Abstract Chronic wound healing is often impaired in conditions such as metabolic syndrome, requiring effective therapeutic interventions to promote tissue regeneration and repair. In this study, we evaluated the wound healing potential of petroleum jelly (P Jelly)-based bioactive glass ointments (PBGCu) with varying copper concentrations (0, 1, and 3 wt%) in both in vitro and in vivo models of wound healing. PBGCu formulations demonstrated high biocompatibility with human dermal fibroblasts (HDF) and human umbilical vein endothelial cells (HUVEC). Additionally, PBGCu ointments exhibited strong antibacterial activity against Staphylococcus aureus , suggesting their utility for the care of chronic wounds. In both metabolic syndrome mouse and pig models, PBGCu3-treated wounds showed significantly faster wound closure, enhanced epithelial regeneration, and increased dermal thickness compared to saline and P Jelly controls. Histological analysis also revealed 50% increased vascularization (p < 0.0001) and a 90% reduction in scar formation (p < 0.0001) in PBGCu3-treated wounds. These findings show that PBGCu formulations, especially at 3 wt% copper concentration, significantly improve wound healing by promoting epithelial regeneration, dermal tissue formation, and vascularization, while also offering antibacterial protection. The sustained Cu 2+ ions release from PBGCu ointments provides long-term support for tissue regeneration, positioning this ointment composition as a promising therapeutic tool for chronic wound management. Future studies will focus on elucidating the underlying mechanisms and evaluating the therapeutic efficacy of PBGCu formulations in infected wounds. Highlights Developed a Petroleum Jelly–based copper-doped bioactive glass ointment (PBGCu) enabling sustained and controlled Cu²⁺ ion release. PBGCu significantly accelerated wound closure and improved epithelial and dermal tissue regeneration. PBGCu enhanced hair follicle regeneration and tissue remodeling in full-thickness wounds. Validated therapeutic efficacy in both mouse and pig models that support translational relevance. Offers a simple, low-cost, and clinically adaptable topical formulation for metabolic syndrome-related wound complications.

Capabilities for quantitative monitoring of chronic wounds remain an unmet clinical need, as existing diagnostic approaches rely on semiquantitative evaluation of symptoms that lack sensitivity especially during early stages of infection. Here we present a scheme for tracking wound physiology that leverages a miniature, wireless skin-interfaced device for non-contact, transient measurements of the flux of volatile organic compounds (VOCs) and water vapor from the wound microenvironment. Unlike emerging smart bandage platforms that rely on physical contact with the fragile wound bed to interrogate liquid-phase biomarkers, this strategy uses an engineered microclimate and suspended suite of sensors to measure the diffusive transport of wound-derived gases across the wound surface but separated from it. The result enables quantitative evaluation of metabolic activity and healing progression without perturbing the healing tissues. In biofilm growth models of Staphylococcus aureus, measurements demonstrate that trends in VOC flux correlate strongly with bacterial growth kinetics and precede any visible biofilm formation. Longitudinal monitoring in infected murine wound healing models shows that concurrent measurements of water vapor and VOC flux provide complementary physiological insights, capturing both the trajectory of barrier restoration and the dynamics of bacterial burden. The findings establish this non-contact sensing scheme as a distinct and clinically translatable paradigm for wound monitoring, with broad implications for non-invasive surveillance of disease states in which tissue metabolic activity and skin barrier integrity serve as actionable physiological readouts.

Traumatic cranial defects often involve concurrent loss of soft and hard tissues and can progress to chronic defects due to delayed healing associated with infection or other co-morbidities. Despite autologous reconstruction remaining the clinical standard, it requires staged procedures using heterogeneous tissues, increasing operative time, costs, and surgical risks. Moreover, current tissue engineering approaches focus on single tissues or acute tissue defect models, limiting their clinical applications. Herein, we describe an acellular, material-driven 3D-printed composite scaffold designed to regenerate both bone and skin within composite cranial defects. The scaffold integrates controlled copper ion release from both organic and inorganic components with 3D-printed citrate polymer and citrate polymer-ceramic composites. Integrated thermoresponsive citrate-based hydrogels further enable spatially defined dermoconductive and osteoconductive properties, supporting a one-step surgical approach. At 12 weeks post-implantation, our scaffold enhanced keratinocyte organization, collagen deposition, and defect coverage with mature bone, achieving histological outcomes comparable to autografts. Furthermore, the system suppressed bacterial burden. Thus, this acellular platform represents a clinically promising synchronized strategy to address the complex demands of traumatic craniofacial composite defects.

Diabetic wounds exhibit impaired immune function, delayed neutrophils recruitment, and heightened infection risk which compromises early infection control and delays healing. We have demonstrated that topical CCL3 treatment restores neutrophil influx, reduces bacterial infection by ~99%, and accelerates wound healing in diabetic mice. As per Food and Drug Administration (FDA) Guidelines for Investigational New Drug (IND), we conducted a 14-day acute toxicity study in diabetic mice following a single topical administration of CCL3 at effective low dose (1 µg) and high dose (10 µg) per wound. Mice were monitored for clinical signs, body weight, and food intake throughout the study period. On day 14, serum biochemistry (ALT, AST, BUN, creatinine, metabolic markers) and histopathology of major organs (liver, kidney, heart, lungs, spleen) were assessed. CCL3-treated diabetic mice exhibited no adverse clinical effects. Hematological and biochemical parameters remained within normal limits, and histopathological analyses revealed no additional organ injury in CCL3-treated groups compared to diabetic control mice. Intriguingly, CCL3-treated mice showed improved ALT levels and reduced hepatic pathology, suggesting hepatoprotective effects and reduced serum IgG, indicating reduced systemic inflammation. Overall, our study demonstrates that diabetic mice tolerate topical CCL3 at doses up to 10 times the effective therapeutic concentration without evidence of systemic organ toxicity. These findings provide strong preclinical support for the translational development of CCL3 as a novel therapy for diabetic wound care.

Critical limb ischemia (CLI), a severe complication of peripheral artery disease, presents a significant clinical challenge due to limited treatment options. Existing preclinical models of CLI frequently neglect biological variables such as age and sex, limiting their capacity to effectively assess novel therapies. This study seeks to address the deficiencies in the widely used murine hindlimb ischemia model for CLI by examining the influence of age and sex on recovery outcomes. Foxn1nu mice with varying age and biological sex were subjected to femoral artery ligation to establish unilateral hindlimb ischemia. Hindlimb perfusion was measured on multiple post-surgery days using Laser Doppler Imaging. Motor function and tissue damage were recorded through gross examination. Gastrocnemius muscles, collected on postsurgical day 36, underwent vascular and muscular histological analysis. All parameters were compared across age and sex groups. Mature adult mice (12–18 weeks old) consistently exhibited significantly heightened motor function impairment and tissue loss, with significantly slower perfusion recovery, in comparison to their younger counterparts (6–12 weeks old). Sexual dimorphism manifested, with females experiencing more pronounced symptoms than males. Histological analysis revealed skeletal muscle pathology in mature adults, similar to the clinical pathology of CLI, including muscle fiber loss, fibrosis, and adipose-like tissue infiltration. Animals of older age and female biological sex exhibited slower vascular regeneration. Age and biological sex significantly influence tissue recovery in the murine hindlimb ischemia model. To better evaluate pro-regenerative therapeutics for CLI, the utilization of older, mixed-sex mice in preclinical studies is recommended. This study underscores the critical impact of age and biological sex on tissue response in the murine hindlimb ischemia model. When evaluating both male and female mice across two distinct age groups, the older female group is significantly associated with worse outcomes in blood perfusion recovery, ambulatory function, tissue loss, and muscular and vascular characteristics. These findings strongly advocate for the use of mature adult mice with mixed biological sex in preclinical investigations. This comprehensive characterization and validation of a widely employed preclinical model significantly enhances the outcome’s credibility while evaluating pro-regenerative therapies for the treatment of critical limb ischemia.

Nuclear morphology plays a critical role in regulating gene expression and cell functions. While most research has focused on the direct effects of nuclear morphology on cell fate, its impact on the cell secretome and surrounding cells remains largely unexplored. In this study, we fabricate implants with a micropillar topography using methacrylated poly(octamethylene citrate)/hydroxyapatite (mPOC/HA) composites to investigate how micropillar-induced nuclear deformation influences cell secretome for osteogenesis and cranial bone regeneration. In vitro, cells with deformed nuclei show enhanced secretion of proteins that support extracellular matrix (ECM) organization, which promotes osteogenic differentiation in neighboring mesenchymal stromal cells (MSCs). In a female mouse model with critical-size cranial defects, nuclear-deformed MSCs on micropillar mPOC/HA implants elevate Col1a2 expression, contributing to bone matrix formation, and drive cell differentiation toward osteogenic progenitor cells. These findings indicate that micropillars modulate the secretome of hMSCs, thereby influencing the fate of surrounding cells through matricrine effects.

Existing wearable technologies rely on physical coupling to the body to establish optical1,2, fluidic3,4, thermal5,6 and/or mechanical7,8 measurement interfaces. Here we present a class of wearable device platforms that instead relies on physical decoupling to define an enclosed chamber immediately adjacent to the skin surface. Streams of vapourized molecular substances that pass out of or into the skin alter the properties of the microclimate defined in this chamber in ways that can be precisely quantified using an integrated collection of wireless sensors. A programmable, bistable valve dynamically controls access to the surrounding environment, thereby creating a transient response that can be quantitatively related to the inward and outward fluxes of the targeted species by analysing the time-dependent readings from the sensors. The systems reported here offer unique capabilities in measuring the flux of water vapour, volatile organic compounds and carbon dioxide from various locations on the body, each with distinct relevance to clinical care and/or exposure to hazardous vapours. Studies of healing processes associated with dermal wounds in models of healthy and diabetic mice and of responses in models using infected wounds reveal characteristic flux variations that provide important insights, particularly in scenarios in which the non-contact operation of the devices avoids potential damage to fragile tissues.

Highly elastic and 3D-printable degradable elastomers are advantageous for many biomedical applications. Herein, we report the synthesis of a biodegradable citrate rubber poly(tetrahydrofuran-co-citrate-co-hydroxyl telechelic natural rubber) (PTCR) using citric acid, poly(tetrahydrofuran), and hydroxyl telechelic natural rubber. The citrate rubber PTCR is methacrylated to synthesize a prepolymer methacrylated-PTCR (mPTCR) that can be used to fabricate bioresorbable scaffolds via 3D printing using micro-continuous liquid interface production. Polymers were chemically characterized via NMR spectroscopy, FTIR spectroscopy, DSC, and TGA and mechanically characterized via tensile testing and crimping. The addition of rubber improved the elasticity of PTCR (658 ± 68% for dry and 415 ± 45% for swollen films) significantly compared with its nonrubber-based citrate copolymer, i.e., poly(tetrahydrofuran-co-citrate) (PTC) (550 ± 51% for dry and 88 ± 10% for swollen films). Also, the mechanical strength of PTCR reached as high as 0.8 ± 0.06 MPa after the successful addition of rubber into PTC, which had a tensile strength of 0.55 ± 0.04 MPa. Notably, the 3D-printed vascular scaffold of mPTCR demonstrated excellent mechanical competence in crimping and expansion, which is necessary for clinical use. The percent diameter recovery of mPTCR vascular scaffolds (89.4 ± 1.1%) was higher than that of its nonrubber version, i.e., methacrylated-poly(tetrahydrofuran-co-citrate) (mPTC) (77.2 ± 6.7%), illustrating the contribution of rubber in mPTCR. In vitro degradation studies showed rapid hydrolytic degradation of the PTCR elastomer in 6 weeks, whereas 3D-printed scaffolds of mPTCR degraded slowly due to its improved stability after methacrylation. The cytocompatibility and cell attachment on the vascular scaffold surfaces were successfully demonstrated by using L929 mouse myoblasts. To conclude, this study reports a citrate-based rubber that should help meet some of the scaffold mechanical requirements for tissue-engineering applications.

Cancer cells exhibit a remarkable resilience to cytotoxic stress, often adapting through transcriptional changes linked to alterations in chromatin structure. In several types of cancer, these adaptations involve epigenetic modifications and restructuring of topologically associating domains. However, the underlying principles by which chromatin architecture facilitates such adaptability across different cancers remain poorly understood. To investigate the role of chromatin in this process, we developed a physics-based model that connects chromatin organization to cell fate decisions, such as survival following chemotherapy. Our model builds on the observation that chromatin forms packing domains, which influence transcriptional activity through macromolecular crowding. The model accurately predicts chemoevasion in vitro, suggesting that changes in packing domains affect the likelihood of survival. Consistent results across diverse cancer types indicate that the model captures fundamental principles of chromatin-mediated adaptation, independent of the specific cancer or chemotherapy mechanisms involved. Based on these insights, we hypothesized that compounds capable of modulating packing domains, termed Transcriptional Plasticity Regulators (TPRs), could prevent cellular adaptation to chemotherapy. We conducted a proof-of-concept compound screen using live-cell chromatin imaging to identify several TPRs that synergistically enhanced chemotherapy-induced cell death. The most effective TPR significantly improved therapeutic outcomes in a patient-derived xenograft model of ovarian cancer. These findings underscore the central role of chromatin in cellular adaptation to cytotoxic stress and present a framework for enhancing cancer therapies, with broad potential across multiple cancer types.

Ultraviolet (UV) radiation is a major contributor to skin damage, leading to oxidative stress, DNA damage, and apoptosis. Developing effective photoprotective agents that mitigate UV radiation-induced cellular and molecular damage is crucial for advancing skincare solutions. This study investigates the photoprotective and antioxidative properties of panthenol citrate (PC) using an ex vivo human skin organ model. PC demonstrated robust antioxidative activity, effectively scavenging free radicals, chelating iron ions, and inhibiting lipid peroxidation, with efficacy comparable to or exceeding that of l-ascorbic acid (Vitamin C). PC treatment significantly reduced UV radiation-induced DNA damage, as confirmed by decreased 8-OHdG staining and inhibited apoptosis, evidenced by lower levels of caspase-3-positive cells. Histological analysis revealed that PC preserved skin structure and reduced pyknotic nuclei caused by UV radiation exposure. Importantly, these protective effects were observed across both hydrophilic (glycerol) and hydrophobic (coconut oil) carriers, highlighting PC's versatility for formulation development. Collectively, these findings establish PC as a multifunctional photoprotective agent with significant potential for mitigating UV radiation-induced oxidative stress and promoting skin health. This study paves the way for the incorporation of PC into advanced skincare formulations to enhance UV radiation protection.

Non-healing chronic wounds in diabetic patients pose a significant health and economic burden. We have previously shown that the citrate-based thermoresponsive macromolecule poly(polyethylene glycol citrate-co–N-isopropylacrylamide) displaying the laminin-derived peptide A5G81 (A5G81-PPCN) accelerates wound closure when used as a regenerative dressing in diabetic mice. Although results are promising, A5G81-PPCN should be evaluated in a relevant large animal model of impaired wound healing. While several large animal models of impaired wound healing have been reported, the Ossabaw miniature swine is unique because it exhibits the full spectrum of metabolic syndrome features and vascular complications that are most similar to those of humans. In this study we investigated whether alloxan-induced diabetic Ossabaw miniature swine would manifest impaired wound healing similar to that observed in humans and evaluated the efficacy and safety of A5G81-PPCN, PPCN, and the commercial dressing Promogran Prisma™. After at least 5 months of hyperglycemia (≥ 200 mg/dL) eight full-thickness wounds (3 cm × 3 cm × 5 mm) were created on the back of each animal. Weekly dressing changes, treatment reapplications, and monitoring of blood glucose and weight were performed for 8 weeks post-wounding. Diabetic Ossabaw swine exhibited notable delayed healing compared to non-diabetic counterparts, validating the model’s relevance. Moreover, PPCN and A5G81-PPCN exhibited accelerated wound closure rates relative to Promogran Prisma™. This research underscores the potential for this citrate-based thermoresponsive macromolecule to address an unmet clinical need for healing wounds in diabetic patients and highlights Ossabaw swine as a new model for studying impaired wound healing in diabetes. Non-healing chronic wounds in diabetic patients pose a significant health and economic burden. We previously developed a unique regenerative dressing called A5G81-PPCN, made from a temperature-sensitive material with a peptide component that accelerates wound healing in diabetic mice. To test this dressing in a clinically relevant model, we used Ossabaw miniature pigs, which mimic human metabolic syndrome and blood vessel complications. After inducing diabetes in these pigs, we created skin wounds and monitored healing for eight weeks. Results show that A5G81-PPCN and PPCN dressings accelerate wound closure relative to a commercial dressing, Promogran Prisma™. This research suggests that A5G81-PPCN could be a valuable new approach to help heal diabetic wounds and positions the Ossabaw pig as an important model for studying diabetic wound healing.

Tissue engineering heavily relies on cell-seeded scaffolds to support the complex biological and mechanical requirements of a target organ. However, in addition to safety and efficacy, translation of tissue engineering technology will depend on manufacturability, affordability, and ease of adoption. Therefore, there is a need to develop scalable biomaterial scaffolds with sufficient bioactivity to eliminate the need for exogenous cell seeding. Herein, we describe synthesis, characterization, and implementation of an electroactive biodegradable elastomer for urinary bladder tissue engineering. To create an electrically conductive and mechanically robust scaffold to support bladder tissue regeneration, we developed a phase-compatible functionalization method wherein the hydrophobic conductive polymer poly(3,4-ethylenedioxythiophene) (PEDOT) was polymerized in situ within a similarly hydrophobic citrate-based elastomer poly(octamethylene-citrate-co-octanol) (POCO) film. We demonstrate the efficacy of this film as a scaffold for bladder augmentation in athymic rats, comparing PEDOT-POCO scaffolds to mesenchymal stromal cell-seeded POCO scaffolds. PEDOT-POCO recovered bladder function and anatomical structure comparably to the cell-seeded POCO scaffolds and significantly better than non-cell seeded POCO scaffolds. This manuscript reports: (1) a new phase-compatible functionalization method that confers electroactivity to a biodegradable elastic scaffold, and (2) the successful restoration of the anatomy and function of an organ using a cell-free electroactive scaffold.

Chronic bladder dysfunction due to bladder disease or trauma is detrimental to affected patients as it can lead to increased risk of upper urinary tract dysfunction. Current treatment options include surgical intervention that enlarge the bladder with autologous bowel tissue to alleviate pressure on the upper urinary tract. This highly invasive procedure, termed bladder augmentation enterocystoplasty (BAE), significantly increases risk of patient morbidity and mortality due to the incompatibility between the bowel and bladder tissue. Therefore, patients would significantly benefit from an alternative treatment strategy that can regenerate healthy tissue and restore overall bladder function. Previous research has demonstrated the potential of citrate-based scaffolds co-seeded with bone marrow-derived stem/progenitor cells as an alternative graft for bladder augmentation. Recognizing that contact guidance is known to influence tissue regeneration, we hypothesized that patterned scaffolds would modulate cell responses and improve overall quality of the regenerated bladder tissue. We fabricated microgrooved (MG) scaffolds using citrate-based biomaterial poly(1,8-octamethylene-citrate-co-octanol) (POCO) and co-seeded them with human bone marrow derived mesenchymal stem cells (MSCs) and CD34+ hematopoietic stem/progenitor cells (HSPCs). Microgrooved POCO scaffolds supported MSC and HSPC attachment, and MSC alignment within the microgrooves. All scaffolds were characterized and assessed for bladder tissue regeneration in an established nude rat bladder augmentation model. In all cases, normal physiological function was maintained post-augmentation, even without the presence of stem/progenitor cells. Urodynamic testing at 4-weeks post-augmentation for all experimental groups demonstrated that capacity increased and compliance was normal. Histological evaluation of the regenerated tissue revealed that cell-seeded scaffolds restored normal bladder smooth muscle content and resulted in increased revascularization and peripheral nerve regeneration. The presence of microgrooves on the cell-seeded scaffolds increased microvasculature formation by 20% and urothelium layer thickness by 25% in the regenerating tissue. Thus, this work demonstrates that micropatterning affects bladder regeneration to improve overall anatomical structure and re-establish bladder physiology.

Clinical outcomes for total-pancreatectomy followed by intraportal islet autotransplantation (TP-IAT) to treat chronic pancreatitis (CP) are suboptimal due to pancreas inflammation, oxidative stress during islet isolation, and harsh engraftment conditions in the liver’s vasculature. We describe a thermoresponsive, antioxidant macromolecule poly(polyethylene glycol citrate- co - N -isopropylacrylamide) (PPCN) to protect islet redox status and function and to enable extrahepatic omentum islet engraftment. PPCN solution transitions from a liquid to a hydrogel at body temperature. Islets entrapped in PPCN and exposed to oxidative stress remain functional and support long-term euglycemia, in contrast to islets entrapped in a plasma-thrombin biologic scaffold. In the nonhuman primate (NHP) omentum, PPCN is well-tolerated and mostly resorbed without fibrosis at 3 months after implantation. In NHPs, autologous omentum islet transplantation using PPCN restores normoglycemia with minimal exogenous insulin requirements for >100 days. This preclinical study supports TP-IAT with PPCN in patients with CP and highlights antioxidant properties as a mechanism for islet function preservation.

Effective repair of large bone defects through bone tissue engineering (BTE) remains an unmet clinical challenge. Successful BTE requires optimal and synergistic interactions among biocompatible scaffolds, osteogenic factors, and osteoprogenitors to form a highly vascularized microenvironment for bone regeneration and osseointegration. We sought to develop a highly effective BTE system by using 3D printed citrate-based mPOC/hydroxyapatite (HA) composites laden with BMP9-stimulated human urine stem cells (USCs). Specifically, we synthesized and characterized methacrylate poly(1,8 octamethylene citrate) (mPOC), mixed it with 0%, 40% or 60% HA (i.e., mPOC-0HA, mPOC-40HA, or mPOC-60HA), and fabricated composite scaffold via micro-continuous liquid interface production (μCLIP). The 3D-printed mPOC-HA composite scaffolds were compatible with human USCs that exhibited high osteogenic activity in vitro upon BMP9 stimulation. Subcutaneous implantation of mPOC-HA scaffolds laden with BMP9-stimulated USCs revealed effective bone formation in all three types of mPOC-HA composite scaffolds. Histologic evaluation revealed that the mPOC-60HA composite scaffold yielded the most mature bone, resembling native bone tissue with extensive scaffold-osteointegration. Collectively, these findings demonstrate that the citrate-based mPOC-60HA composite, human urine stem cells, and the potent osteogenic factor BMP9 constitute a desirable triad for effective bone tissue engineering.

Cancer cells exhibit a remarkable resilience to cytotoxic stress, often adapting through transcriptional changes linked to alterations in chromatin structure. In several types of cancer, these adaptations involve epigenetic modifications and restructuring of topologically associating domains (TADs). However, the underlying principles by which chromatin architecture facilitates such adaptability across different cancers remain poorly understood. To investigate the role of chromatin in this process, we developed a physics-based mechanistic model that connects chromatin organization to cell fate decisions, specifically survival following chemotherapy. Our model builds on the observation that chromatin forms packing domains, which influence transcriptional efficiency through macromolecular crowding. The model accurately predicts chemoevasion in vitro, suggesting that changes in packing domains affect the likelihood of survival. Consistent results across diverse cancer types indicate that the model captures fundamental principles of chromatin-mediated adaptation, independent of the specific cancer or chemotherapy mechanisms involved. Based on these insights, we hypothesized that compounds capable of modulating packing domains, termed Transcriptional Plasticity Regulators (TPRs), could prevent cellular adaptation to chemotherapy. Using live-cell chromatin imaging, we conducted a compound screen that identified several TPRs which synergistically enhanced chemotherapy-induced cell death. The most effective TPR significantly improved therapeutic outcomes in a patient-derived xenograft (PDX) model of ovarian cancer. These findings underscore the central role of chromatin in cellular adaptation to cytotoxic stress and present a novel framework for enhancing cancer therapies, with broad potential across multiple cancer types.

Conductive polymers (CPs) are widely studied for their ability to influence a myriad of tissue systems. While their mixed ionic/electronic conductivity is commonly considered the primary driver of these benefits, the mechanisms by which CPs influence cell fate remain unclear. In this study, CP-biomaterial interactions are investigated using collagen, due to its widespread prevalence throughout the body and in tissue engineering constructs. Collagen is functionalized with both electrostatically and covalently bound derivatives of the CP poly(3,4-ethylenedioxythiophene) (PEDOT) doped via backbone-tethered sulfonate groups, which enable high solubility and loading to the collagen biomatrix. Intrinsically doped scaffolds are compared to those incorporated with a commercially available PEDOT formulation, which is complexed with polyanionic polystyrene sulfonate (PSS). Low loadings of intrinsically doped PEDOT do not increase substrate conductivity compared to collagen alone, enabling separate investigation into CP loading and conductivity. Interestingly, higher PEDOT loading bolsters human mesenchymal stromal (hMSC) cell gene expression of Oct-4 and NANOG, which are key transcription factors regulating cell stemness. Conductive collagen composites with commercial PEDOT:PSS do not significantly affect the expression of these transcription factors in hMSCs. Furthermore, it is demonstrated that PEDOT regulates cellular fate independently from physical changes to the material but directly to the loading of the polymer.

Composite cranial defects have individual functional and aesthetic ramifications, as well as societal burden, while posing significant challenges for reconstructive surgeons. Single-stage composite reconstruction of these deformities entail complex surgeries that bear many short- and long-term risks and complications. Current research on composite scalp-cranial defects is sparse and one-dimensional, often focusing solely on bone or skin. Thus, there is an unmet need for a simple, clinically relevant composite defect model in rodents, where there is a challenge in averting healing of the skin component via secondary intention. By utilizing a customizable (3D-printed) wound obturator, the scalp wound can be rendered non-healing for a long period (more than 6 weeks), with the cranial defect patent. The wound obturator shows minimal biotoxicity and will not cause severe endocranium-granulation adhesion. This composite defect model effectively slowed the scalp healing process and preserved the cranial defect, embodying the characteristics of a “chronic composite defect”. In parallel, an autologous reconstruction model was established as the positive control. This positive control exhibited reproducible healing of the skin within 3 weeks with variable degrees of osseointegration, consistent with clinical practice. Both models provide a stable platform for subsequent research not only for composite tissue engineering and scaffold design but also for mechanistic studies of composite tissue healing.