Search Results (476)

Background/Objectives: Chemically or genetically detoxified pertussis toxin (PTx) is a crucial antigen component of the acellular pertussis vaccine. Chemical detoxification using glutaraldehyde generally causes significant structural changes to the toxin. However, how these structural changes in PTx affect its antigenic properties remains unclear. Additionally, there is limited knowledge regarding how many alterations in antigenic properties impact immunogenicity. Methods: To investigate the impact of structural changes on antigenic properties, we developed a sandwich ELISA to quantify the neutralizing epitopes on PTx. Subsequently, we analyzed different PTx toxoid (PTd) preparations with the assay. Additionally, we assessed the immunogenicity of various acellular pertussis vaccine candidates containing these PTd preparations. Finally, the assay was applied to evaluate the consistency of commercial batches of PTx and PTd intermediates. Results: The assay demonstrated reasonable specificity, accuracy, and precision, and it was sensitive enough to quantify variations in neutralizing epitopes among different PTd samples that shared the same protein concentration. Importantly, we found a positive correlation between the number of neutralizing epitopes in detoxified PTx and its immunogenicity, indicating that the amount of neutralizing epitopes present determines the immunogenicity of glutaraldehyde-inactivated PTx. Moreover, commercial batches of PTx and PTd intermediates exhibited minor variations in neutralizing epitopes. Conclusions: These findings have significant implications for developing acellular pertussis vaccines as they highlight the importance of preserving the neutralizing epitopes of PTx during detoxification to ensure the vaccine’s effectiveness. This assay is also valuable for the quality control of PTd as it more accurately represents the actual antigenic changes of PTx. Full article

This study characterized collagen remodeling in an electron-beam-sterilized porcine acellular dermal matrix (E-PADM) by evaluating host response kinetics during wound healing. E-PADM (n = 6 lots/time point) was implanted in an abdominal wall bridging defect in nonhuman primates (N = 24). Histological, immunohistochemical, and biochemical assessments were conducted. Pro-inflammatory tissue cytokines peaked 1 month post-implantation and subsided to baseline by 6 months. E-PADM-specific serum immunoglobulin G antibodies increased by 213-fold from baseline at 1 month, then decreased to <10-fold by 6–9 months. The mean percentage tissue area staining positively for matrix metalloproteinase-1 plateaued at 3 months (40.3 ± 16.9%), then subsided by 6 months (16.3 ± 11.1%); tissue inhibitor matrix metalloproteinase-1 content plateaued at 1 month (39.0 ± 14.3%), then subsided by 9 months (13.0 ± 8.8%). Mean E-PADM thickness (1.7 ± 0.2 mm pre-implant) increased at 3 months (2.9 ± 1.5 mm), then decreased by 9 months (1.9 ± 1.1; equivalent to pre-implant). Histology demonstrated mild inflammation between 1–3 months, then a peak in host tissue deposition, with ≈75%–100% E-PADM collagen turnover, and fibroblast infiltration and neovascularization between 3–6 months. Picrosirius red staining revealed that mature E-PADM collagen was replaced by host-associated neo-collagen by 6 months. E-PADM implantation induced wound healing, which drove dermal E-PADM collagen remodeling to native, functional fascia-like tissue at the implant site. Full article

Background and Clinical Significance: Breast reconstruction following mastectomy is a critical aspect of treatment for many patients, offering both physical and psychological benefits. Traditional methods include autologous tissue flaps and implants, with implant-based techniques being the most prevalent in the Western world. However, complications such as capsular contracture remain a concern. Acellular dermal matrices (ADM) have emerged as a valuable alternative, improving outcomes by reducing capsular contracture rates and enhancing tissue integration. Case Presentation: This case report presents the first use of a novel ADM, biocade^® (biotrics bioimplants AG, Berlin, Germany) in breast reconstruction following a mastectomy. A 55-year-old female patient underwent a left-sided nipple-sparing mastectomy, followed by prepectoral direct-to-implant reconstruction using an ADM-wrapped implant. The patient tolerated the procedure well, with no immediate complications observed. Postoperative monitoring focused on wound healing and assessing for signs of complications related to the implant. The use of the ADM resulted into satisfactory aesthetic and functional outcomes. Conclusions: The successful outcome of this case highlights the potential benefits of using collagen matrices in breast reconstruction, particularly in preserving mastectomy scenarios. The immediate results and improved aesthetics offered by prepectoral direct-to-implant reconstruction with ADM align well with patient expectations for a more natural appearance and faster recovery. However, this case report also highlights the need for ongoing research to fully explore the potential of these biomaterials and address associated challenges. Full article

Extracellular vesicles (EVs) have emerged as promising acellular tools for modulating immune responses for tissue engineering applications. This study explores the potential of human fibroblast-derived EVs delivered within a three-dimensional (3D) injectable scaffold composed of polycaprolactone (PCL) nanofibers and collagen (PNCOL) to reprogram macrophage behavior and support scaffold integrity under inflammatory conditions. EVs were successfully isolated from human fibroblasts using ultracentrifugation and characterized for purity, size distribution and surface markers (CD63 and CD9). Macrophage-laden PNCOL scaffolds were prepared under three conditions: macrophage-only (MP), fibroblast co-encapsulated (F-MP), and EV-encapsulated (EV-MP) groups. Structural integrity was assessed via scanning electron microscopy and Masson’s trichrome staining, while immunomodulatory effects were evaluated through metabolic assays, gene expression profiling, and immunohistochemistry for macrophage polarization markers (CD80, CD206). When co-encapsulated with pro-inflammatory (M1) macrophages in PNCOL scaffolds, fibroblast-derived EVs preserved scaffold structure and significantly enhanced macrophage metabolic activity compared to the control (MP) and other experimental group (F-MP). The gene expression and immunohistochemistry data demonstrated substantial upregulation of anti-inflammatory markers (TGF-β, CD163, and CCL18) and surface protein CD206, indicating a phenotypic shift toward M2-like macrophages for EV-encapsulated scaffolds relative to the other groups. The findings of this study demonstrate that fibroblast-derived EVs integrated into injectable PCL–collagen scaffolds offer a viable, cell-free approach to modulate inflammation, preserve scaffold structure, and support regenerative healing. This strategy holds significant promise for advancing immuno-instructive platforms in regenerative medicine, particularly in settings where conventional cell therapies face limitations in survival, cost, or safety. Full article

Burn wound infections remain a major clinical challenge due to delayed healing, scarring, and the risk of sepsis, especially when complicated by multidrug-resistant (MDR) Gram-negative pathogens and biofilm formation. Acellular dermal matrices (ADMs) are widely used in reconstructive and burn surgery, yet they lack intrinsic antimicrobial activity, necessitating their combination with topical agents. Background/Objectives: This study investigates the antimicrobial and cytocompatibility profiles of ADMs impregnated with various antimicrobial agents, using in vitro planktonic and biofilm burn wound models. While the incorporation of antimicrobials into scaffolds has been previously explored, this study is, to our knowledge, the first to directly compare seven clinically relevant antimicrobial agents after they were impregnated into an ADM in a standardized in vitro model. Methods: Seven topical antimicrobials were tested against MDR Pseudomonas aeruginosa and Acinetobacter baumannii from burn patients. Results: The ADM with 1% acetic acid (AA) showed superior antimicrobial activity, achieving > 7 log₁₀ reductions in planktonic assays and complete inhibition of P. aeruginosa biofilms. In NIH 3T3 fibroblast cytotoxicity assays, the 1% AA ADM maintained cell viability at control levels, indicating excellent biocompatibility. Compared with agents such as Betadine^®, Octenilin^®, and colistin, which showed cytotoxicity, and Prontosan^®, which showed low efficacy, 1% AA uniquely combined potent antibacterial effects with minimal toxicity. Conclusions: Among the seven antimicrobial agents impregnated into ADMs, 1% AA demonstrated a unique efficacy and safety profile, supporting its potential for clinical application in integrated wound dressings and implantable biomaterials for infection control in burn care. Full article

Background: The combined diphtheria–tetanus–acellular pertussis (three-component), Haemophilus influenzae type b (Hib, conjugate), and ACYW135 meningococcal (conjugate) vaccine (DTaP-Hib-MCV4) offers a promising alternative to single-component vaccines, potentially simplifying immunization schedules and improving vaccination coverage. Methods: We evaluated the safety, immunogenicity, and protective efficacy of DTaP-Hib-MCV4 in animal models. Acute and long-term toxicity studies were conducted in Sprague-Dawley (SD) rats with equal numbers of male and female animals. Immunogenicity was assessed in female NIH mice and SD rats using a three-dose regimen at 14-day intervals. Orbital blood was collected 14 days post-immunization to measure IgG titers against pertussis, diphtheria, tetanus, Hib, and meningococcal antigens. The protective efficacy was determined using potency tests for the pertussis, diphtheria, and tetanus components; passive protection studies for Hib; and serum bactericidal antibody (SBA) titers against A/C/Y/W135 meningococcal serogroups. Results: Acute and repeated-dose toxicity studies in SD rats showed no signs of abnormal toxicity or irritation at either high (three doses/rat) or low (one dose/rat) doses levels. The no-observed-adverse-effect level (NOAEL) for DTaP-Hib-MCV4 was established at three doses/rat after 8 weeks of repeated intramuscular administration and a 4-week recovery period. Specific IgG antibodies against all the vaccine components were detected in animal sera at both one and three doses/rat, with no evidence of immunotoxicity. Following two-dose primary immunization in murine models, the combined vaccine elicited robust antigen-specific antibody responses, with geometric mean titers (GMTs) as follows: 1,280,000 for pertussis toxin (PT); 761,093 for filamentous hemagglutinin (FHA); 1,159,326 for pertactin (PRN); 1,659,955 for diphtheria toxoid (DT); 1,522,185 for tetanus toxoid (TT); 99 for Haemophilus influenzae type b (Hib); and 25,600, 33,199, 8300, and 9051 for serogroups A, C, Y, and W135 of Neisseria meningitidis, respectively. In the rat models, three-dose primary immunization also elicited robust antigen-specific antibody responses. Protection studies demonstrated efficacy against pertussis, tetanus toxin, and diphtheria toxin challenges. In the Hib challenge study, none of the 10 animals given anti-DTaP-Hib-MCV4 antiserum developed bacteremia after the live Hib challenge (vs. 5814/0.1 mL in the negative control, p < 0.001). In addition, the SBA titers against meningococcal serogroups exceeded the protective threshold (≥1:8) in 92.2% of the immunized mice and 100% of the immunized rats. Crucially, the combined vaccine induced potent immune responses and protective efficacy, with antibody levels and protection against each component antigen comparable to or greater than those of the individual components: DTaP, Hib, and MCV4. Conclusions: These findings demonstrate that the DTaP-Hib-MCV4 combined vaccine is both safe and immunogenic, supporting its potential as a viable alternative to individual vaccines. This combined vaccine may streamline immunization programs and enhance vaccination coverage. Full article

Background and Objectives: Adequate soft tissue thickness and keratinized mucosa are essential for the long-term health and esthetics of the peri-implant area. A porcine acellular dermal matrix (PADM) has shown promise in augmenting soft tissue, but reliable fixation remains a challenge. Materials and Methods: This case series describes the use of a PADM fixed with resorbable magnesium screws (NOVAMag^®) in three patients requiring peri-implant soft tissue augmentation. The grafts were stabilized with magnesium screws on the buccal side. The clinical outcomes were evaluated over a period of 3–6 months using STL imaging and direct measurements. Results: All patients showed an improvement in their mucosal volume and keratinization. The mean vertical increase in soft tissue was 0.87 ± 0.16 mm and the mean horizontal increase was 1.00 ± 0.13 mm. The mucosal thickness increased from a baseline value of 1.0–1.2 mm to 1.9–2.1 mm, and the width of the keratinized mucosa improved by an average of 1.0 mm. No complications were observed, and in all cases there was tension-free healing and esthetic results. Conclusions: A PADM in combination with resorbable magnesium fixation screws offers a predictable and minimally invasive solution to improve peri-implant soft tissue with favourable short-term volumetric and esthetic results. Full article

Plasma, an ionized gas composed of charged particles, has shown therapeutic potential in enhancing biological processes such as wound healing and tissue integration. Implants, such as silicone and human acellular dermal matrix (hADM), are commonly used in reconstructive surgery, but improving their biocompatibility and integration remains a challenge. This study investigated the effects of vacuum plasma treatment on silicone and hADM implants using an in vivo rat model. Plasma-treated and untreated implants were inserted subcutaneously, and tissue samples were collected at 1, 4, and 8 weeks post-implantation. Histological and immunohistochemical analyses were performed to assess inflammation, cellular infiltration, collagen formation (neocollagenesis), and angiogenesis. Results showed that plasma-treated silicone and hADM implants had significantly reduced capsule thickness at weeks 4 and 8 compared to untreated controls, indicating a lower chronic inflammatory response. Plasma treatment also promoted greater fibroblast infiltration and enhanced neocollagenesis within the hADM implants. Furthermore, immunohistochemical staining revealed a notable increase in blood vessel formation around and within the plasma-treated hADM implants, suggesting improved vascularization. In conclusion, vacuum plasma treatment enhances the biocompatibility and tissue integration of implants by reducing inflammation and promoting cellular and vascular responses, offering promising potential for improving outcomes in reconstructive surgery. Full article

Several postmastectomy breast reconstruction techniques and procedures have been implemented, although with limited evaluation of benefits and adverse effects. We conducted a systematic review on the plane and timing of reconstruction, and on the use of nipple-sparing mastectomy, acellular dermal matrix, and autologous fat grafting as the evidence base for an updated clinical practice guideline on breast reconstruction for Ontario Health (Cancer Care Ontario). Both immediate and delayed reconstruction may be considered, with preferred timing depending on factors such as patient preferences, type of mastectomy, skin perfusion, comorbidities, pre-mastectomy breast size, and desired reconstructive breast size. Immediate reconstruction may provide greater psychological or quality of life benefits. In patients who are candidates for skin-sparing mastectomy and without clinical, radiological, and pathological indications of nipple-areolar complex involvement, nipple-sparing mastectomy is recommended provided it is technically feasible and acceptable aesthetic results can be achieved. Surgical factors including incision location are important to reduce necrosis by preserving blood supply and to minimize nerve damage. There is a role for both prepectoral and subpectoral implants; risks and benefits will vary, and decisions should be made during consultation between the patient and surgeons. In patients who are suitable candidates for implant reconstruction and have adequate mastectomy flap thickness and vascularity, prepectoral implants should be considered. Acellular dermal matrix (ADM) has led to an increased use of prepectoral reconstruction. ADM should not be used in case of poor mastectomy flap perfusion/ischemia that would otherwise be considered unsuitable for prepectoral reconstruction. Care should be taken in the selection and handling of acellular dermal matrix (ADM) to minimize risks of infection and seroma. Limited data from small studies suggest that prepectoral reconstruction without ADM may be feasible in some patients. Autologous fat grafting is recommended as a treatment for contour irregularities, rippling following implant-based reconstruction, and to improve tissue quality of the mastectomy flap after radiotherapy. Full article

Wound healing remains a significant clinical challenge worldwide, and effective management strategies are essential for improving outcomes. This study evaluated SCderm Matrix, a novel acellular dermal matrix (ADM) patch developed using supercritical carbon dioxide (sCO₂) processing of human skin tissue. This innovative processing method preserves structural integrity while enhancing biocompatibility, resulting in a patch characterized by porous architecture, uniform thickness, excellent tensile strength, and optical transparency. In vivo wound healing experiments using full-thickness skin wounds in Sprague–Dawley rats demonstrated the patch’s superior performance. Treatment with the sCO₂ ADM patch accelerated wound closure, reduced inflammation, and enhanced granulation tissue formation compared to both untreated controls and two commercially available ADM products. Histological analysis revealed improved re-epithelialization and collagen deposition, while molecular and immunohistochemical assessments showed decreased reactive oxygen species (ROS) and pro-inflammatory cytokines. Simultaneously, the treatment upregulated key proliferation and remodeling markers including alpha smooth muscle actin (α-SMA), vimentin, and transforming growth factor beta 1 (TGF-β1). These findings demonstrate that the SCderm Matrix promotes wound healing through multiple mechanisms: modulating inflammatory responses, enhancing antioxidant defenses, and supporting tissue regeneration. The results suggest this biomaterial has significant potential as an effective and versatile solution for clinical wound care applications. Full article

Background: Co-administration of vaccines can impact the immune response and safety. We aim to systematically review the current scientific literature and find evidence regarding the immunogenicity and safety of pneumococcal vaccines co-administered with common vaccines that are recommended for travelers, including hepatitis A, hepatitis B, yellow fever, tetanus, diphtheria, and acellular pertussis (Tdap), Japanese encephalitis, rabies, typhoid, or meningococcal (MCV) vaccine in adults (18 years or older). Methods: We followed the PRISMA 2020 guidelines and used the PICOS process to select the keywords. We searched PubMed, Web of Science, Scopus, EMBASE, and Google from 1 January 2000 to 30 June 2024. We included randomized controlled trials, non-randomized controlled trials, observational studies, case series, and case reports in adults, all published in English. Results: Out of 598 articles screened, 6 studies were included in our study. Three studies involved immunocompetent individuals, and three involved immunocompromised individuals. Co-administration of pneumococcal vaccine with Tdap or Hepatitis A in immunocompetent individuals was safe and immunogenic. Similar findings were reported for immunocompromised individuals when pneumococcal vaccines were co-administered with Tdap, hepatitis A, and hepatitis B. However, no reports investigated the co-administration of yellow fever, rabies, Japanese encephalitis, and typhoid. Two non-randomized studies in immunocompromised individuals had a high risk of bias. Conclusions: The studies collectively indicate that the co-administration of pneumococcal vaccines with Hepatitis A and Tdap vaccines in adult immunocompetent and immunocompromised individuals is safe and immunogenic. However, a knowledge gap remains, and further high-quality studies are needed, particularly due to the limited number of studies and the potential risk of bias. Full article

Chronic wounds represent a major therapeutic challenge, with limited effective treatment options currently available. Both cellular and acellular approaches are being explored to address this issue, with mesenchymal stromal cells (MSCs) emerging as a promising option. While these cells have been extensively studied, alternative stromal cell sources, such as fibroblasts (Fbs), may also possess comparable therapeutic potential. Thus, this review focuses on stromal cell-derived secretomes (conditioned medium) as a source of acellular therapy for chronic wounds and presents the available wound-healing models (in vitro, ex vivo, and in vivo) suitable for evaluating their therapeutic efficacy, prior to clinical application. By conducting an analysis of the existing studies, we present the impact of the cell culture conditions on the enhancement in the bioactivity of the MSC/Fb-derived conditioned medium, a research area that continues to evolve. Full article

Background/Objectives: Immediate implant-based breast reconstruction is an established option for selected patients undergoing mastectomy. However, patients with large and ptotic breasts present specific reconstructive challenges, often requiring tailored approaches to minimize complications and optimize aesthetics. This pilot study aimed to evaluate the clinical feasibility and effectiveness of a mobile application developed to support intraoperative decision-making based on an institutional algorithm for breast reconstruction. It is also important to underline that this pilot study was exploratory in nature and primarily aimed at assessing feasibility and adherence to an app-based decision pathway, rather than comparative efficacy. Methods: We conducted a prospective observational study from October 2023 to December 2024 at the University Hospital of Sassari. Female patients with large and ptotic breasts undergoing immediate implant-based reconstruction were included. A mobile app, developed using MIT App Inventor 2, implemented our institution’s algorithm and guided surgeons through both preoperative and intraoperative decision-making. Surgical options included subpectoral, prepectoral with autologous fascial flaps, or prepectoral with acellular dermal matrix (ADM) reconstruction, depending on flap thickness and fascia integrity. Results: Sixteen patients (21 reconstructed breasts) were included. Surgical planning and execution followed app-generated recommendations in all cases, with no intraoperative deviations. Subpectoral reconstruction was performed in six patients, prepectoral with ADM in eight, and prepectoral with fascial flaps in two. The app was rated positively by all surgeons and facilitated consistent decision-making. Conclusions: The proposed mobile application, described in this pilot study, proved to be a feasible and effective decision-support tool for implant-based breast reconstruction in patients with challenging anatomy. It standardized surgical choices, supported training, and has the potential to enhance reproducibility and safety in complex reconstructive procedures. Full article

Small vascular graft engineering may help reduce early vein graft failure. We assessed the feasibility, safety, and in vivo vascular regeneration potential of the decellularised human saphenous vein (D-hSV) with and without pre-seeding with porcine endothelial-like cells (ELCs) following grafting in porcine carotid artery (CA). A total of 14 pigs received CA grafting of control D-hSVs (n = 7) or D-hSVs seeded with ELCs (SD-hSV; n = 7). Ultrasound vascular Doppler was undertaken before and after grafting, and at 4 weeks. Outcome measures included patency, intimal thickening (IT), in situ vascular regeneration, endothelial cell (EC) coverage, neo-angiogenesis, mesenchymal–EC transition, and contractile cells. All animals reached the predefined culling point in good health, with no feasibility/safety concerns. Mild graft dilatation occurred at 4 weeks vs. baseline, with no difference between groups. In total, 9/14 grafts (64.3%) remained patent at 4 weeks (4/7 (57.1%) vs. 5/7 (71.4%) in the D-hSV and SD-hSV groups, respectively). IT increased from 17.1 ± 4.7% at baseline to 54.1 ± 12.2% at 4 weeks. Vascular regeneration occurred in all patent grafts with EC coverage, an increase in collagen and elastin, vimentin, SM-MHC-11, and calponin, with no difference between groups. The D-hSV for arterial vascular grafting is feasible and safe and associated with signs of in situ vascular regeneration by host cells at 4 weeks. Pre-seeding with ELCs did not add benefits. Full article

Hypoxic preconditioning (HP) is a promising approach to enhance the therapeutic efficacy of mesenchymal stem cells (MSCs) by modulating their oxidative stress response, metabolic activity, and secretome composition. Conditioned media (CM) obtained from MSCs cultured under hypoxia contains bioactive molecules and extracellular vesicles (EVs) that support regenerative processes. However, the effects of varying oxygen levels on the redox status and physicochemical characteristics of MSC-derived CM remain incompletely understood. This study aimed to investigate how two physiologically relevant oxygen concentrations (1% and 5%) influence oxidative stress parameters and nanoparticle features in Wharton’s jelly-derived MSC (WJ-MSC)-conditioned media. Cells were cultured under 1% or 5% O₂ and subjected to serum starvation for 48 or 72 h. CM samples were analyzed for total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI). Nanoparticle size and zeta potential were evaluated using dynamic light scattering (DLS), and HIF-1α levels were quantified via ELISA. Results showed that CM from 1% O₂ cultures exhibited significantly higher oxidative stress, with elevated TOS and OSI values and reduced TAS levels, particularly after 72 h. Nanoparticle size was initially larger under 1% O₂ but decreased with time, whereas 5% O₂ supported more stable size profiles. Zeta potential measurements revealed more negative values under 5% O₂, indicating greater colloidal stability. HIF-1α expression markedly increased under 1% O₂, confirming hypoxia-induced cellular adaptation. In conclusion, this study demonstrates that graded hypoxia distinctly modulates oxidative stress and nanoparticle characteristics in MSC-derived CM. These findings provide a basis for optimizing hypoxic preconditioning protocols to improve the quality and therapeutic potential of acellular MSC-based therapies. Full article