Simple and robust 3D bioprinting of full-thickness human skin tissue

Artificial skins have been used as skin substitutes for wound healing in the clinic, and as in vitro models for safety assessment in cosmetic and pharmaceutical industries. The three-dimensional (3D) bioprinting technique provides a promising strategy in the fabrication of artificial skins. Despite the technological advances, many challenges remain to be conquered, such as the complicated preparation conditions for bio-printed skin and the unavailability of stability and robustness of skin bioprinting. Here, we formulated a novel bio-ink composed of gelatin, sodium alginate and fibrinogen. By optimizing the ratio of components in the bio-ink, the design of the 3D model and the printing conditions, a fibroblasts-containing dermal layer construct was firstly fabricated, on the top of which laminin and keratinocytes were sequentially placed. Through air-liquid interface (ALI) culture by virtue of sterile wire mesh, a full-thickness skin tissue was thus prepared. HE and immunofluorescence staining showed that the bio-printed skin was not only morphologically representative of the human skin, but also expressed the specific markers related to epidermal differentiation and stratum corneum formation. The presented easy and robust preparation of full-thickness skin constructs provides a powerful tool for the establishment of artificial skins, holding critical academic significance and application value.

Autologous full-thickness skin graft as reinforcement in parastomal hernia repair: a feasibility study

Background

Parastomal hernia is a common complication of stoma formation and the methods of repair available today are unsatisfactory with high recurrence and complication rates. To improve outcome after surgical repair of parastomal hernia, a surgical method using autologous full-thickness skin grafts as intraperitoneal reinforcement has been developed. The purpose of this study was to evaluate the feasibility of this novel surgical technique in the repair of parastomal hernia.

Methods

A pilot study was conducted between January 2018 and June 2019 on four patients with symptomatic parastomal hernia. They had a laparotomy with suture reduction of the hernia and reinforcement of the abdominal wall with autologous full-thickness skin. They were then monitored for at least 1 year postoperatively for technique-related complications and recurrence.

Results

No major technique-related complications were noted during the follow-up Two patients developed a recurrent parastomal hernia at the long term follow-up. The other two had no recurrence.

Conclusions

Autologous full-thickness skin graft as reinforcement in parastomal hernia repair is feasible and should be evaluated in a larger clinical trial.

One-year outcome after repair of giant incisional hernia using synthetic mesh or full-thickness skin graft: a randomised controlled trial

Purpose

Repair of giant incisional hernia often requires complex surgery and the results of conventional methods using synthetic mesh as reinforcement are unsatisfactory, with high recurrence and complication rates. Our hypothesis was that full-thickness skin graft (FTSG) provides an alternative reinforcement material for giant incisional hernia repair and that outcome is improved. The aim of this study was to compare FTSG with conventional materials currently used as reinforcement in the repair of giant incisional hernia.

Methods

A prospective randomised controlled trial was conducted, comparing FTSG with synthetic mesh as reinforcement in the repair of giant (> 10 cm minimum width) incisional hernia. One-year follow-up included a blinded clinical examination by a surgeon and objective measurements of abdominal muscle strength using the Biodex-4 system.

Results

52 patients were enrolled in the study: 24 received FTSG and 28 synthetic mesh. Four recurrences (7.7%) were found at 1-year follow-up, two in each group. There were no significant differences regarding pain, patient satisfaction or aesthetic outcome between the groups. Strength in the abdominal wall was not generally improved in the study population and there was no significant difference between the groups.

Conclusion

The outcome of repair of giant incisional hernia using FTSG as reinforcement is comparable with repair using synthetic mesh. This suggests that FTSG may have a future place in giant incisional hernia repair.

synthetic mesh in the repair of giant incisional hernia: a randomized controlled multicenter study

PURPOSE

Repair of large incisional hernias includes the implantation of a synthetic mesh, but this may lead to pain, stiffness, infection and enterocutaneous fistulae. Autologous full-thickness skin graft as on-lay reinforcement has been tested in eight high-risk patients in a proof-of-concept study, with satisfactory results. In this multicenter randomized study, the use of skin graft was compared to synthetic mesh in giant ventral hernia repair.

METHODS

Non-smoking patients with a ventral hernia > 10 cm wide were randomized to repair using an on-lay autologous full-thickness skin graft or a synthetic mesh. The primary endpoint was surgical site complications during the first 3 months. A secondary endpoint was patient comfort. Fifty-three patients were included. Clinical evaluation was performed at a 3-month follow-up appointment.

RESULTS

There were fewer patients in the skin graft group reporting discomfort: 3 (13%) vs. 12 (43%) (p = 0.016). Skin graft patients had less pain and a better general improvement. No difference was seen regarding seroma; 13 (54%) vs. 13 (46%), or subcutaneous wound infection; 5 (20%) vs. 7 (25%). One recurrence appeared in each group. Three patients in the skin graft group and two in the synthetic mesh group were admitted to the intensive care unit.

CONCLUSION

No difference was seen for the primary endpoint short-term surgical complication. Full-thickness skin graft appears to be a reliable material for ventral hernia repair producing no more complications than when using synthetic mesh. Patients repaired with a skin graft have less subjective abdominal wall symptoms.