Chronic non-healing ulcers remain a significant health challenge worldwide, impacting millions of patients and placing a heavy burden on healthcare systems. These ulcers, characterized by their inability to heal within the expected timeframe, are often caused by underlying conditions such as diabetes, venous insufficiency, or pressure injuries. The lack of effective treatment options leads to prolonged patient suffering, increased risk of infections, and high medical costs, making the development of innovative wound care solutions a critical need [1]. Skin grafting has been a cornerstone in the treatment of chronic wounds for decades. Autologous skin grafts, where a patient's own skin is harvested and transplanted, are considered the gold standard for wound coverage and healing. These grafts offer excellent biocompatibility and low risk of immune rejection, making them a preferred choice in many cases. However, limitations such as donor site morbidity, limited availability of healthy skin, and challenges in extensive or complex wounds underscore the need for alternative approaches [2]. Recent advancements in tissue engineering have introduced novel techniques, including 3D bio-printing, to address the limitations of traditional skin grafts. 3D bio-printing involves the layer- by-layer deposition of bio-inks containing living cells and biomaterials to create skin grafts that closely mimic the structure and function of natural skin. This technology holds immense potential to revolutionize wound care by providing customizable, scalable, and infection-resistant skin substitutes [3]. One of the primary advantages of 3D-printed skin grafts is their ability to reduce dependence on donor sites, especially in patients with extensive wounds or limited healthy skin. By using biocompatible materials and patient-specific cells, 3D bio-printing can create grafts tailored to individual needs, ensuring a better fit and integration with the wound bed. Additionally, the ability to incorporate antimicrobial agents into the grafts during fabrication offers a unique advantage in preventing infections and promoting faster healing [4]. Chronic wounds are particularly prone to infections due to their prolonged exposure to environmental pathogens and impaired immune response. Infections not only delay wound healing but can also lead to severe complications such as sepsis or amputations. Traditional skin grafts, despite their benefits, are not immune to infections. In contrast, 3D-printed skin grafts have shown promising results in preclinical studies by reducing bacterial colonization and improving wound healing outcomes, though further clinical validation is necessary [5]. Another critical factor in the success of any wound treatment is the duration of healing. Faster wound closure not only minimizes the risk of complications but also improves the patient’s quality of life and reduces healthcare costs. While autologous skin grafts are effective, the advent of 3D-printed skin grafts offers a new horizon for achieving even shorter healing times due to their enhanced integration and regenerative capabilities. However, comparative data between these two methods remain limited, necessitating further research [6]. The application of 3D bio-printing in clinical settings is not without challenges. High costs, the need for skilled personnel, regulatory hurdles, and limited availability of bio-printers are some of the barriers to its widespread adoption. Despite these challenges, the rapid advancements in this field and the growing evidence of its efficacy suggest that 3D-printed skin grafts could become a game-changer in wound care within the next decade [7]. Several studies have highlighted the potential of 3D-printed skin grafts in promoting re- epithelialization, angiogenesis, and tissue regeneration in chronic wounds. These findings emphasize the importance of conducting comparative studies with traditional methods to establish their clinical superiority. Such research could pave the way for integrating 3D bio-printing into standard wound care protocols, benefiting a larger patient population [8]. The adoption of 3D-printed skin grafts has broader implications for healthcare systems, including the potential to reduce hospital stays, minimize the need for secondary surgeries, and improve cost-effectiveness. By addressing the challenges of chronic wound management, this technology could significantly improve patient outcomes and alleviate the burden on healthcare providers. Further research into its long-term effectiveness and scalability will be essential for achieving these goals [9,10]. The above study aims to evaluate the role of 3D-printed skin grafts in comparison with autologous skin grafts, focusing on the duration of wound healing and protection against infections. By analyzing and comparing these parameters, the study seeks to provide insights into the efficacy, safety, and practicality of using 3D-printed skin grafts for chronic non-healing ulcers, potentially paving the way for improved patient care and innovative treatment approaches.

The study was conducted at the Department of Surgery, Dr. D.Y. Patil Medical College, Hospital, and Research Institute, Kolhapur. from April 2023 to February 2025 after obtaining approval from the Institutional Ethics Committee A total of 52 patients (26 patients in each group) were included for the study. Inclusion Criteria Patients with non-healing ulcers measuring up to 10 cm in the longest diameter, undergoing skin grafting surgeries for lower limb wounds and aged 18 years and above. Exclusion Criteria Patients with immunodeficiency states such as HIV or malignancy and those who did not provide written informed consent to participate in the study. Participants were divided into two groups: one undergoing 3D-printed skin grafting and the other receiving autologous skin grafts. Both groups were managed with standard care protocols for wound preparation, graft application, and postoperative monitoring. The comparison allowed for the evaluation of healing duration, infection rates, and graft acceptance between the two methods. Group assignment was based on clinical suitability, patient preference, and availability of resources, ensuring that the study's observational nature was maintained. Patients underwent a thorough clinical examination and routine laboratory investigations, including complete blood count, fasting and postprandial glucose levels, and HbA1C. Wound bed preparation involved debridement and cleaning before graft application. For the 3D-printed group, wound dimensions were scanned using a 3D scanner, and customized skin scaffolds were fabricated. Autologous grafts were harvested from donor sites. Grafts were secured with dressings, which were changed on days 3, 5, and 7. Progress was monitored through clinical assessments. Graft success was defined by its retention for 10-15 days and complete epithelialization. Data collection was conducted at multiple time points, starting from patient enrollment follow-up to the final visit. Statistical analysis was performed using SPSS software.

Table 1: Graft Take Assessment by Type of Skin Graft Applied Graft Take Assessment Type of Skin Graft Applied 3D Skin Autologous Total Fully taken 10 21 31 19.23% 40.38% 59.62% Partially Taken 12 2 14 23.08% 3.85% 26.92% Rejected 4 3 7 7.69% 5.77% 13.46% Overall graft uptake was fully successful in 31/52 (59.62 %) patients: 10/26 (19.23 %) with 3D skin and 21/26 (40.38 %) with autologous grafts. Partially taken grafts occurred in 14/52 (26.92%): 12/26 (23.08 %) in the 3D group versus 2/26 (3.85 %) autologous. Rejection was noted in 7/52 (13.46 %): 4/26 (7.69 %) with 3D grafts and 3/26 (5.77 %) with autologous. Thus, autologous grafts achieved a higher rate of full take (21/26; 80.8 %) compared to 3D grafts (10/26; 38.5 %). Conversely, 3D grafts exhibited a greater proportion of partial takes (12/26; 46.2 %) and rejections (4/26; 15.4 %) than autologous grafts (2/26; 7.7 % partial, 3/26; 11.5 % rejected). Table 2: Complications Post Grafting by Type of Skin Graft Applied Complications Post Grafting Type of Skin Graft Applied 3D Skin Autologous Total No 13 15 28 25% 28.85% 53.85% Yes 13 11 24 25% 21.15% 46.15% Post‐grafting complications occurred in 24/52 (46.15 %) patients: 13/26 (25.00 %) in the 3D skin group and 11/26 (21.15 %) in the autologous group. The remainder 28/52 (53.85 %) were complication‐free: 13/26 (25.00 %) with 3D grafts and 15/26 (28.85 %) with autologous. Hence, equal numbers of 3D graft patients had complications as remained complication‐free (13/26; 50 %), whereas autologous recipients were slightly more often complication‐free (15/26; 57.7 %) than not (11/26; 42.3 %). Overall, the complication rate was comparable between groups, with a modestly higher proportion in the 3D cohort. Table 3: Wound Healing Status by Type of Skin Graft Applied Wound Healing Status Type of Skin Graft Applied 3D Skin Autologous Total Completely Healed 18 21 39 34.62% 40.38% 75% Not Healed 4 5 9 7.69% 9.62% 17.31% Partially healed 4 0 4 7.69% 0% 7.69% At final follow-up, 39/52 (75 %) achieved complete healing: 18/26 (34.62 %) with 3D grafts and 21/26 (40.38 %) with autologous grafts. Nine/52 (17.31 %) remained unhealed at study end: 4/26 (7.69 %) in the 3D group and 5/26 (9.62 %) in the autologous group. Four/52 (7.69 %) exhibited partial healing— each in the 3D group (4/26; 15.38 %), with none in the autologous group. Thus, complete healing was similar between autologous (21/26; 80.8 %) and 3D (18/26; 69.2 %). However, only 3D graft recipients showed partial healing (4/26; 15.4 %), whereas non-healing rates were comparable (3D: 4/26; 15.4 %, autologous: 5/26; 19.2 %).

Graft Take Assessment by Type of Skin Graft Applied Graft take was categorized as fully taken, partially taken, or rejected. Among 52 patients, 31 (59.62 %) achieved full take: 10/26 (38.46 %) in the 3D group and 21/26 (80.77 %) in the autologous group (p < 0.001). Partial takes occurred in 14/52 (26.92 %): 12/26 (46.15 %) 3D versus 2/26 (7.69 %) autologous (p < 0.001). Rejections were observed in 7/52 (13.46 %): 4/26 (15.38 %) 3D and 3/26 (11.54 %) autologous (p = 0.68). Thus, autologous grafts achieved a significantly higher full-take rate (80.8 % vs. 38.5 %), whereas 3D grafts had markedly more partial takes (46.2 % vs. 7.7 %). Yanez et al. (2015) reported that their murine 3D bilayer grafts achieved > 90 % integration in full-thickness wounds at day 14—conditions that do not directly mirror human ulcers but suggest that with an optimized model, 3D constructs can approach complete take if host perfusion is adequate [11]. Miyazaki et al. (2019) demonstrated that prevascularized 3D skin substitutes in mice achieved perfusion by day 7 and high survival rates, indicating that including endothelial networks can significantly enhance take—suggesting that our clinical 3D protocol might improve with analogous strategies [12]. Huyan et al. (2020) found that 10 % improvement in contraction with 3D bilayer grafts in murine wounds corresponded to near-complete neovascularization by day 10, implying that advanced scaffold design can minimize partial graft take [13]. Baltazar et al. (2020) showed that 3D vascularized grafts inosculated with host micro vessels within 4 weeks in mice, achieving > 85 % survival—reinforcing that engineered vascularization is key to matching autologous graft take rates [14]. In human trials, Fu et al. (2023) documented that 3D-printed dECM/methacrylated gelatin/hyaluronic acid constructs had a 75 % full-take rate in chronic murine wounds—suggesting incremental improvements in clinical 3D performance with advanced biomaterials [15]. In contrast, Martinez et al. (2016) achieved a 75.15 % (± 23.03) reduction in ulcer area using autologous hair follicle punch grafts, but did not explicitly quantify take; clinical experience indicates > 80 % full take for STSG in optimized beds [16]. Serra et al. (2017) confirmed that STSG‘s > 80 % success in venous ulcers relies on robust integration, which is difficult for acellular or non-vascularized scaffolds to match [17]. Taken together, our data demonstrate that while 3D constructs currently lag behind autologous grafts in full take, engineering advances—particularly prevascularization—could close this gap, reducing partial take and rejection rates.Complications Post Grafting by Type of Skin Graft Applied Post-grafting complications occurred in 24/52 (46.15 %) patients: 13/26 (50 %) in the 3D group and 11/26 (42.31 %) in the autologous group. The remaining 28/52 (53.85 %) were complication-free: 13/26 (50 %) 3D and 15/26 (57.69 %) autologous. The overall complication rate was slightly higher in the 3D cohort (50 % vs. 42.3 %), but not statistically significant (p = 0.55). Common complications included seroma, hematoma, maceration, and partial graft loss. Yanez et al. (2015) did not explicitly report complications in their murine model, but histological analysis showed minimal inflammation around 3D grafts, implying low complication rates under ideal conditions [11]. Miyazaki et al. (2019) found that prevascularized 3D grafts in mice had lower rates of central necrosis and infection compared to non-vascularized constructs, suggesting that incorporating vascular networks reduces complications—an approach our future protocols may adopt [12]. Huyan et al. (2020) reported robust angiogenesis and minimal inflammatory infiltrate in murine 3D bilayer grafts, but did not detail complications, likely reflecting the immunodeficient status of their model [13] . Baltazar et al. (2020) observed minimal graft contraction or necrosis in their vascularized 3D grafts in mice, indicating that pericyte inclusion can mitigate common complications [14]. In human contexts, Martinez et al. (2016) reported minimal donor-site morbidity but noted seroma formation in 16.7 % of autologous hair follicle recipients, indicating that autologous grafts also carry risks [16] . Serra et al. (2017) found that STSG in chronic leg ulcers incurred complication rates of 30–40 %—including partial graft loss and donor-site issues—consistent with our autologous complication rate of 42.3 % [17]. Fu et al. (2023) documented that 3D-printed dECM-based substitutes in murine models had < 10 % incidence of infection or necrosis—suggesting that optimized biomaterials can substantially reduce complications [15] . Schmitt et al. (2021) demonstrated high viability and metabolic activity in micro fat-laden constructs over 10 days, with a progressive cytokine profile conducive to healing, implying reduced inflammatory complications [18]. Sharma et al. (2024) indicated that 3D-printed dressings decreased complication rates by 20 % compared to traditional grafts in chronic wounds, reflecting the potential of engineered scaffolds to minimize adverse events [19] . Our comparable complication rates between 3D and autologous grafts suggest that, in experienced hands with standardized postoperative care, bio printed constructs can approach the safety profile of established auto grafts—though vigilance for seroma and partial take remains crucial. Wound Healing Status by Type of Skin Graft Applied At final follow-up (8–12 weeks), 39/52 (75 %) patients achieved complete wound healing: 18/26 (69.23 %) in the 3D group and 21/26 (80.77 %) in the autologous group. Nine/52 (17.31 %) remained unhealed: 4/26 (15.38 %) in 3D versus 5/26 (19.23 %) in autologous (p = 0.71). Partial healing was observed in 4/52 (7.69 %), exclusively among 3D recipients (4/26; 15.38 %). Thus, autologous grafts had a higher complete healing rate (80.8 % vs. 69.2 %; p = 0.27), with no cases of partial healing. Yanez et al. (2015) reported that in murine full-thickness wounds, 3D bilayer grafts achieved histologically complete skin regeneration—mimicking native epidermis and dermis by day 21—indicating potential for complete healing in smaller animal models [11]. Martinez et al. (2016) demonstrated that autologous hair follicle punch grafts achieved a 75.15 % (± 23.03) reduction in ulcer area over 18 weeks, with 80 % of patients attaining complete closure by week 18, supporting our autologous healing rates [16] . Serra et al. (2017) found that STSG in chronic leg ulcers yielded > 80 % closure by 12 weeks—paralleling our 80.8 % complete healing in the autologous cohort [17]. Miyazaki et al. (2019) showed that prevascularized 3D skin constructs achieved > 90 % survival and complete epidermal integration by day 28 in mice, suggesting that advanced 3D grafts can approach autologous outcomes under optimal conditions [12]. Huyan et al. (2020) observed a 10 % improvement in contraction and near-complete epithelialization by day 21 in murine 3D bilayer grafts, implying that clinical 3D constructs may require additional time or enhancements to match autologous closure rates in humans [13]. Baltazar et al. (2020) documented that vascularized 3D grafts in mice became perfused within 4 weeks and displayed mature epidermal‐dermal architecture by 6 weeks, indicating that integrating pericytes and endothelial cells could further elevate 3D healing rates [14]. Fu et al. (2023) reported that 3D-printed dECM/gelatin/hyaluronic acid substitutes accelerated re-epithelialization in murine models, achieving > 85 % closure by day 28, suggesting near-parity with autologous techniques when biomaterial composition is optimized [15]. Sharma et al. (2024) reviewed that 3D-printed dressings and grafts reduced healing time by 30 % versus conventional methods, indicating that future 3D constructs may surpass current clinical results [19]. In our cohort, the presence of partial healing exclusively in the 3D group (15.4 %) underscores that while many engineered grafts can approach closure, some require extended durations or secondary interventions to achieve full healing, unlike autologous grafts which yield more binary outcomes.

From the above study we can conclude that clinicians should anticipate prolonged dressing needs and heightened infection surveillance in 3D graft recipients, implementing occlusive or semi‐occlusive dressings for up to 7–10 days and incorporating prophylactic antimicrobial strategies within bio inks where possible. Histological monitoring at two and six weeks should be routine for 3D grafts to confirm integration, whereas autologous grafts can often rely on clinical inspection after 4 days. While autologous grafts currently offer higher reliability, the rapid evolution of bio-printing—including prevascularization, microfat integration, oxygen‐releasing particles, and antimicrobial additives—foreshadows near‐term improvements that may close the current performance gap. Continued investment in randomized controlled trials, rigorous histomorphometry, long‐term functional assessments, and cost‐effectiveness analyses will be pivotal to validate and refine 3D bio-printing as a mainstream wound‐care modality. With these innovations, future 3D‐printed skin constructs hold the potential not only to match autologous graft outcomes but also to surpass them by offering fully customized, vascularized, and immune compatible solutions that minimize donor‐site morbidity and expand treatment options for patients with recalcitrant or complex wounds.

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