Tracking and Increasing Viability of Topically Injected Fibroblasts Suspended in Hyaluronic Acid Filler

Abstract

A new injectable tissue-engineered soft tissue consisting of a mixture of hyaluronic acid (HA) filler and cultured human fibroblasts have been developed by the authors. To establish this method as a standard treatment, a further study was required to determine whether the injected fibroblasts could stay at the injected place or move to other sites. In addition, effective strategies were needed to increase viability of the injected fibroblasts. The purpose of this study was to track the injected fibroblasts and to determine the effect of adding prostaglandin E1 (PGE1) or vitamin C on the viability of fibroblasts.Human fibroblasts labeled with fluorescence dye were suspended in HA filler and injected into 4 sites on the back of nude mice. The injected bioimplants consisted of one of the 4 followings: HA filler without cells (HA group), fibroblasts suspended in HA filler (HA þ FB group), PGE1-supplemented fibroblasts in HA filler (HA þ FB þ PGE1 group), and vitamin C-supplemented fibroblasts in HA filler (HA þ FB þ VC group). At 4 weeks after injection, locations and intensities of the fluorescence signals were evaluated using a live imaging system.The fluorescence signals of the fibroblast-containing groups were visible only at the injected sites without dispersing to other sites. The HA þFB þ PGE1 group showed a significantly higher fluorescence signal than the HA þ FB and the HA þ FB þVC groups (P < 0.05, each). There was no statistical difference between the HA þ FB and HA þ FB þVC groups (P ¼ 0.69).The results of the current study collectively suggest that injected fibroblasts suspended in HA filler stay at the injected place without moving to other sites. In addition, PGE1 treatment may increase the remaining rhodamine B isothiocynanate dye at the injected site of the human dermal fibroblasts.F or correction of facial wrinkles or soft-tissue augmentation, a number of commercially prepared injectable fillers have been developed. 1-4 Currently, soft-tissue filler products based on hyaluronic acid (HA) are widely used, because they have a low potential for allergic reactions, require no skin testing, can be stored at room temperature, and have no risk of bovine spongiform encephalopathy unlike collagen. Although HA fillers have shown to be relatively safe and convenient to administrate, their variable degrees of resorption require repeated injections. To overcome these drawbacks, the authors created a new injectable filler consisting of a mixture of HA filler and living cultured human fibroblasts. 5,6 The results of our previous experimental and clinical studies showed that cultured human dermal fibroblasts mixed into HA filler can produce human dermal matrices with extended in vivo stability and may have a potential to be used as a long-lasting injectable soft-tissue filler. To establish this method as a standard treatment, a further study, however, is required to determine whether the fibroblasts could stay at the injected place or move to other sites through examination of the location, distribution, and long-...

Assessment of Long-term Outcomes of Soft-Tissue Augmentation by Injecting Fibroblasts Suspended in Hyaluronic Acid Filler

“…The results demonstrated that fluorescence signals of the fibroblasts were visible only at the injection sites without dispersing to other sites. 9 In addition, 4 weeks after injection, 28.1% of the fluorescence signals were still present at the injection site. However, directcell labeling was used in that study, resulting in decreased numbers of labels per individual cell, since the label could have been diluted when cells were divided.…”

“…7 In 2003, our research group conducted an animal study to evaluate the feasibility of using a commercial HA filler combined with cultured human dermal fibroblasts to enhance the longevity of injected bioimplants. 8,9 Those results demonstrated that HA filler mixed with cultured human dermal fibroblasts could produce human dermal matrices successfully with extended in vivo stability. Therefore, it might have potential as a living graft for long-lasting soft-tissue filler.…”

“…However, commercial HA fillers were originally developed as filling materials of skin and soft tissue, not as cell carriers or suitable scaffolds . In 2003, our research group conducted an animal study to evaluate the feasibility of using a commercial HA filler combined with cultured human dermal fibroblasts to enhance the longevity of injected bioimplants . Those results demonstrated that HA filler mixed with cultured human dermal fibroblasts could produce human dermal matrices successfully with extended in vivo stability.…”

“…Therefore, it might have potential as a living graft for long-lasting soft-tissue filler. 8,9 Based on the results of our experimental study, a clinical pilot study was undertaken in 2003 to evaluate the clinical outcome of this method, particularly for augmentation rhinoplasty cases. 10 This method was well tolerated, all the patients were satisfied with the achieved long-term result, and no complications occurred.…”

Effect of bFGF and fibroblasts combined with hyaluronic acid-based hydrogels on soft tissue augmentation: an experimental study in rats

“…Recently, HA-based hydrogels containing cultured fibroblasts and fibroblast-conditioned media have been applied experimentally [22–24] and clinically [25, 26], and they have shown improved efficiency [27]. It is known that basic fibroblast growth factors (bFGF) can induce the migration of mesenchymal stem cells and human fibroblasts [28, 29].…”