Injectable Skin-Derived Paste Shows Promise for Breast Reconstruction After Cancer Surgery
Key Insights
Korean researchers at Seoul National University Bundang Hospital developed SC Fill paste (search), an injectable tissue filler made from processed human skin that could offer a less invasive alternative to traditional breast reconstruction methods.
The paste demonstrated superior blood vessel formation and cell recruitment compared to commercial products in six-month rat studies, with inflammatory markers declining over time.
The injectable format allows surgeons to adapt the material to irregular defect shapes without additional incisions, potentially reducing scarring and recovery times for breast cancer (search) patients.
Women facing breast-conserving surgery after cancer diagnosis often confront a challenging balance between removing sufficient tissue for safety and preserving breast appearance. Korean researchers have developed a potential solution that could transform reconstructive options for these patients.
A team from Seoul National University Bundang Hospital created SC Fill paste (search), an injectable tissue filler made from processed human skin that aims to fill gaps left after tumor removal without requiring complex reconstructive procedures. The research, published in ACS Applied Bio Materials, represents a significant departure from current approaches that rely on prosthetic implants or tissue transplanted from other body parts.
Novel Injectable Approach Addresses Current Limitations
Traditional reconstructive procedures often fall short when patients have smaller breasts or larger tumors, leaving insufficient tissue for conventional rearrangement techniques. Borrowing tissue from other body parts presents additional complications, including extra scarring and prolonged recovery times.
SC Fill paste (search) differs fundamentally from current sheet-form materials used in breast reconstruction. While existing sheets require shaping and suturing into place—challenging when defects have irregular shapes or extend into deeper tissue—the injectable format allows surgeons to adapt the material to each patient's specific defect geometry.
Dr. Chan-Yeong Heo and colleagues processed donated human skin through steps that remove all cellular material while retaining key extracellular-matrix components and measurable levels of growth factors that help tissues rebuild. They ground the material into microscopic particles averaging about 190 micrometers in size and mixed it into a paste deliverable through a syringe.
Reduced Immunogenicity and Enhanced Biocompatibility
The processed material showed dramatically reduced levels of components that typically trigger immune responses. Double-stranded DNA content dropped to 18 nanograms per milligram, well below the 50 ng/mg commonly accepted threshold for implanted materials. Laboratory analysis confirmed complete elimination of MHC-I proteins (search), one of the primary triggers for tissue rejection.
Simultaneously, the paste retained more than twice the collagen content of PC-1, a commercial micronized acellular dermal matrix control product, and showed moderate retention of growth factors known to promote healing and blood vessel formation, though overall levels remained lower than native tissue.
Six-Month Animal Studies Demonstrate Integration
Testing in 80 rats provided evidence about the material's behavior after implantation. Researchers implanted small amounts of SC Fill paste (search) under the skin and tracked results over six months, comparing against two commercial tissue products. The testing was performed in subcutaneous tissue on the rats' backs, not in breast defect reconstruction.
SC Fill paste (search) promoted robust blood vessel formation and attracted more fibroblasts—cells responsible for creating new tissue. Blood vessel counts within the implanted material increased progressively, with SC Fill paste showing significantly higher vessel numbers at three and six months compared to PC-1. The material also attracted significantly more fibroblasts than commercial products at the one-month mark.
Inflammatory markers revealed favorable responses. Levels of proteins like TNF-α (search), IL-1β (search), IL-6, and IL-8 (search) peaked at the one-month mark but declined steadily over following months. By six months, SC Fill paste (search) samples showed significantly lower IL-1β levels compared to the one-month time point, indicating the inflammatory response had largely resolved.
Evidence of Appropriate Tissue Remodeling
The material appeared to undergo appropriate remodeling, with expression of enzymes that break down and rebuild tissue scaffolds following expected patterns. These enzymes were active early but declined over time as new collagen accumulated. Type I collagen (search) increased gradually throughout the six-month period, while type III collagen (search) peaked early then decreased—a pattern consistent with typical wound-healing phases.
Researchers interpret this as evidence that the body treats the implanted material as a framework for new tissue rather than foreign material requiring isolation.
Clinical Implications and Future Development
For patients, these biological details could translate into better outcomes if the material performs similarly in humans. A filler that promotes blood vessel growth and attracts appropriate cells while showing declining inflammation should integrate more naturally than materials provoking persistent immune responses.
The study has notable limitations. All animal testing was conducted in rats, whose immune systems and tissue healing processes differ from humans in important ways. The six-month observation period captured acute and intermediate phases of tissue integration but may have missed longer-term issues. The authors note future optimization needs, including improving mechanical properties such as elastin content and how well the paste maintains form after placement.
The research showed mixed results, with the experimental material outperforming commercial controls in some measures like vascularization and cell recruitment while showing thicker capsule formation compared to one control product at the six-month mark. Significant additional research, including larger animal studies and eventual human clinical trials, would be required before this material could be used in patients.