Treatment of burns and chronic wounds using a new cell transfer dressing for delivery of autologous keratinocytes

This study describes a new methodology for delivering cultured autologous keratinocytes to wounds on a sterile medical grade polymer coated with a chemically defined plasma polymerised functional surface containing 20% carboxylic acid (referred to as PPS). Seven patients (two acute major burns and five chronic non-healing wounds) were treated with applications of autologous keratinocytes delivered on a 6 cm diameter medical grade polymer disc whose surface was functionalised by PPS. For initial keratinocyte expansion a split-thickness skin biopsy was taken from each patient followed by keratinocyte isolation and expansion and, where required for repeated applications, freezing down of keratinocytes. After expansion, cells were cultured on the PPS for 2 days then the PPS with cells was inverted onto the patients wound bed to allow cell transfer to wound beds. For two burns patients transfer of cells from PPS onto donor sites was seen for both patients and it appeared to facilitate healing of grafted burns wounds. For five patients with intractable chronic wounds (with nine ulcers in total) repeated applications of cells resulted in complete healing in 5/9 ulcers with a major reduction in ulcer size for all other (4/9) ulcers. This reduction in ulcer size improved the wound conditions for two of these patients such that they were then considered suitable for conventional grafting and orthopaedic surgery respectively. In conclusion, PPS delivery of autologous cells is a promising approach for acute burns injuries and chronic wounds.This paper is dedicated to the memory of Mr Archibald Newman (Patient 3) who sadly died in January 2005.     

A novel cell-adhesive scaffold material for delivering keratinocytes reduces granulation tissue in dermal wounds

Novel peptide-conjugated chitosan membranes were fabricated and used to deliver keratinocytes to dermal wounds in mice. Three active peptides of 12 or 13 amino acids each, RLVSYNGIIFFLK (A5G27), ASKAIQVFLLAG (A5G33), and AGTFALRGDNPQG (A99) were selected from a cell-adhesive peptide library of laminin, a major constituent of basement membrane. The peptides were synthesized and coupled to chitosan membranes, and the resulting peptide–chitosan membranes were tested for keratinocyte attachment. Two of the peptides that bind to cell surface heparin-like receptors (A5G27 and A5G33) were found to promote strong keratinocyte attachment, whereas the one that binds to integrin (A99) was inactive. Subsequently, A5G27– and A5G33–chitosan membranes were tested as vehicles for keratinocyte delivery in a wound model. We found that keratinocytes were delivered into the full-thickness wound with either membrane. Using the A5G33–chitosan membrane, we further evaluated the activity of the delivered keratinocytes in wound healing. Immunohistochemistry for granulation tissue markers, including tenascin and α-smooth muscle actin, showed that keratinocyte delivery by the present peptide–chitosan membranes in the wound bed provided a favorable condition for keratinocyte migration along the wound surface and reduced granulation tissue formation.     

Autologous keratinocyte suspensions accelerate epidermal wound healing in pigs

BACKGROUND: Tissue culture techniques enable in vitro expansion of keratinocytes that can be used to treat burns and chronic wounds. These keratinocytes are commonly grafted onto the wounds as differentiated sheets of mature epithelium. Less is however known about the effects of transplanting the cells as suspensions. This study evaluated epidermal regeneration in fluid-treated skin wounds treated with suspensions of cultured and noncultured autologous keratinocytes. MATERIALS AND METHODS: Eighty-seven full-thickness excisional skin wounds were created on the back of 6 pigs and then transplanted with either cultured or noncultured autologous keratinocytes. The wounds were enclosed with liquid-tight chambers containing saline to provide a hydrated and standardized environment. RESULTS: Keratinocyte transplantation resulted in several cell colonies within the granulation tissue of the wound. These colonies progressively coalesced and contributed to a new epithelium. The origin of the transplanted keratinocytes was confirmed by histochemical staining of wounds transplanted with transfected keratinocytes expressing beta-galactosidase. Transplantation of 0.125 x 10(6), 0.5 x 10(6), and 2.0 x 10(6) cultured keratinocytes, and 0.5 x 10(6) and 5.0 x 10(6) noncultured keratinocytes, increased reepithelialization dose dependently over saline-treated controls. The epithelial barrier function recovered faster in transplanted wounds as demonstrated by less protein leakage over the wound surface on Days 7-10 as compared to control wounds. Wound reepithelialization and the number of keratinocyte colonies observed in granulation tissue were significantly less in wounds transplanted with noncultured keratinocytes compared to wounds seeded with cultured keratinocytes. CONCLUSION: Our study demonstrates successful transplantation of keratinocyte suspensions and their dose-dependent acceleration of wound repair. Selection of proliferative cells during culture and higher colony-forming efficiency may explain the greater effects observed with cultured keratinocytes.     

The co-application of sprayed cultured autologous keratinocytes and autologous fibrin sealant in a porcine wound model.

We have explored the potential for cultured autologous keratinocytes to form an epidermis when delivered as a spray intermixed with autologous fibrin sealant. Twelve full-thickness wounds in Large White pigs (six wounds in each of two pigs) were isolated from the surrounding skin by 4 cm diameter polytetrafluoroethylene chambers, and grafted with Integra artificial skin (Ethicon). Autologous fibrin sealant was produced 10 days later, using an automated processor unit (Vivostat System, ConvaTec, Bristol Myers Squibb), from 120 ml of autologous citrated blood taken 30 min before keratinocyte application. Nine wounds were sprayed, using a Vivostat System automated applicator unit, with a mixture of the sealant preparation and freshly trypsinised cultured autologous keratinocytes in growth medium, at a density of 1-3 x 10(5) cm(-2). Three control wounds were sprayed with the same mixture without cells. The sealant-cell mixture polymerised and adhered to the wound surface immediately. Histological analysis of biopsies taken following sealant-cell application showed that isolated spherical keratinocytes were distributed throughout the sealant at between 3.1 x 10(4) cm(-2) and 7.6 x 10(4) cm(-2). After 4 days discreet colonies of keratinocytes were observed on the wound bed. At 14 days a multi-layered undulating epidermis was formed, punctuated by sporadic epidermal cysts; the mean area of epithelium was 50.1% (s.d. = 19.7%, n = 9). There was no epithelium in the controls (s.d. = 0, n = 3). The difference was statistically significant (P=0.016). This study suggests that co-sprayed cultured keratinocytes and autologous fibrin sealant may be an effective means of delivering epithelial cells to assist wound healing.     

Naturally occurring growth factors in porcine wounds treated with autologous keratinocytes in a liquid environment

A step toward an improved understanding of the complex mechanisms of growth factor interactions may lie in the detection of endogenous growth factors during normal wound healing. The findings of this study on standardized full thickness wounds in swine, provide direct evidence that growth factors were present in the wound fluid in the picogram range (highest concentrations ranging from 1273 pg/ml for transforming growth factor-beta (TGFβ) to 85.6 pg/ml for platelet-derived growth factor-AB (PDGF-AB ) during healing. The presence of transplanted autologous keratinocyte suspensions and cultured epithelial sheet graft had no significant effect upon the observed growth factor levels, although transplanted keratinocyte cell suspensions (KCS) and cultured epidermal autografts (CEA) did accelerate healing in comparison to control wounds in our model (KCS treated wounds healed in 13.2±0.9 days, CEA in 13.7 days±0.8 and control wounds in 14.7 days±0.3). The variable occurrence of growth factors during normal wound healing may suggest possible mechanisms of growth factor interaction which could have an impact on the future design of their therapeutic use. Received: 28 September 1998 / Accepted: 16 November 1998     

Locomotion of human skin keratinocytes on polystyrene, fibrin, and collagen substrata and its modification by cell-to-cell contacts

Epithelial wound repair assures the recovery of the epithelial barrier after wounding. During wound healing epithelial cells migrate to cover the wound surface. The presented experiments were carried out to compare the migration of human keratinocytes from primary and secondary culture on polystyrene, collagen, and fibrin glue used in clinical techniques. The images of migrating keratinocytes were recorded and analyzed using computer-aided methods. The results show that the character of the substrate strongly affects the speed and turning behavior of keratinocytes locomoting over it. The highest motile activity of human skin keratinocytes was found on fibrin glue substratum. It was found that locomotion of freely moving isolated cells was much faster than that of cell sheets. The autologous keratinocytes cultured in vitro were applied with fibrin glue to cover trophic wounds. The transplantation of human autologous keratinocyte suspension in fibrin glue upon long-lasting trophic wounds appeared to induce rapid and permanent wound healing.     

Healing of full-thickness wounds treated with lyophilized cultured keratinocyte cell lysate in genetically diabetic mice

The effect of a lyophilized cell lysate prepared from cultured human keratinocytes on the healing of full-thickness wounds was evaluated in an impaired healing model. Full-thickness wounds (8 mm in diameter) were made on the dorsal areas of female genetically diabetic mice C57 BL/KsJ (db/db) and their normal (db/+) littermates. Wounds were covered with an occlusive polyurethane film dressing and were treated for 5 days either with the lyophilized cell lysate from cultured human keratinocytes prepared in phosphate-buffered saline solution or with phosphate-buffered saline solution. In normal (db/+) mice, all wounds were closed 16 days after wounding, and more than 90% of the wound closure was due to wound contraction. Wound contraction accounted for a similar extent of wound closure in both lyophilized cell lysate-treated and phosphate-buffered saline solution-treated wounds. In contrast, in the diabetic (db/db) mice, after histologic examination of the wounds 32 days after wounding, four of ten lyophilized cell lysate-treated wounds and four of seven phosphate-buffered saline-treated wounds were found to be closed. Moreover, applications of lyophilized cell lysate from cultured human keratinocytes to full-thickness wounds in diabetic db/db mice significantly decreased the contribution of contraction to wound closure. Day 32 after wounding, contraction contribution to wound closure amounted to 57.7%+/- 4.7% and 80.4%+/- 3.2% (mean +/- standard error of the mean, p < 0.005) of the initial wound areas, respectively, for lyophilized cell lysate-treated and phosphate-buffered saline solution-treated wounds. At this time of wound healing, the thickness of the dermis was increased 1.7-fold by the keratinocyte cell lysate treatment, but neither epithelial migration from the wound edges nor the thickness of the regenerated epithelium were significantly affected. In conclusion, in diabetic (db/db) mice the application of lyophilized cell lysate from cultured human keratinocytes influenced the healing of the dermis and wound contraction, but had no effect on reepithelialization.     

In vitro evaluation of fibrin mat and Tegaderm wound dressing for the delivery of keratinocytes--implications of their use to treat burns

The effectiveness of fibrin mat and Tegaderm delivery systems to maintain clonogenic keratinocytes in culture were evaluated using in vitro methods. A fibrin mat was found to provide a culture environment that is conducive for the proliferation of keratinocytes and supporting their ability to form colonies of good growth potential in vitro. This confirms that the fibrin mat is a good delivery system for cultured epithelial autograft (CEA). In our unit, fibrin-CEA is limited only for the treatment of severe burns due to the high cost of fibrin glue. However, this substrate is able to maintain the regenerative properties of the CEA which is crucial for the treatment of extensive and full thickness burns. Tegaderm, a cost-effective polyurethane wound dressing is able to support keratinocyte cell growth but at a slower rate and with fewer colonies formed compared to the fibrin system. This suggests that Tegaderm can be an alternative approach of delivering autologous cells, limited to treat chronic wounds and less extensive burns. The use of simple and relatively inexpensive bench techniques can potentially serve as a quality control to check for keratinocytes cultured and delivered to every patient in the clinical setting.     

Autologe Keratinozytenkulturen auf Hyaluronsäureestermembranen: Eine Alternative in der komplizierten Wundbehandlung?

Cultivation and transplantation of autologous keratinocytes has been used in the last 15 years to treat complicated wounds of different origin. In spite of excellent technical advancements and clinical experiences cultured keratinocyte grafting still is associated with practical limitations. Application of hyaluronic acid ester membranes as carrier substrate for the transfer of keratinocytes allows improved graft handling, reduces total time required for tissue cultivation and furthermore enhances vitality of the keratinocytes because of possible grafting at semiconfluence.     

Cultured human keratinocytes as a single cell suspension in fibrin glue combined with preserved dermal grafts enhance skin reconstitution in athymic mice full-thickness wounds

Cultured human keratinocytes as a single cell suspension in fibrin glue combined with preserved dermal grafts enhance skin reconstitution in athymic mice full-thickness wounds. The technique of transplanting cultured human keratinocytes suspended as single cells in a fibrin-glue matrix (KFGS) has been recently developed to overcome common disadvantages of standard cultured epidermal sheet grafts. The combination of this method with glycerolized (nonvital) xenograft overlays in standardized nude mice full-thickness wounds, as compared to KFGS alone or controls with no grafts, showed enhancement of epithelial regeneration in terms of epithelial thickness and diminished wound contraction during the 6-week follow-up. Total scar thickness was increased after the combined KFGS/xenograft technique. The time taken to complete wound reepithelialization was similar in the two groups. Reconstitution of the dermo-epidermal junction zone as shown by electron microscopy and immunohistochemistry was enhanced by the KFGS+xenograft technique, showing structures resembling rete ridges 6 weeks postoperatively. The combined KFGS/xenograft technique is able to transfer proliferative single keratinocytes. The method simplifies the application when compared to conventional epithelial sheet grafting and reduces wound contraction when compared to pure keratinocyte grafting. Received: 15 October 1998 / / Accepted: 10 March 1999     

Cultured autologous keratinocytes suspended in fibrin glue (KFGS) with allogenic overgraft for definitive burn wound coverage

In a patient with burns of 88% TBSA autologous cultured keratinocyte fibrin glue suspension (KFGS) overgrafted with fresh split thickness allogenic skin was used as definitive wound coverage after epifascial debridement and temporary allogenic closure. A total of 22% TBSA were closed in this way including a complete leg except the foot. For comparison, the contralateral leg was covered with conventional autologous sheet grafts (CEA). Histology revealed a layered squamous epithelium, and evidence of at least partial integration of allogenic dermis including the formation of a well-organized rete structure even after deep necretomy. Besides the rapid stable closure and good skin quality, the new technique has the advantages of early availability, simple handling, easy repetition, and the transfer of actively proliferating epidermal cells. This is the first case proving that KFGS with allogenic overgrafts leads to permanent epithelialization of large epifascial wounds. The technique compared favorably with CEA with regard to availability, handling, and stability.Presented at the 39th Annual Meeting of the Plastic Surgery Research Council (PSRC), Ann Arbor, June 4–7, 1994     

A comparison of keratinocyte cell sprays with and without fibrin glue

Fibrin glue is an excellent template for cellular migration and has been shown to be an effective delivery system for cultured autologous keratinocytes. We have investigated whether fibrin glue has any benefit on the percentage of epithelial cover when cultured autologous keratinocytes are sprayed onto a freshly debrided wound bed.Three pigs were used for this study. This provided a total of 18 full thickness, vertically orientated wounds, each 4cm in diameter and isolated in PTFE chambers to prevent re-epithelialisation from the wound margins. Eight wounds were sprayed with cultured autologous keratinocytes suspended in 2ml culture medium and eight wounds were sprayed with cultured autologous keratinocytes suspended in 1ml of the fibrin/aprotinin component of Tisseel fibrin glue (Baxter) mixed with 1ml of culture medium. In the latter group the thrombin component of the fibrin glue kit was applied to the wound bed immediately prior to grafting. The remaining two wounds were used as controls and sprayed with either culture medium or fibrin glue without cells. Epithelial cover was calculated in whole-wound biopsies at 3 weeks using image analysis, histology and immunohistochemistry.The cell suspension in fibrin glue appeared to spread more evenly over the wound surface, with no pooling in the inferior aspect of the wound. However, mean epithelial area at 3 weeks in the fibrin group was 1.6cm(2) per wound compared with 1.8cm(2) for the non-fibrin group, as measured by image analysis of digital photographs. There was no statistically significant difference between the two groups (P=0.802). This surprising result was confirmed by histological analysis of the wound biopsies, with a good correlation between histological and image analysis data (R=0.967). There was no observable difference in the quality of the epithelium on histological and immunohistological analysis of either group.     

Dermal fibroblasts do not enhance the graft take rate of autologous, cultured keratinocyte suspension on full-thickness wounds in rats

Dermal fibroblasts are known to play an important role in wound healing. In this study, cultured autologous keratinocyte suspension was applied with fibrin glue to the full-thickness wounds in rats (N = 20). Histological analysis on day 14 showed regenerated epithelium in 10 wounds (50%). Keratinocytes were also premixed with allogeneic dermal fibroblasts in a ratio of 3:1 and 5:1 before application to other full-thickness wounds (N = 20) with fibrin glue. Regeneration of epithelium was observed in 10 (50%) and 9 (45%) wounds respectively. Acute inflammatory reaction and mild to moderate proliferation of fibroblasts in the subepithelial layer of the allogeneic fibroblasts were noted. The addition of dermal fibroblasts to keratinocytes/fibrin glue does not enhance the take rate of the cultured keratinocyte suspension.     

自体表皮细胞-纤维蛋白膜创面移植治疗大鼠烧伤

目的：观察自体表皮细胞-纤维蛋白膜移植到大鼠烧伤创面治疗皮肤缺损的效果。方法：健康Wistar大鼠20只,随机分成烧伤皮肤缺损造模组和自体表皮细胞-纤维蛋白膜移植治疗组,治疗后计算表皮细胞在纤维蛋白膜上最佳接种密度,观察移植后的各组创面愈合情况、创面伤口的收缩比例等。结果：在纤维蛋白膜上接种表皮细胞的最佳密度为5×10^4／cm2,烧伤皮肤缺损造模组创面完全愈合时间平均22．3d,自体表皮细胞-纤维蛋白膜移植治疗组为18．1d,造模组创面收缩率为（70±5）％,移植组为（20±5）％（均P〈0．05）。结论：自体表皮细胞-纤维蛋白膜可用于覆盖大面积烧伤造成的皮肤缺损,预防创面伤口瘢痕化的形成,减轻创面收缩率,加速皮肤缺损创面的愈合速度。     

Upward migration of cultured autologous keratinocytes in Integra artificial skin: a preliminary report.

The combination of cultured autologous keratinocytes with the dermal regeneration template Integra could offer increased possibilities for reconstructive surgery and wound healing. A single-step application of cells, centrifuged deep into an Integra-like matrix at the silicone-matrix junction, has been described but might prove technically complex for clinical use. We have investigated the possibility of simplifying this procedure by applying cultured cells directly to the underside of the Integra or directly to the wound bed immediately prior to grafting. The objective was to see whether cells would migrate through the matrix in an upward direction. We tested the principle of this concept using a pig wound healing model. Integra was seeded directly with cultured cells and grafted onto fresh full-thickness wounds, or unseeded Integra was applied to freshly excised wound beds that had just been seeded with the same number of cells. Biopsies were taken at 3, 7, 11, and 14 days. Histological sections showed that the cells moved through the Integra to give a confluent surface epithelium. Direct seeding onto the Integra was the most efficient method. Transduction of cultured autologous keratinocytes in vitro with a MFGlacZnls retrovirus confirmed that the epidermis was derived from the cultured autologous keratinocytes.     

Membrane cell grafts , fresh and frozen, to cover full thickness wounds in athymic nude mice

Biobrane, an adherent, flexible temporary wound dressing was incubated with cultured human keratinocytes. The cells adhered quickly, forming ”membrane-cell-grafts” (MCG). Some of the grafts were frozen and, after thawing, viability was verified with an XTT colorimetric assay. MCGs, fresh and cryopreserved, were transplanted on full thickness wounds created on athymic nude mice and resulted in a differentiated epithelium of human phenotype. For further investigation immunohistochemistry, immunofluorescence and electronmicroscopy were performed. Conventional cultured epidermal grafts (CEG) and wounds without cell grafts served as control. Compared with CEG-grafted sites a reduced wound contraction was noticed and complete remodelling of the basement membrane zone was found. The effectiveness of the easy, uncomplicated production, cryopreservation and use, as well as the short culture period could lead to a new approach in the treatment of burns and chronic wounds. Received: 12 February 1998 / Accepted: 2 February 1999     

Autologous cultured keratinocytes on porcine gelatin microbeads effectively heal chronic venous leg ulcers.

We have established a specific bioreactor microcarrier cell culture system using porcine gelatin microbeads as carriers to produce autologous keratinocytes on a large scale. Moreover, we have shown that autologous keratinocytes can be cultured on porcine collagen pads, thereby forming a single cell layer. The objective of this study was to compare efficacy and safety of autologous cultured keratinocytes on microbeads and collagen pads in the treatment of chronic wounds. Fifteen patients with recalcitrant venous leg ulcers were assigned to three groups in a single-center, prospective, uncontrolled study: five underwent a single treatment with keratinocyte monolayers on collagen pads (group 1); another five received a single grafting with keratinocyte-microbeads (group 2); and the last five received multiple, consecutive applications of keratinocyte-microbeads 3 days apart (group 3). All patients were followed for up to 12 weeks. By 12 weeks, there was a mean reduction in the initial wound area of 50, 83, and 97 percent in the three groups, respectively. The changes in wound size were statistically significant between the first and third groups (p= 0.0003). Keratinocyte-microbeads proved to be more effective than keratinocyte monolayers on collagen pads when the former were applied every 3 days. Rapid availability within 10-13 days after skin biopsy and easy handling represent particular advantages.     

Skin wound closure in athymic mice with cultured human cells, biopolymers, and growth factors

Skin wound closure remains a major problem in acute and reconstructive skin grafting after large burns because of limited availability of donor skin. This report evaluates six protocols for preparation in vitro of skin substitutes composed of cultured human cells, biopolymers, and growth factors for wound closure. Full-thickness wounds in athymic mice treated in a single procedure with cultured skin substitutes were compared directly to treatments with murine skin autograft, human skin xenograft, or no graft. Rectilinear planimetry of healed wounds 6 weeks after surgery showed that skin substitutes cultured in serum-free medium, and for 24 hours before surgery in defined medium with basic fibroblast growth factor (100 ng/ml), were not statistically different (p less than 0.05) in size from treatment with human skin xenograft. Acceptance and persistence of skin substitutes cultured in serum-free media were 70% at 6 weeks after surgery, as determined by staining of healed skin with a fluorescein-labeled monoclonal antibody against human HLA-ABC antigens. Ultrastructural examination of wounds with cultured human skin 6 weeks after treatment showed complete basement membrane, including anchoring fibrils, presence of melanocytes and pigment transfer to keratinocytes, and innervation of healed skin adjacent to basement membrane. These findings demonstrate effectiveness of cultured skin substitutes for closure of skin wounds and illustrate important capabilities to modulate the natural processes of wound repair, to increase supply of materials used for wound repair, and to enhance quality of wound healing.     

Cultured epithelial autograft (CEA) in burn treatment: three decades later

Methods for handling burn wounds have changed in recent decades and increasingly aggressive surgical approach with early tangential excision and wound closure is being applied. Split-thickness skin (STSG) autografts are the "gold standard" for burn wound closure and remain the mainstay of treatment to provide permanent wound coverage and achieve healing. In some massively burned patients, however, the burns are so extensive that donor site availability is limited. Fortunately, considerable progress has been made in the culture of human keratinocytes and it is now possible to obtain large amounts of cultured epithelium from a small skin biopsy within 3-4 weeks. Questions related to optimal cell type for culture, culture techniques, transplantation of confluent sheets or non-confluent cells, immediate and late final take, carrier and transfer modality, as well as final outcome, ability to generate an epithelium after transplantation, and scar quality are still not fully answered. Progress accomplished since Reinwald and Green first described their keratinocyte culture technique is reviewed.     

Evaluation of autologous bone marrow‐derived nucleated cells for healing of full‐thickness skin wounds in rabbits

The aim of the study was to evaluate the potential of autologous bone marrow‐derived nucleated cells to enhance the rate of healing of full‐thickness excisional skin wounds in rabbits. The study was conducted on 20 New Zealand white rabbits of either sex. Two, 2 × 2 cm full‐thickness skin (thoracolumabar region) excisional wounds were created; one on each side of the dorsal midline in each animal. The wounds were randomly assigned to either injection of autologous bone marrow‐derived nucleated cells into the wound margins (BI), or topical application of sterile saline solution (normal saline, NS), which served as control. The wound healing was assessed by evaluation of granulation tissue formation, wound contraction, epithelisation and histopathological and histochemical changes up to 28 days after creation of the wound. Granulation tissue appeared significantly faster in BI‐treated wounds (3.22 ± 0.22 days) than in NS‐treated wounds (4.56 ± 0.47 days). Better epithelisation was seen histologically in BI wounds than in NS‐treated wounds. Wound contraction was significantly more in BI wounds when compared with NS wounds on 21 post‐surgery. Histopathological examination of the healing tissue showed early disappearance of inflammatory reaction, significantly more neovascularisation, and more fibroplasias and early lay down and histological maturation of collagen in BI wounds than in control wounds. It was concluded that injection of autologous bone marrow‐derived nucleated cells in the wound margins induced faster and better quality healing of excisional skin wounds in rabbits when compared with normal saline. The injection of autologous bone marrow‐derived nucleated cells can be used to promote healing of large full‐thickness skin wounds in rabbits.