An injectable and biodegradable hydrogel incorporated with photoregulated NO generators to heal MRSA-infected wounds.

The development of degradable hydrogel fillers with high antibacterial activity and wound-healing property is urgently needed for the treatment of infected wounds. Herein, an injectable, degradable, photoactivated antibacterial hydrogel (MPDA-BNN6@Gel) was developed by incorporating BNN6-loaded mesoporous polydopamine nanoparticles (MPDA-BNN6 NPs) into a fibrin-based hydrogel. After administration, MPDA-BNN6@Gel created local hyperthermia and released large quantities of NO gas to treat methicillin-resistant Staphylococcus aureus infection under the stimulation of an 808 nm laser. Experiments confirmed that the bacteria were eradicated through irreversible damage to the cell membrane, genetic metabolism, and material energy. Furthermore, in the absence of laser irradition, the fibrin and small amount of NO that originated from MPDA-BNN6@Gel promoted wound healing in vivo. This work indicates that MPDA-BNN6@Gel is a promising alternative for the treatment of infected wounds and provides a facile tactic to design a photoregulated bactericidal hydrogel for accelerating infected wound healing. STATEMENT OF SIGNIFICANCE: The development of a degradable hydrogel with high antibacterial activity and wound-healing property is an urgent need for the treatment of infected wounds. Herein, an injectable, degradable, and photo-activated antibacterial hydrogel (MPDA-BNN6@Gel) has been developed by incorporating BNN6-loaded mesoporous polydopamine nanoparticles (MPDA-BNN6 NPs) into a fibrin-based hydrogel. After administration of MPDA-BNN6@Gel, the MPDA-BNN6@Gel could generate local hyperthermia and release large quantities of NO gas to treat the methicillin-resistant Staphylococcus aureus infection under the irradiation of 808 nm laser. Furthermore, in the absence of a laser, the fibrin and a small amount of NO originating from MPDA-BNN6@Gel could promote wound healing in vivo.

Platelet-rich fibrin for root coverage: A plausible approach in periodontal plastic and esthetic surgery.

Predictable esthetic root coverage has evolved into conventional treatment modalities making cosmetic procedures an integral part of periodontal treatment. The advent of second-generation platelet concentrates, i.e., platelet-rich fibrin (PRF), has broad clinical application in medical as well as dental field with its recent use for recession defects. The simplicity of PRF procurement and its low cost makes it most suitable for use in daily clinical practice. This particular case report foregrounds the benefit of PRF membrane along with coronally repositioned flap for mucogingival surgery on the labial surface of an upper anterior tooth.

Résumé La couverture radiculaire esthétique prévisible a évolué vers des modalités de traitement conventionnelles faisant des procédures cosmétiques une partie intégrante du parodontal traitement. L'avènement des concentrés plaquettaires de deuxième génération, c'est-à-dire la fibrine riche en plaquettes (PRF), a une large application clinique en médecine comme ainsi que le domaine dentaire avec son utilisation récente pour les défauts de récession. La simplicité de l'approvisionnement en PRF et son faible coût le rendent particulièrement adapté utilisation dans la pratique clinique quotidienne. Ce rapport de cas particulier met en avant les avantages de la membrane PRF avec le volet repositionné coronairement pour chirurgie mucogingivale sur la surface labiale d'une dent antérieure supérieure.

Differential effects of rat ADSCs encapsulation in fibrin matrix and combination delivery of BDNF and Gold nanoparticles on peripheral nerve regeneration.

BACKGROUND: Fibrin as an extracellular matrix feature like biocompatibility, creates a favorable environment for proliferation and migration of cells and it can act as a reservoir for storage and release of growth factors in tissue engineering. METHODS: In this study, the inner surface of electrospun poly (lactic-co-glycolic acid) (PLGA) nanofibrous conduit was biofunctionalized with laminin containing brain derived neurotrophic factor (BDNF) and gold nanoparticles in chitosan nanoparticle. The rats were randomly divided into five groups, including autograft group as the positive control, PLGA conduit coated by laminin and filled with DMEM/F12, PLGA conduit coated by laminin and filled with rat-adipose derived stem cells (r-ADSCs), PLGA conduit coated by laminin containing gold-chitosan nanoparticles (AuNPs-CNPs), BDNF-chitosan nanoparticles (BDNF-CNPs) and filled with r-ADSCs or filled with r-ADSCs suspended in fibrin matrix, and they were implanted into a 10 mm rat sciatic nerve gap. Eventually, axonal regeneration and functional recovery were assessed after 12 weeks. RESULTS: After 3 months post-surgery period, the results showed that in the PLGA conduit filled with r-ADSCs without fibrin matrix group, positive effects were obtained as compared to other implanted groups by increasing the sciatic functional index significantly (p < 0.05). In addition, the diameter nerve fibers had a significant difference mean in the PLGA conduit coated by laminin and conduit filled with r-ADSCs in fibrin matrix groups relative to the autograft group (p < 0.001). However, G-ratio and amplitude (AMP) results showed that fibrin matrix might have beneficial effects on nerve regeneration but, immunohistochemistry and real-time RT-PCR outcomes indicated that the implanted conduit which filled with r-ADSCs, with or without BDNF-CNPs and AuNPs-CNPs had significantly higher expression of S100 and MBP markers than other conduit implanted groups (p < 0.05). CONCLUSIONS: It seems, in this study differential effects of fibrin matrix, could be interfered it with other factors thereby and further studies are required to determine the distinctive effects of fibrin matrix combination with other exogenous factors in peripheral nerve regeneration.

Novel autologous, high concentrated fibrin as advanced hemostatic agent for coronary surgery.

BACKGROUND: Variability in transfusion outcomes and excessive postoperative bleeding represents a significant problem in cardiac surgery. The effort to reduce bleeding complications and transfusion outcomes is desirable. Our study investigated the feasibility of reducing bleeding complications and transfusion requirements by applying perioperatively prepared autologous bio-regenerative fibrin sealant. METHODS: A prospective, case-control study enrolled 74 patients undergoing coronary artery bypass grafting by a single surgeon. Patients in the control group (N = 43), received traditional methods of hemostasis, while patients in the experimental group (N = 31) were treated additionally with autologous bio-regenerative fibrin. RESULTS: Patients were well-matched with regard to basic demographic, laboratory and procedural data. Allogeneic blood transfusion requirement in control group was 39.5 % (17 of 43 patients), compared to 6.5 % (2 of 31 patients) in treated group (p < 0,001). The lower infection rate in the experimental group was also noted. No safety issues were identified during the preparation and application process. CONCLUSION: Autologous bio-regenerative fibrin can be safely prepared, with no time consuming, and was demonstrated to be a useful tool to decrease allogeneic blood transfusion requirements following elective coronary artery bypass grafting surgery. A prospective randomized trial is needed to confirm these findings.

Effects of BMP-2 compound with fibrin on osteoporotic vertebral fracture healing in rats.

OBJECTIVES: To investigate the effects of bone morphogenetic protein-2 (BMP-2) compound with fibrin on osteoporotic vertebral fracture healing in rats. METHODS: For the present study 160 Specific-Pathogen Free 32-week-old female Sprague-Dawley rats were used. 120 rats were randomly divided in three groups (experimental, model and sham operation group- n=40 per group) and were ovariectomized to establish the osteoporosis model. 40 rats served as a control group without treatment. The expression of BMP-2 in the fracture zone at the 4th, 6th, 8th, and 12th weeks was detected by qRT-PCR. The expression of BALP and CTX-I in serum at the 12th week was detected by Elisa. RESULTS: At week 8, the morphology of the sham operation group was the same and the fracture healing occurred more slowly than in the other groups. At week 12, the expression of BMP-2 in the model group was significantly higher than that in the other three groups (p<0.05). At week 12, the maximum load, maximum strain, and elastic modulus of model group were significantly lower than those of the other three groups. CONCLUSIONS: BMP-2 compound with fibrin can enhance the timing and quality of bone fracture healing in rats.

Enhanced therapeutic index of liposomal doxorubicin Myocet locally delivered by fibrin gels in immunodeficient mice bearing human neuroblastoma.

Caelyx and Myocet are clinically used liposomal forms of doxorubicin (Dox). To explore ways to improve their therapeutic index, we have studied their activity in vitro and in vivo when locally delivered by fibrin gels (FBGs). In vivo local toxic and anti-tumour activities of loaded FBGs were assessed in two immunodeficient mouse orthotopic human neuroblastoma (NB) models after application in the visceral space above the adrenal gland, either still tumour-bearing or after tumour removal. In parallel, in vitro assays were used to mimic the in vivo overlaying of FBGs on the tumour surface. FBGs were prepared with different concentrations of fibrinogen (FG) and clotted in the presence of Ca2+ and thrombin. The in vitro assays showed that FBGs loaded with Myocet possess a cytotoxic activity against NB cell lines generally greater than those loaded with free Dox or Caelyx. In vivo FBGs loaded with Myocet showed lower general and local toxicities as compared to gels loaded with Caelyx or free Dox, and also to free Dox administered i.v. (all treatments with Dox at 2.5 mg/Kg). The anti-tumour activity, evaluated in the two mouse orthotopic NB models of adjuvant and neo-adjuvant therapy, resulted in a better performance of FBGs loaded with Myocet compared to the other local (FBGs loaded with Caelyx or free Dox) or systemic (free Dox) treatments (administered at 2.5 and 5 mg/Kg Dox). Specifically, the application of FBGs at 40 mg/mL in the adjuvant model caused 92 % tumour volume reduction, while by the neo-adjuvant application of FBGs at 22 mg/mL a re-growing tumour volume reduction of 89 % was obtained. Taken together, our in vitro and in vivo results indicate a significantly higher activity for the FBGs loaded with Myocet. In particular, the lower toicity coupled with the higher anti-tumour activity on both the local treatment modalities strongly suggest a better therapeutic index when Myocet is administered through FBGs. Therefore, FBGs loaded with Myocet may be considered as a possible new tool for the loco-regional treatment of NB or even other tumour histotypes treatable by loco-regional chemotherapy.

Barrier agents for adhesion prevention after gynaecological surgery.

BACKGROUND: Pelvic adhesions can form secondary to inflammation, endometriosis, or surgical trauma. Strategies to reduce pelvic adhesion formation include placing barrier agents such as oxidised regenerated cellulose, polytetrafluoroethylene, and fibrin or collagen sheets between pelvic structures. OBJECTIVES: To evaluate the effects of barrier agents used during pelvic surgery on rates of pain, live birth, and postoperative adhesions in women of reproductive age. SEARCH METHODS: We searched the following databases in August 2019: the Cochrane Gynaecology and Fertility (CGF) Specialised Register of Controlled Trials, MEDLINE, Embase, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, the Cochrane Central Register of Controlled Trials (CENTRAL), Epistemonikos, and trial registries. We searched reference lists of relevant papers, conference proceedings, and grey literature sources. We contacted pharmaceutical companies for information and handsearched relevant journals and conference abstracts. SELECTION CRITERIA: Randomised controlled trials (RCTs) on the use of barrier agents compared with other barrier agents, placebo, or no treatment for prevention of adhesions in women undergoing gynaecological surgery. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed trials for eligibility and risk of bias and extracted data. We calculated odds ratios (ORs) or mean differences (MDs) with 95% confidence intervals (CIs) using a fixed-effect model. We assessed the overall quality of the evidence using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) methods. MAIN RESULTS: We included 19 RCTs (1316 women). Seven RCTs randomised women; the remainder randomised pelvic organs. Laparoscopy (eight RCTs) and laparotomy (11 RCTs) were the primary surgical techniques. Indications for surgery included myomectomy (seven RCTs), ovarian surgery (five RCTs), pelvic adhesions (five RCTs), endometriosis (one RCT), and mixed gynaecological surgery (one RCT). The sole indication for surgery in three of the RCTs was infertility. Thirteen RCTs reported commercial funding; the rest did not state their source of funding. No studies reported our primary outcomes of pelvic pain and live birth rate. Oxidised regenerated cellulose versus no treatment at laparoscopy or laparotomy (13 RCTs) At second-look laparoscopy, we are uncertain whether oxidised regenerated cellulose at laparoscopy reduced the incidence of de novo adhesions (OR 0.50, 95% CI 0.30 to 0.83, 3 RCTs, 360 participants; I² = 75%; very low-quality evidence) or of re-formed adhesions (OR 0.17, 95% CI 0.07 to 0.41, 3 RCTs, 100 participants; I² = 36%; very low-quality evidence). At second-look laparoscopy, we are uncertain whether oxidised regenerated cellulose affected the incidence of de novo adhesions after laparotomy (OR 0.72, 95% CI 0.42 to 1.25, 1 RCT, 271 participants; very low-quality evidence). However, the incidence of re-formed adhesions may have been reduced in the intervention group (OR 0.38, 95% CI 0.27 to 0.55, 6 RCTs, 554 participants; I² = 41%; low-quality evidence). No studies reported results on pelvic pain, live birth rate, adhesion score, or clinical pregnancy rate. Expanded polytetrafluoroethylene versus oxidised regenerated cellulose at gynaecological surgery (two RCTs) We are uncertain whether expanded polytetrafluoroethylene reduced the incidence of de novo adhesions at second-look laparoscopy (OR 0.93, 95% CI 0.26 to 3.41, 38 participants; very low-quality evidence). We are also uncertain whether expanded polytetrafluoroethylene resulted in a lower adhesion score (out of 11) (MD -3.79, 95% CI -5.12 to -2.46, 62 participants; very low-quality evidence) or a lower risk of re-formed adhesions (OR 0.13, 95% CI 0.02 to 0.80, 23 participants; very low-quality evidence) when compared with oxidised regenerated cellulose. No studies reported results regarding pelvic pain, live birth rate, or clinical pregnancy rate. Collagen membrane with polyethylene glycol and glycerol versus no treatment at gynaecological surgery (one RCT) Evidence suggests that collagen membrane with polyethylene glycol and glycerol may reduce the incidence of adhesions at second-look laparoscopy (OR 0.04, 95% CI 0.00 to 0.77, 47 participants; low-quality evidence). We are uncertain whether collagen membrane with polyethylene glycol and glycerol improved clinical pregnancy rate (OR 5.69, 95% CI 1.38 to 23.48, 39 participants; very low-quality evidence). One study reported adhesion scores but reported them as median scores rather than mean scores (median score 0.8 in the treatment group vs median score 1.2 in the control group) and therefore could not be included in the meta-analysis. The reported P value was 0.230, and no evidence suggests a difference between treatment and control groups. No studies reported results regarding pelvic pain or live birth rate. In total, 15 of the 19 RCTs included in this review reported adverse events. No events directly attributed to adhesion agents were reported. AUTHORS' CONCLUSIONS: We found no evidence on the effects of barrier agents used during pelvic surgery on pelvic pain or live birth rate in women of reproductive age because no trial reported these outcomes. It is difficult to draw credible conclusions due to lack of evidence and the low quality of included studies. Given this caveat, low-quality evidence suggests that collagen membrane with polyethylene glycol plus glycerol may be more effective than no treatment in reducing the incidence of adhesion formation following pelvic surgery. Low-quality evidence also shows that oxidised regenerated cellulose may reduce the incidence of re-formation of adhesions when compared with no treatment at laparotomy. It is not possible to draw conclusions on the relative effectiveness of these interventions due to lack of evidence. No adverse events directly attributed to the adhesion agents were reported. The quality of the evidence ranged from very low to moderate. Common limitations were imprecision and poor reporting of study methods. Most studies were commercially funded, and publication bias could not be ruled out.

Effect of the CCL5-Releasing Fibrin Gel for Intervertebral Disc Regeneration.

OBJECTIVE: To explore if chemokine (C-C motif) ligand 5 (CCL5) delivery could recruit annulus fibrosus (AF) cells to the injury sites and facilitate the repair of ruptured AF. DESIGN: The effects of CCL5 on bovine AF cells in vitro were tested by transwell assay and quantitative real-time polymerase chain reaction. Fibrin gel containing CCL5 was used to treat annulotomized bovine caudal discs cultured under dynamic loading conditions. After 14 days of loading, the samples were collected for histological examination. A pilot animal study was performed using sheep cervical discs to investigate the effect of fibrin gel encapsulated with CCL5 for the treatment of ruptured AF. After 14 weeks, the animals were sacrificed, and the discs were scanned with magnetic resonance imaging before histopathological examination. RESULTS: CCL5 showed a chemotactic effect on AF cells in a dose-dependent manner. AF cells cultured with CCL5 in vitro did not show any change of the gene expression of CCL5 receptors, catabolic and proinflammatory markers. In vitro release study showed that CCL5 exhibited sustained release from the fibrin gel into the culture media; however, in the organ culture study CCL5 did not stimulate homing of AF cells toward the defect sites. The pilot animal study did not show any repair effect of CCL5. CONCLUSIONS: CCL5 has a chemotactic effect on AF cells in vitro, but no ex vivo or in vivo regenerative effect when delivered within fibrin gel. Further study with a stronger chemotactic agent and/or an alternate biomaterial that is more conductive of cell migration is warranted.

Comparison of outcomes in totally tubeless percutaneous nephrolithotomy according to nephrostomy tract sealing with fibrin versus gelatin matrix: a propensity score matching study.

To investigate and compare surgical outcomes in totally tubeless percutaneous nephrolithotomy (ttPCNL) patients according to the type of sealant during nephrostomy tract closure, the records of 158 patients who underwent ttPCNL were retrospectively reviewed. Fibrin sealant [Tisseel®; n = 107, fibrin-only sealant (FS)] or gelatin matrix hemostatic sealant [FloSeal®; n = 51, gelatin matrix sealant (GS)] was applied during tract closure according to surgeon's preference. On the first postoperative day, computed tomography (CT) was scanned for all patients. Unsatisfactory radiological outcome (URO) was defined as any postoperative hematoma or urinoma (≥ 2 cm) on the CT. Unsatisfactory clinical outcome (UCO) was defined as any adverse event requiring additional intervention. Both UROs and UCOs were sub-classified as either hemorrhage or drainage related. 2:1 propensity score matching was applied according to clinical parameters. Median age was 58 (19-78) years and a mean stone size was 2.1 ± 1.1 cm. The treatment success rate (stone free or < 4 mm residual) among all patients was 91.1% (144/158). UROs and UCOs occurred in 35.4% (86/158) and 11.4% (18/158) of all cases, respectively. Neither of the frequency of URO nor hemorrhage-related UCO was different according to sealant type. However, drainage-related UCOs were more prevalent among the GS group, mainly due to the higher postoperative ureter stenting rate. The postoperative pain severity and the length of hospitalization were comparable between groups. In summary, using GS rather than FS during tract closure did not worsen hemorrhage-related outcomes. However, the clinical risk of ureter occlusion requiring additional temporary ureteral stenting was increased.

Fibrin Clots Maintain the Viability and Proliferative Capacity of Human Mesenchymal Stem Cells: An In Vitro Study.

BACKGROUND: Augmentation of soft-tissue repairs with an autologous fibrin clot has been used clinically for nearly four decades; however, fibrin clots tend to produce an abundance of scar tissue, which is known to inhibit soft-tissue regeneration. Mesenchymal stem cells (MSCs) embedded in fibrin clots before repair could reduce scar tissue deposition and facilitate soft-tissue regeneration. To our knowledge, no published studies have directly evaluated the viability or bioactivity of MSCs in fresh human fibrin clots over time. The purpose of this study was to evaluate the viability and bioactivity of human MSCs inside human fibrin clots over time in nutritive and non-nutritive culture media. QUESTIONS/PURPOSES: We hypothesized that human MSCs would (1) be captured inside fibrin clots and retain their proliferative capacity, (2) remain viable for at least 7 days in the fibrin clots, (3) maintain their proliferative capacity for at least 7 days in the fibrin clots without evidence of active apoptosis, and (4) display similar viability and proliferative capacity when cultured in a non-nutritive medium over the same time periods. METHODS: Twelve patients (mean age 33.7 years; range 4-72 years) who underwent elective knee surgery were approached between February 2016 and October 2017; all patients agreed to participate and were enrolled. MSCs isolated from human skeletal muscle and banked after prior studies were used for this analysis. On the day of surgery and after expansion of the MSC population, 3-mL aliquots of phosphate-buffered saline containing approximately 600,000 labeled with anti-green fluorescent protein (GFP) antibodies were transported to the operating room, mixed in 30 mL of venous blood from each enrolled patient, and stirred at 95 rpm for 10 minutes to create MSC-embedded fibrin clots. The fibrin clots were transported to the laboratory with their residual blood for analysis. Eleven samples were analyzed after exclusion of one sample because of a processing error. MSC capture was qualitatively demonstrated by enzymatically digesting half of each clot specimen, thus releasing GFP-positive MSCs into culture. The released MSCs were allowed to culture for 7 days. Manual counting of GFP-positive MSCs was performed at 2, 3, 4, and 7 days using an inverted microscope at 100 x magnification to document the change in the number of GFP-positive MSCs over time. The intact remaining half of each clot specimen was immediately placed in proliferation media and allowed to culture for 7 days. On Days 1, 2, 3, 4, and 7, a small portion of the clot was excised, flash-frozen, cryosectioned (8-µm thickness), and immunostained with antibodies specific to GFP, Ki67 (indicative of active proliferation), and cleaved caspase-3 ([CC3]; indicative of active apoptosis). Using an inverted microscope, we obtained MSC cell counts manually at time zero and after 1, 2, 3, 4, and 7 days of culture. Intact fresh clot specimens were immediately divided in half; one half was placed in nutritive (proliferation media) and the other was placed in non-nutritive (saline) media for 1, 2, 3, 4, and 7 days. At each timepoint, specimens were processed in an identical manner as described above, and a portion of each clot specimen was excised, immediately flash-frozen with liquid nitrogen, cryosectioned (8-µm thickness), and visualized at 200 x using an inverted microscope. The numbers of stain-positive MSCs per field of view, per culture condition, per timepoint, and per antibody stain type were counted manually for a quantitative analysis. Raw data were statistically compared using t-tests, and time-based correlations were assessed using Pearson's correlation coefficients. Two-tailed p values of less than 0.05 (assuming unequal variance) were considered statistically significant. RESULTS: Green fluorescence, indicative of viable GFP-positive MSCs, was absent in all residual blood samples after 48 hours of culturing; GFP-positive MSCs were visualized after enzymatic digestion of clot matrices. The number of GFP-positive MSCs per field of view increased between the 2-day and 7-day timepoints (mean 5.4 ± 1.5; 95% confidence interval, 4.7-6.1 versus mean 17.0 ± 13.6; 95% CI, 10.4-23.5, respectively; p = 0.029). Viable GFP-positive MSCs were present in each clot cryosection at each timepoint up to 7 days of culturing (mean 6.2 ± 4.3; 95% CI, 5.8-6.6). There were no differences in MSC counts between any of the timepoints. There was no visible evidence of GFP +/CC3 + double-positive MSCs. Combining all timepoints, there were 0.34 ± 0.70 (95% CI, 0.25-0.43) GFP+/Ki67+ double-positive MSCs per field of view. The mitotic indices at time zero and Day 7 were 7.5% ± 13.4% (95% CI, 3.0%-12.0%) and 7.2% ± 14.3% (95% CI, 3.3%-12,1%), respectively (p = 0.923). There was no visible evidence of GFP +/CC3 + double-positive MSCs (active apoptosis) at any timepoint. For active proliferation in saline-cultured fibrin clots, we found averages of 0.1 ± 0.3 (95% CI, 0.0-0.2) and 0.4 ± 0.9 (95% CI, 0.0-0.8) GFP/Ki67 double-positive MSCs at time zero and Day 7, respectively (p = 0.499). The mitotic indices in saline culture at time zero and Day 7 were 2.9% ± 8.4% (95% CI, 0.0%-5.8%) and 9.1% ± 20.7% (95% CI, 1.2%-17.0%; p = 0.144). There was no visible evidence of GFP +/CC3 + double-positive MSCs (active apoptosis) at any timepoint in either culturing condition. CONCLUSION: These preliminary in vitro results show that human MSCs mixed in unclotted fresh human venous blood were nearly completely captured in fibrin clots and that seeded MSCs were capable of maintaining their viability, proliferation capacity, and osteogenic differentiation capacity in the fibrin clot for up to 7 days, independent of external sources of nutrition. CLINICAL RELEVANCE: Fresh human fibrin clots have been used clinically for more than 30 years to improve soft-tissue healing, albeit with scar tissue. Our results demonstrate that allogenic human MSCs, which reduce soft-tissue scarring, can be captured and remain active inside human fibrin clots, even in the absence a nutritive culture medium.

Engineered skin graft with stromal vascular fraction cells encapsulated in fibrin-collagen hydrogel: A clinical study for diabetic wound healing.

Despite the abundance of skin substitutes in the worldwide market, major hurdles in developing more complex tissues include the addition of skin appendages and vascular networks as the most important structure. The aim of this research was a clinical feasibility study of a novel prevascularized skin grafts containing the dermal and epidermal layer using the adipose stromal vascular fraction (SVF)-derived endothelial cell population for vascular network regeneration. Herein, we characterized hydrogel with emphasis on biological compatibility and cell proliferation, migration, and vitality. The therapeutic potential of the prevascularized hydrogel transplanted on five human subjects as an intervention group with diabetic wounds was compared with nonvascularized skin grafts as the control on five patients. Wound planimetric and biometric analysis was performed using a Mann-Whitney nonparametric t-test (p ≤ .05). The fibrin-collagen hydrogel was suitable for skin organotypic cell culture. There was a significant (p ≤ .05) increased in skin thickness and density in the vascular beds of the hypodermis measured with skin scanner compared with that in the control group. No significant macroscopic differences were observed between the intervention and control groups (p ≤ .05). In summary, we report for the first time the use of autologous dermal-epidermal skin grafts with intrinsic vascular plexus in a clinical feasibility study. The preliminary data showed that SVF-based full-thickness skin grafts are safe and accelerate the wound healing process. The next stage of the study is a full-scale randomized clinical trial for the treatment of patients with chronic wounds.

Fibrin gels entrapment of a doxorubicin-containing targeted polycyclodextrin: Evaluation of in vivo antitumor activity in orthotopic models of human neuroblastoma.

In vivo local antitumor activity of fibrin gels (FBGs) loaded with the poly-cyclodextrin oCD-NH2/Dox, compared to free Dox, was evaluated in two mouse orthotopic neuroblastoma (NB) models, after positioning of the releasing devices in the visceral space. FBGs were prepared at the fibrinogen (FG) concentrations of 22 and 40 mg/ml clotted in the presence of 0.81 mM/mg FG Ca2+ and 1.32 U/mg FG thrombin. Our results indicate that FBGs loaded with oCD-NH2/Dox and applied as neoadjuvant loco-regional treatment, show an antitumor activity significantly greater than that displayed by the same FBGs loaded with identical dose of Dox or after free Dox administered intra venous (iv). In particular, FBGs prepared at 40 mg/ml showed a slightly lower antitumor activity, although after their positioning we observed a significant initial reduction of tumor burden lasting for several days after gel implantation. FBGs at 22 mg/ml loaded with oCD-NH2/Dox and applied after tumor removal (adjuvant treatment model) showed a significantly better antitumor activity than the iv administration of free Dox, with 90% tumor regrowth reduction compared to untreated controls. In all cases the weight loss post-treatment was limited after gel application, although in the adjuvant treatment the loss of body weight lasted longer than in the other treatment modality. In accordance with our recent published data on the low local toxic effects of FBGs, the present findings also underline an increase of the therapeutic index of Dox when locally administered through FBGs loaded with the oCD-NH2/Dox complex.

Uso de plasma rico en fibrina comparado con colágeno en el tratamiento de recesión gingival utilizando la técnica estenopéica. Ensayo clínico aleatorizado / Use of fibrin-rich plasma compared to collagen in the treatment of gingival recession using the stenopic technique. Randomized clinical trial

La recesión gingival (RG) es un problema de salud bucodental frecuente que aumenta con la edad, predispone a hipersensibilidad dentaria, caries radicular, inflamación gingival y efectos antiestéticos. El objetivo de este ensayo clínico aleatorizado fue evaluar comparativamente el efecto clínico del recubrimiento radicular utilizando la técnica estenopéica Pinhole con colágeno y la técnica estenopéica Pinhole modificada al incorporarle plasma rico en fibrina (PRF). Veintiséis participantes sistémicamente sanos, con diagnóstico de RG grado I de Miller, fueron reclutados y seguidos por 6 meses después de la cirugía. Los parámetros clínicos registrados fueron nivel de inserción clínica (NIC), RG y banda de encía queratinizada. Los participantes fueron asignados aleatoriamente a un grupo en quienes se utilizó PRF con 14 participantes, tratando 36 piezas dentales, y otro grupo en quienes se utilizó membrana de colágeno con 12 participantes, tratando 35 piezas dentales. Los resultados muestran un logro de ganancia en el NIC en ambos grupos, (M = 45.24 %, DE = 17.37 %) en el grupo PRF y (M = 47.37 %, DE = 15.67 %) en el grupo colágeno, diferencia que no fue significativa (p = .59). En ambos grupos existió un aumento significativo en la banda de encía queratinizada (p < .01). El uso de PRF como material de relleno al realizar la técnica estenopéica genera resultados similares al ser comparado con la técnica convencional que utiliza colágeno. Al presentar un menor costo el PRF aumenta las posibilidades que más personas tengan acceso al tratamiento.

Gingival recession (GR) is a frequent oral health disease that increases with age and may increase risk of dental hypersensitivity, root decay, gingival inflammation and aesthetic problems. The aim of this randomized clinical trial was to compare clinical parameters of dental root coverage using Pinhole technique with collagen and modi¬fied Pinhole technique using platelet-rich fibrin (PRF). Twenty-six participants, systemically healthy, with Miller class I GR diagnosis, were recruited and measured at baseline and after 6 months follow-up. Clinical parameters measured included clinical attachment level (ICL), GR and keratinized gingival width (KGW). All participants were randomly assigned to a group using PRF, with 14 participants and 36 teeth treated, and other group using collagen, with 12 participants and 35 teeth treated. Both PRF group and collagen group gained ICL, (M = 45.24 %, SD = 17.37 %) in PRF group and (M = 47.37 %, SD = 15.67 %) in collagen group, with no statistically significant difference (p = .59). Both groups gained KGW (p < .01). Use of PRF as filled material by using Pinhole technique resulted in similar clinical improvements compare to collagen as filled material. Considering that PRF is cheaper than collagen, it increases chances that people can have access to treatment.

Synergistic Application of Platelet-Rich Fibrin and 1% Alendronate in Periodontal Bone Regeneration: A Meta-Analysis.

Periodontal bone regeneration relies on coupled and cooperative bone formation and resorption. Accordingly a novel strategy on concurrent use of platelet-rich fibrin (PRF) (anabolic agent) and 1% alendronate (ALN) (anticatabolic agent) was proposed recently in regenerative periodontal treatment. It was supposed to enhance bone formation and reduce bone resorption simultaneously. However, there is a lack of evidence-based studies to answer whether this concurrent application was superior to single application until now. Besides, concerns on ALN lead to some reservation on this synergistic way. ALN may impair new bone formation and necrotize jaws. Thus, in order to compare the clinical efficacy between PRF plus 1%ALN and PRF alone on periodontal bone regeneration, we performed present systematic review and meta-analysis. Because it is the prerequisite for measuring the combined efficacy of PRF plus 1%ALN, firstly we evaluated the effectiveness of 1%ALN. Our data indicated that adjunctive 1%ALN was effective in promoting periodontal bone repair. Further, PRF plus 1%ALN showed a greater capacity for periodontal regeneration than PRF alone with statistical significance. The findings of this study revealed the promising prospects on synergistic application of bone anabolic agents (PRF) and antiresorption medications (1%ALN) in regenerative periodontal treatment.

Current Methods of Maxillofacial Tissue Engineering.

For several decades, the multidisciplinary field of tissue engineering has striven to improve conventional methods of dental, oral, and craniofacial rehabilitation for millions of people annually. Several bone tissue engineering strategies are now readily available in the clinic. Enrichment of autologous products, growth factors, and combination approaches are discussed as ways to enhance the surgeon's traditional armamentarium. Lastly, cutting-edge research such as customized 3-dimensional printed bone scaffolds, tissue engineering strategies for volumetric muscle loss, and temporomandibular joint disc and condyle engineering are briefly discussed as future applications.

Fibrin-hyaluronic acid hydrogel-based delivery of antisense oligonucleotides for ADAMTS5 inhibition in co-delivered and resident joint cells in osteoarthritis.

To date no disease-modifying drugs for osteoarthritis (OA) are available, with treatment limited to the use of pain killers and prosthetic replacement. The ADAMTS (A Disintegrin and Metallo Proteinase with Thrombospondin Motifs) enzyme family is thought to be instrumental in the loss of proteoglycans during cartilage degeneration in OA, and their inhibition was shown to reverse osteoarthritic cartilage degeneration. Locked Nucleic Acid (LNA)-modified antisense oligonucleotides (gapmers) released from biomaterial scaffolds for specific and prolonged ADAMTS inhibition in co-delivered and resident chondrocytes, is an attractive therapeutic strategy. Here, a gapmer sequence identified from a gapmer screen showed 90% ADAMTS5 silencing in a monolayer culture of human OA chondrocytes. Incorporation of the gapmer in a fibrin-hyaluronic acid hydrogel exhibited a sustained release profile up to 14 days. Gapmers loaded in hydrogels were able to transfect both co-embedded chondrocytes and chondrocytes in a neighboring gapmer-free hydrogel, as demonstrated by flow cytometry and confocal microscopy. Efficient knockdown of ADAMTS5 was shown up to 14 days in both cell populations, i.e. the gapmer-loaded and gapmer-free hydrogel. This work demonstrates the use applicability of a hydrogel as a platform for combined local delivery of chondrocytes and an ADAMTS-targeting gapmer for catabolic gene modulation in OA.

Rivaroxaban Promotes Reduction of Embolus Size within Cerebrocortical Microvessels in a Mouse Model of Embolic Stroke.

Previous reports have suggested that direct oral anticoagulants exert a prothrombolytic effect against intracardiac thrombi. We hypothesized that these anticoagulants may also help recanalize occluded intracranial arteries via prothrombolytic effects. In this study, we evaluated the effects of rivaroxaban, a direct oral anticoagulant, on fibrin emboli within the cerebrocortical microvessels in a mouse model of embolic stroke. Fibrin emboli prepared ex vivo were injected into the common carotid artery of male C57BL/6 mice, and embolization in the microvessels on the brain surface was observed through a cranial window. Oral administration of rivaroxaban was initiated a week before injection of the emboli. The number and sizes of the emboli were measured at two time points: immediately after and 3 h after the embolus injection in the rivaroxaban-treated mice (n =6) and untreated mice (n =7). The rates of recanalization and change in the embolus size were analyzed between the two groups. Complete recanalization was observed only in the rivaroxaban group (three mice in the rivaroxaban group compared with none in the control group). A significantly higher rate of reduction of the embolus size was observed in the rivaroxaban group than in the control group (P=0.0216). No significant differences between the two groups were observed in the serum levels of the following coagulation markers: thrombin-antithrombin III complexes, D-dimers, or plasmin-α2-plasmin inhibitor complex. Our findings indicate that rivaroxaban may promote reduction in the size of stagnated fibrin emboli in cerebrocortical microvessels in cases of embolic stroke.

Enhanced uptake and improved anti-tumor efficacy of doxorubicin loaded fibrin gel with liposomal apatinib in colorectal cancer.

Colorectal cancer (CRC) exhibited high incidence rate worldwide and the advanced CRC had a poor prognosis. Thereupon, seeking efficient treatment for CRC is critical. Apatinib is a novel vascular epithelial growth factor receptor (VEGFR) inhibitor with inspiring therapeutic effect in some malignant cancers. In our study, doxorubicin was mixed in fibrin gel and apatinib was encapsulated with self-synthesized liposome. The results showed liposomal apatinib (Lipo-Apatinib) could enhance the intracellular uptake of doxorubicin in vitro. Moreover, compared with doxorubicin loaded fibrin gel (DOX-FG) alone, the combination of DOX-FG and Lipo-Apatinib significantly improved the anti-tumor effect in mice CRC subcutaneous model and abdominal metastasis model Drug combination successfully inhibited tumor angiogenesis and tumor proliferation, and also promoted tumor apoptosis. Our data suggested that combined therapy of DOX-FG and Lipo-Apatinib would be a promising treatment approach for CRC.

Characterization of drug release from fibrin gels loaded with different pharmaceutical and experimental doxorubicin formulations.

BACKGROUND: Local delivery of anticancer drugs represents a desirable type of treatment. Nevertheless, characteristics such as availability, biocompatibility, ease of operation, and efficacy sometimes represent difficult to overcome hurdles. Fibrin gels (FBGs) may be attractive biomaterials for local treatment when loaded with different chemotherapeutics or with polymer-anticancer-drug conjugates and nanoparticles. These components, linked together, might represent candidates to counteract local recurrences or reduce the volume of inoperable tumors. In the present study we analyzed the features of in vitro release of different formulations of doxorubicin (DOXO) from FBGs, and in vivo FBGs degradation. METHODS: In vitro DOXO release from FBGs was studied as a function of thrombin and Ca2+ ion concentrations. DOXO was loaded in FBGs either alone or pre-incorporated in nanoparticles characterized by different physical features. The FBGs in vivo degradation was analyzed after sc or ip positioning. RESULTS: Our results suggest that each of the factors involved in the FBGs preparation may have different effects on drug release. In particular, the fibrinogen (FG) concentration and, above all, the DOXO formulation were found to have the greatest impact. Not surprisingly, we have also found a longer permanence in vivo of FBGs prepared at the highest thrombin, Ca2+ ion, and FG concentrations. CONCLUSIONS: The aim of this work was to study the effect of several conditions for preparing drug delivery systems based on FBGs loaded with different clinical or experimental formulations of DOXO. Our data identify some of these modalities that will be tested in vivo to evaluate their antitumor activity.

PRP as an Adjunct to Rotator Cuff Tendon Repair.

Arthroscopic rotator cuff repair is a commonly performed repair. Technical developments provide surgeons the tools to create biomechanically robust repairs. How can the biological response mirror the strong and stable surgery? Platelet-rich plasma (PRP) is a supraphysiological platelet concentration which may positively augment rotator cuff healing. Not all PRPs are the same. High leukocyte levels and thrombin activation may be detrimental to tendon healing. Thrombin activation triggers an immediate release of growth factors and may actually inhibit some parts of the healing response. Clear differences exist between liquid PRP (products released within hours after activation) and solid fibrin PRP which slowly releases factors over days. The heterogenicity data and grouping liquid and solid PRP together make systematic reviews confusing. Solid PRP fibrin constructs are often associated with increased tendon healing. PRP fibrin matrix offers the greatest promise for improving clinical success after rotator cuff tendon repair.