The aging process reduces the number of fibroblasts in the dermis and their ability to synthesize collagen and elastin15. Multiple dermal fillers for soft tissue augmentation are available on the market. One type, HA fillers, has become particularly popular in recent years16. An ideal filler should have permanence, good biocompatibility, chemical inertness, soft and easy-to-use consistency, and minimal adverse reactions17. However, even in the hands of the most experienced physicians, unwanted side effects can occur with dermal fillers. Because autologous fibroblasts offer long-term efficacy and an absence of allergic reactions, they are a natural alternative to filler materials18.
In the present study, the HA group demonstrated a significant volume improvement immediately after the HA injection and at the 1-month follow-up compared with baseline (P = 0.000 and 0.000, respectively). By contrast, the autologous fibroblast group had significant volume improvements at all follow-ups compared with baseline (P = 0.000, 0.004, 0.000, 0.000 and 0.003). These findings prove that using autologous fibroblast injections can produce sustained clinical improvements in skin that has suffered collagen degradation19. A previous study biometrically assessed the skin changes caused by autologous fibroblast injections. The research revealed significant increases in epidermal and dermal thicknesses after 6 months relative to the pretreatment values20.
In our study, most patients in the HA group had clinical improvements at the 1-month follow-up (50%) compared with baseline. However, no changes were detected at the 3-, 6-, and 12-month follow-ups. The autologous fibroblast group showed improvements only at the 3- and 6-month follow-ups.
Earlier investigations found that HA fillers in NLFs can show clinical results 1 month after injection, with satisfaction maintained at 6 months21. In our study, the HA fillers degraded over time, but the autologous fibroblast injections resulted in gradual improvements, as evidenced by our patient self-assessments. Fibroblast injections have previously been shown to require a more extended period before their effects are observed (at least 1–2 months following the completion of treatment) but without any risk of hypersensitivity reactions13. The findings of the current investigation are consistent with those of another study that used autologous fibroblasts in NLFs. That research observed sustained soft tissue augmentation at 3 months with continued clinical improvement at 6 months19. The more extended period before wrinkle improvement becomes apparent with autologous fibroblast injections than with HA fillers results from collagen deposition not using direct volume replacement. Consequently, fibroblast injections have a more gradual effect than HA fillers, which show immediate results14.
More autologous fibroblast patients than HA patients reported improvements in their NLFs at the 3-, 6-, and 12-month follow-ups. This finding is similar to the results of another study. It found that 81.6% of the patients treated with autologous fibroblasts demonstrated continued therapeutic benefits even at the 12-month follow-up13.
Other novel autologous fibroblast combinations have been formulated to produce a faster onset of results with more prolonged clinical efficacy. For instance, Jiang et al. combined autologous fibroblasts and keratin as a soft tissue filler. The researchers found that 90% of their patients had significant NLF improvements at the 1-month follow-up. In addition, the improvements were maintained in 93.8% of cases at the 24-month follow-up22. In other research, autologous fibroblasts combined with plasma gel (Fibrogel) showed persistent improvements in the infraorbital area and lower face at the 3-, 6-, and 12-month follow-ups, with minimal adverse reactions23.
Regarding adverse reactions in the present work, we had 1 patient in the autologous fibroblast group who experienced mild transient erythema. The condition resolved spontaneously within a day. Erythema is a commonly reported adverse reaction among patients injected with autologous fibroblasts14,20.
Currently, fibroblast injections are indicated for the treatment of NLFs. Autologous fibroblast treatment of NLFs is a promising option for patients. As autologous fibroblasts are not volume fillers, they are ideal for treating fine lines. On the other hand, possible disadvantages of autologous fibroblasts over HA fillers are their additional costs (which can be as high as 4 times when comparing to 1 cc of HA fillers) and the long lead time needed to harvest and culture the fibroblasts.
Our study was limited by its small sample size, and the follow-up duration might not be long enough to determine the maximum efficacy of the treatment. We recommend that further studies be conducted with larger sample sizes and longer follow-ups to establish the longevity of autologous fibroblast injection therapy.