, the effects of embedding 5-FU in P.CNF were explored in order to suppress breast tumor cell growth and induce inflammasome complex activation together with extra- and intracellular ROS generation. Exposure of tumor cells to P.CNF/5-FU resulted in a strong cytotoxic effect, an increased level of caspase-1 released in the culture media and ROS production—the latter directly proportional to the concentration of anti-tumor agent embedded in the scaffolds. Simultaneously, 5-FU determined the increase of p53 and caspase-1 expressions, both at gene and protein levels. In conclusion, P.CNF/5-FU scaffolds proved to be efficient against breast tumor cells growth due to pyroptosis induction. Furthermore, biocompatibility and the potential to support human adipose-derived stem cell growth were demonstrated, suggesting that these 3D systems could be used in soft tissue reconstruction post-mastectomy.

Additive manufacturing and large deformation responses of highly-porous polycaprolactone scaffolds with helical architectures for breast tissue engineering

ABSTRACT Helical architectures were designed for the additive manufacturing of highly flexible polycaprolactone (PCL) scaffolds for engineering soft tissues, which commonly require high flexibility and predominantly function under large deformation conditions. It was found that the design parameters like revolution and radius of helical architectures highly affected the filament fusion or bonding during the fabrication process. The bonding-induced interlaced helical architectures resulted in a more uniform deformation pattern and a lower modulus. μCT-based finite element method was established to predict the large deformation responses of the scaffolds with helical architectures and patient-specific scaffold potentially for breast reconstruction, which showed well agreement with the experimental results. The fabricated scaffolds exhibited good shape recovery capability even under cyclical compression at a strain of about 20% for 10000 times. This exploration offers a promising way to predict the mechanical responses of flexible scaffolds with complex helical architectures under large deformation conditions.

A Preclinical Animal Model for the Study of Scaffold-Guided Breast Tissue Engineering.

Scaffold-guided breast tissue engineering (SGBTE) has the potential to transform reconstructive breast surgery. Currently, there is a deficiency in clinically relevant animal models suitable for studying novel breast tissue engineering concepts. To date, only a small number of large animal studies have been conducted and characterization of these large animal models is poorly described in the literature. Addressing this gap in the literature, this publication comprehensively describes our original porcine model based on the current published literature and the experience gained from previous animal studies conducted by our research group. In a long-term experiment using our model, we investigated our SGBTE approach by implanting 60 additively manufactured bioresorbable scaffolds under the panniculus carnosus muscle along the flanks of 12 pigs over 12 months. Our model has the flexibility to compare multiple treatment modalities where we successfully investigated scaffolds filled with various treatments of immediate and delayed fat graft and augmentation with platelet rich plasma. No wound complications were observed using our animal model. We were able to grow clinically relevant volumes of soft tissue, which validates our model. Our preclinical large animal model is ideally suited to assess different scaffold or hydrogel-driven soft tissue regeneration strategies. Impact statement The ability to regenerate soft tissue through scaffold-guided tissue engineering concepts can transform breast reconstructive surgery. We describe an original preclinical large animal model to study controlled and reproducible scaffold-guided breast tissue engineering (SGBTE) concepts. This model features the flexibility to investigate multiple treatment conditions per animal, making it an efficient model. We have validated our model with a long-term experiment over 12 months, which exceeds other shorter published studies. Our SGBTE concept provides a more clinically relevant approach in terms of breast reconstruction. Future studies using this model will support the translation of SGBTE into clinical practice.

Adipose tissue-derived mesenchymal stem cells for breast tissue regeneration.

With an escalating incidence of breast cancer cases all over the world and the deleterious psychological impact that mastectomy has on patients along with several limitations of the currently applied modalities, it's plausible to seek unconventional approaches to encounter such a burgeoning issue. Breast tissue engineering may allow that chance via providing more personalized solutions which are able to regenerate, mimicking natural tissues also facing the witnessed limitations. This review is dedicated to explore the utilization of adipose tissue-derived mesenchymal stem cells for breast tissue regeneration among postmastectomy cases focusing on biomaterials and cellular aspects in terms of harvesting, isolation, differentiation and new tissue formation as well as scaffolds types, properties, material-host interaction and an in vitro breast tissue modeling.

Tuning the mechanics of 3D-printed scaffolds by crystal lattice-like structural design for breast tissue engineering

Breast tissue engineering is a promising alternative to standard treatments for breast defects. Although there is a consensus that the mechanical property of the scaffold should best match the reconstructed tissue, the simulation of the soft and elastic tactility of native breast tissues using conventional materials and architecture design requires further study. Previous research has shown that the crystal microstructure-like design can drastically alter the mechanical properties of the constructed scaffolds. In this study, we designed and additive manufactured four kinds of breast scaffolds using polyurethane and termed their architectures as N5S4, N9S8, N7S6 and N4S6. The basic unit cell of each scaffold was similar to a lattice structure from the isometric crystal system. The scaffolds possessed identical porosity but different mechanical properties in which the compressive modulus of the softest scaffolds (N5S4) were similar to that of native breast tissue. When applied in the construction of tissue-engineered breast combining with delayed fat injection technique in nude rat models, the soft scaffolds(N5S4) performed better compared to its stiff counterpart (N4S6), as higher adipose survival, vascularization and milder fibrosis could be observed in N5S4 scaffolds . Lastly, using finite element analysis, we further investigated the influence of the unit cell architectures on the mechanical properties of the scaffolds and simulated the deformation as well as stress distribution patterns of the implanted scaffolds in detail. Thus, a crystal lattice-like architecture design was introduced to tune the mechanical properties of the scaffolds and match the requirements for tissue engineering applications.

A Tissue Expander–like Scaffold With Photothermal Tumor Ablation Property for Breast Tissue Engineering

BACKGROUND: Tissue engineering–based breast reconstruction after mastectomy is a promising alternative to traditional treatments.1,2 Nevertheless, it could so far neither prevent the potential breast cancer recurrence nor solve the problem of covered skin shortage. PURPOSE: Here we reported the construction of a novel breast tissue engineering scaffold. Benefiting from the photothermal effect of graphene, it can ablate breast cancer cells and recover its shape in a tissue expander-like manner. MATERIALS AND METHODS: Different concentrations of graphene nanoparticles (GNs) were used to functionalize the dome-shaped 3-dimensional–printed polyurethane scaffolds (GfS). Subsequently, GfS were remodeled into disk-like temporary shape. Afterward, GfS were exposed to 808 nm laser with different light intensity, the temperature change was captured by infrared imaging device, and the shape recovery rate was measured by vernier caliper. At last, tumor ablation study was performed using MDA-MB-231 cell line in vitro under 808 nm laser photothermal treatment. RESULTS: The scaffolds functionalized with higher concentration of GN displayed higher degree of blackness and higher temperature rising after laser exposure. In addition, light intensity was also positively correlated with the temperature rising. Laser illuminating could trigger the shape recovery of GfS from temporarily disk-like shape toward their original dome shape. The shape recovery ability of GfS is positively correlated with the light intensity. After exposing to 808 nm laser, GfS could ablate the surrounded MDA-MB-231 breast cancer cells in a GN concentration and light intensity–dependent manner. CONCLUSION: After being irradiated by 808 nm laser, the 3-dimensional–printed polyurethane scaffold functionalized with GNs can recover its initial shape in a tissue expander-like manner and ablate the breast cancer cells. This multifunctional scaffold could potentially be used for tissue engineering–based breast reconstruction to address the problem of covered skin shortage and tumor recurrence after mastectomy. REFERENCES: 1. Findlay MW, Dolderer JH, Trost N, et al. Tissue-engineered breast reconstruction. Plast Reconstr Surg. 2011;128:1206–1215. 2. Chhaya MP, Melchels FP, Holzapfel BM, et al. Sustained regeneration of high-volume adipose tissue for breast reconstruction using computer aided design and biomanufacturing. Biomaterials. 2015;52:551–560.

Breast Augmentation and Reconstruction from a Regenerative Medicine Point of View: State of the Art and Future Perspectives.

Breast reconstruction and augmentation are very common procedures, yet the prevailing current methods utilize silicone implants that may have significant local complications requiring reoperation. Lipofillling is increasingly used to contour and is considered safe, however, its utility is limited by significant volume loss. A new approach could offer an alternative and increase the scope of patient choice. A small number of teams around the world are investigating a breast tissue engineering (TE) paradigm. Conventional breast TE concepts are based on seeding a scaffold with the patients' own stem cells. However, the clinical viability of many of these approaches is limited by their costs in relevant volumes. In this article the state of the art of tissue-engineered breast reconstruction is reviewed and future perspectives are presented and discussed.

Evaluation of polycaprolactone − poly-D,L-lactide copolymer as biomaterial for breast tissue engineering

The potential of the copolymer polycaprolactone-co-poly-d,l-lactic acid (PCLLA) as a biomaterial for scaffold-based therapy for breast tissue engineering applications was assessed. First, the synthesized PCLLA was evaluated for its processability by means of additive manufacturing (AM). We found that the synthesized PCLLA could be fabricated into scaffolds with an overall gross morphology and porosity similar to that of polycaprolactone. The PCLLA scaffolds possessed a compressive Young's modulus (ca 46 kPa) similar to that of native breast (0.5 − 25 kPa), but lacked thermal stability and underwent thermal degradation during the fabrication process. The PCLLA scaffolds underwent rapid degradation in vitro which was characterized by loss of the scaffolds' mechanical integrity and a drastic decrease in mass-average molar mass (Mw) and number-average molar mass (Mn) after 4 weeks of immersion in phosphate buffer solution maintained at 37 °C. The tin-catalysed PCLLA scaffold was also found to have cytotoxic effects on cells. Although the initial mechanical properties of the PCLLA scaffolds generally showed potential for applications in breast tissue regeneration, the thermal stability of the copolymer for AM processes, biocompatibility towards cells and degradation rate is not satisfactory at this stage. Therefore, we conclude that research efforts should be geared towards fine-tuning the copolymer synthesizing methods. © 2016 Society of Chemical Industry

Quo Vadis Breast Tissue Engineering?

Quo Vadis Breast Tissue Engineering?

Breast Tissue Engineering

Breast Tissue Engineering

Breast Tissue Engineering

INTRODUCTION: Decellularization of tissues provides inductive extra-cellular matrices (ECM) for effective organ reconstruction: this promising approach has not been translated to breast reconstruction yet.1,2 We investigated the effectiveness of different decellularization protocols applied to porcine mammary glands with the purpose of developing an inductive biological matrix for prospective breast tissue engineering. METHODS: We cut porcine mammary glands into homogeneous samples (10x10x2cm) and processed these according to three different decellularization protocols (A, B, C). All protocols combined multiple chemical treatments (A: 0.02% trypsin, 0.05% ethylenediaminetetraacetic acid-EDTA, 3% Triton X-100, 4% deoxycholic acid; B: collagenase 3mg/g, 0.02% trypsin, 0.05% EDTA, 10U/mL, 10U/mL lipase; C: collagenase 3mg/g, 0.05% EDTA, 4% sodium deoxycholate, 1% sodium dodecyl sulfate, 0.9% NaCl in TRIS-HCl containing protease inhibitors). We analyzed processed specimens by macroscopic (morphologic) and microscopic methods (Hematoxylin and Eosin staining, Immuno-fluorescent labeling with 4′,6-diamidino-2-phenylindole-DAPI, quantitative measurement of DNA and DNA fragment size) to assess quality of decellularization and structural preservation of the matrix. RESULTS: Harvested mammary glands could be molded to required shape; adjacent glands could be harvested together (up to 700grams). Maximal size of obtainable glands based on a single blood supply varied (average: 20x40x3cm). Blood supply was based on a single reliable vascular pedicle, potentially suitable for microsurgical anastomosis in vivo. Decellularization protocols had variable effectiveness: all samples showed macroscopic evidence of decellularization preserving original morphology at gross examination. DAPI, quantitative measurement of DNA (below 50 ng/mg dry tissue weight) and of DNA fragment size (below 200 base-pairs) showed effective reduction of immunogenic components in each protocol. At histological analysis (Hematoxylin and Eosin) protocol A provided a morphology more closely resembling native architecture of ECM and a more effective preservation of the vascular and ductal networks. Protocols B and C, instead, slightly damaged and altered histological structure of the matrix. CONCLUSIONS: Decellularization of porcine mammary tissue represents a novel and reliable preliminary approach to develop a bio-inductive matrix for potential subsequent breast tissue engineering.

Breast tissue engineering: decellularized scaffolds derived from porcine mammary glands

Breast tissue engineering: decellularized scaffolds derived from porcine mammary glands

The potential in breast tissue engineering for the combined effects of linoleic acid and tamoxifen

Literature to date has strongly suggested that linoleic acid (LA) enhances mammary cancer cell proliferation when used in the range of 0·5–20 μg/ml. In contrast, the current in vitro studies show that deoxyribonucleic acid (DNA) levels of estrogen receptor-positive (ER+) MCF7 breast cancer cells were diminished following treatment with 30 μg/ml (100 μM) LA. MCF7 cells, when treated for 6 days with LA, consumed significantly less glucose than untreated controls (P-value<0·01). MFC7 cells treated with 30 μg/ml LA and 10 μM tamoxifen had even lower levels of DNA and lower glucose uptake. The same combination treatment of tamoxifen and LA was applied to a noncancerous mammary cell line, MCF10A, and did not have a significant effect on MCF10A DNA concentrations. Linoleic acid and its byproducts are important to cell proliferation and tissue reconstruction and, in combination with tamoxifen, can provide a uniquely different approach to soft tissue engineering. That is, LA and tamoxifen-loaded scaffolds may provide a viable reconstructive approach for patients undergoing lumpectomy and mastectomy by encouraging natural breast healing while limiting the ability of ER+ cancer cells to regrow. This approach could allow the suppression of estrogen-dependent mammary carcinomas while allowing natural cell proliferation after a mastectomy or lumpectomy.

CAD/CAM-assisted breast reconstruction

The application of computer-aided design and manufacturing (CAD/CAM) techniques in the clinic is growing slowly but steadily. The ability to build patient-specific models based on medical imaging data offers major potential. In this work we report on the feasibility of employing laser scanning with CAD/CAM techniques to aid in breast reconstruction. A patient was imaged with laser scanning, an economical and facile method for creating an accurate digital representation of the breasts and surrounding tissues. The obtained model was used to fabricate a customized mould that was employed as an intra-operative aid for the surgeon performing autologous tissue reconstruction of the breast removed due to cancer. Furthermore, a solid breast model was derived from the imaged data and digitally processed for the fabrication of customized scaffolds for breast tissue engineering. To this end, a novel generic algorithm for creating porosity within a solid model was developed, using a finite element model as intermediate.

Eighth IQUAM Consensus Conference Position Statement: Transatlantic Innovations, April 2009

On April 7, 2009, the International Committee for Quality Assurance, Medical Technologies and Devices in Plastic Surgery (IQUAM) issued its 8th Position Statement. IQUAM is a professional medical and scientific organization committed to the surveillance of existing and new technologies and devices in plastic surgery. IQUAM periodically reviews and evaluates updated international literature and studies and scientific data, and recommends standards of treatment for plastic surgery devices and technologies. IQUAM proscribes potentially deleterious use of products, devices, and technologies, or their unintended application or application for unsuitable indications. Presentations of an international panel of experts made during the Transatlantic Innovations Symposia in Paris, in April of 2009, were reviewed by an advisory board that prepared the position statement for distribution to plastic surgeons and regulatory bodies. The advisory panel was international in nature and included plastic surgeons with expertise in the specific areas evaluated. Three clinical areas of greatest concern to plastic surgeons were evaluated for efficacy and safety: silicone breast implants, tissue engineering, and injectable therapies. Specific recommendations designed to increase clinical safety and patient education for informed consent were made in each area.