Embosphere microspheres size for bronchial artery embolization in patients with hemoptysis caused by bronchiectasis: a retrospective comparative analysis of 500-750 versus 700-900 µm microspheres.

BACKGROUND: Bronchial arterial embolization (BAE) has been accepted as an effective treatment for bronchiectasis-related hemoptysis. However, rare clinical trials compare different sizes of specific embolic agents. This study aims to evaluate whether different Embosphere microsphere sizes change the outcome of BAE. METHODS: A retrospective review was conducted on consecutive patients with bronchiectatic hemoptysis who were scheduled to undergo BAE treatment during a period from January 2018 to December 2022. The patients received BAE using microspheres of different sizes: group A patients were treated with 500-750 µm microspheres, and group B patients were treated with 700-900 µm microspheres. The cost of embolic microspheres (Chinese Yuan, CNY), duration of hospitalization, complications, and hemoptysis-free survival were compared between patients in group A and those in group B. A Cox proportional hazards regression model was used to identify predictors of recurrent hemoptysis. RESULTS: Median follow-up was 30.2 months (range, 20.3-56.5 months). The final analysis included a total of 112 patients (49-77 years of age; 45 men). The patients were divided into two groups: group A (N = 68), which received 500-750 µm Embosphere microspheres, and group B (N = 44), which received 700-900 µm Embosphere microspheres. Except for the cost of embolic microspheres(group A,5314.8 + 1301.5 CNY; group B, 3644.5 + 1192.3 CNY; p = 0.042), there were no statistically significant differences in duration of hospitalization (group A,7.2 + 1.4 days; group B, 8 + 2.4days; p = 0.550), hemoptysis-free survival (group A, 1-year, 2-year, 3-year, 85.9%, 75.8%, 62.9%; group B, 1-year, 2-year, 3-year, 88.4%, 81.2%,59.4%;P = 0.060), and complications(group A,26.5%; group B, 38.6%; p = 0.175) between the two groups. No major complications were observed. The multivariate analysis results revealed that the presence of cystic bronchiectasis (OR 1.61, 95% CI 1.12-2.83; P = 0.001) and systemic arterial-pulmonary shunts (SPSs) (OR 1.52, 95% CI 1.10-2.72; P = 0.028) were independent risk factors for recurrent bleeding. CONCLUSIONS: For the treatment of BAE in patients with bronchiectasis-related hemoptysis, 500-750 µm diameter Embosphere microspheres have a similar efficacy and safety profile compared to 700-900 µm diameter Embosphere microspheres, especially for those without SPSs or cystic bronchiectasis. Furthermore, the utilization of large-sized (700-900 µm) Embosphere microspheres is associated with the reduced cost of an embolic agent.

Clinical Safety and Performance of GATT-Patch for Hemostasis in Minimal to Moderate Bleeding During Open Liver Surgery.

INTRODUCTION: Intraoperative blood loss and postoperative hemorrhage affect outcomes after liver resection. GATT-Patch is a new flexible, pliable hemostatic sealant patch comprising fibrous gelatin carrier impregnated with N-hydroxy-succinimide polyoxazoline. We evaluated safety and performance of the GATT-Patch for hemostasis at the liver resection plane. METHODS: Adult patients undergoing elective open liver surgery were recruited in three centers. GATT-Patch was used for minimal to moderate bleeding at the liver resection plane. The primary endpoint was hemostasis of the first-treated bleeding site at 3 min versus a prespecified performance goal of 65.4%. RESULTS: Two trial stages were performed: I (n = 8) for initial safety and II (n = 39) as the primary outcome cohort. GATT-Patch was applied in 47 patients on 63 bleeding sites. Median age was 60.0 (range 25-80) years and 70% were male. Most (66%) surgeries were for colorectal cancer metastases. The primary endpoint was met in 38 out of 39 patients (97.4%; 95% confidence interval: 84.6%-99.9%) versus 65.4% (P < 0.001). Of all the 63 bleeding sites, hemostasis was 82.7% at 30, 93.7% at 60, and 96.8% at 180 s. No reoperations for rebleeding or device-related issues occurred. CONCLUSIONS: When compared to a performance goal derived from state-of-the-art hemostatic agents, GATT-Patch for the treatment of minimal to moderate bleeding during liver surgery successfully and quickly achieved hemostasis with acceptable safety outcomes. (ClinicalTrials.gov Identifier: NCT04819945).

A thermally reversible injectable adhesive for intestinal tissue repair and anti-postoperative adhesion.

Intestine damage is an acute abdominal disease that usually requires emergency sealing. However, traditional surgical suture not only causes secondary damage to the injured tissue, but also results in adhesion with other tissues in the abdominal cavity. To this end, a thermally reversible injectable gelatin-based hydrogel adhesive (GTPC) is constructed by introducing transglutaminase (TGase) and proanthocyanidins (PCs) into a gelatin system. By reducing the catalytic activity of TGase, the density of covalent and hydrogen bond crosslinking in the hydrogel can be regulated to tune the sol-gel transition temperature of gelatin-based hydrogels above the physiological temperature (42 °C) without introducing any synthetic small molecules. The GTPC hydrogel exhibits good tissue adhesion, antioxidant, and antibacterial properties, which can effectively seal damaged intestinal tissues and regulate the microenvironment of the damaged site, promoting tissue repair and regeneration. Intriguingly, temperature-induced hydrogen bond disruption and reformation confer the hydrogel with asymmetric adhesion properties, preventing tissue adhesion when applied in vivo. Animal experiment outcomes reveal that the GTPC hydrogel can seal the damaged intestinal tissue firmly, accelerate tissue healing, and efficiently prevent postoperative adhesion.

Clinical Study on the Treatment of Benign Prostatic Hyperplasia by Embolization of Prostate Artery Based on Embosphere Microspheres and Gelatin Sponge Granules.

Prostatic hyperplasia can cause dysuria, such as frequent urination, urgency of urination, increased nocturia, poor urination, and other symptoms, which seriously affect the quality of life of old men. We aim to compare and analyze the safety and clinical effect of embolization of the target blood vessels of ruptured prostatic hyperplasia with gelatin sponge particles and embosphere microspheres. Methods. The transcatheter MRI was performed in 422 patients. Among them, 198 patients were treated with gelfoam particles and 224 patients were treated with embosphere microspheres. The clinical effect and adverse reactions were observed and analyzed by biochemical and imaging examination. Four hundred and twenty two cases were hemostasis. In the gelatin sponge group, 34 patients had recurrent bleeding 24-36 hours after embolization, 122 patients had different degrees of elevation of prostatic hyperplasia transaminase (31 cases increased to more than 1000 U/L), 198 patients had different degrees of elevation of bilirubin; in the microsphere group, there was no significant difference in prostatic hyperplasia function indexes between the two groups. Conclusion. Compared with the gelfoam embolic agent, the embosphere embolic microsphere has a good efficacy and safety in the treatment of prostatic hyperplasia rupture and hemorrhage, with a light adverse reaction, a low probability of recanalization, and little damage to the postoperative prostatic hyperplasia function, which is conducive to the benign recovery of perioperative patients and is worthy of clinical application.

A Transarterial Chemoembolization of Balloon-Occluded Alternate Infusions of Cisplatin and Gelatin Particles for Hepatocellular Carcinoma: A Phase I/II Multicenter Prospective Study of Safety and Efficacy.

PURPOSE: To evaluate the safety and efficacy of a newly developed technique of balloon-occluded alternate infusions of cisplatin and gelatin particles in transarterial chemoembolization in hepatocellular carcinoma (HCC) and to evaluate the liver damage following the procedure. MATERIALS AND METHODS: Forty-three patients with HCC from 4 medical centers were enrolled in this multicenter prospective study. Of these, 41 patients were observed for 6 months following balloon-occluded alternate infusion transarterial chemoembolization. The primary endpoint was the safety of the procedure, and the secondary endpoint was the objective response rate (ORR) of the HCCs at 2 months following treatment. RESULTS: Three patients experienced adverse events, including 1 patient with facial swelling and skin rash, dissection of the celiac artery, and bland portal vein thrombus. No major adverse events were identified. Two (5.3%) patients regressed from a Child-Pugh classification of A to B. The balloon-occluded alternate infusion transarterial chemoembolization treatment achieved a 22.0% complete response (CR) rate and a 73.2% ORR (95% confidence interval [CI], 57.9%-84.4%). In a retrospective analysis of 23 patients with HCCs above the up-to-7 criteria, the CR rate and ORR of the balloon-occluded alternate infusion transarterial chemoembolization were 21.7% and 82.6% (95% CI, 62.3%-93.6%), respectively. CONCLUSIONS: Balloon-occluded alternate infusion transarterial chemoembolization is safe and effective for achieving a high ORR while preserving liver function.

Effect of a 3% gelatin solution on urinary KIM-1 levels in patients after thyroidectomy: a preliminary randomized controlled trial.

Optimal fluid therapy significantly affects the maintenance of proper tissue perfusion and, consequently, kidney function. An adverse effect of colloids on kidney function is related to the incidence of postoperative kidney failure. The study aimed to assess the effect of a 3% gelatin solution on kidney function based on the urinary kidney injury molecule-1 (uKIM-1) level. This study used a parallel design and enrolled 64 adult patients with a mean age of 52.5 ± 13.1 years, all of whom underwent a thyroidectomy procedure under general anesthesia. Patients were randomly assigned to three comparison groups, each receiving a different dose of 3% gelatin solution during the thyroidectomy procedure. The patients from study groups A (n = 21) and B (n = 21) received a 3% gelatin solution at a dose of 30 ml/kg and 15 ml/kg body weight, respectively, during the first hour of the procedure. The patients from the control group C (n = 22) received an isotonic multi-electrolyte solution. Serum creatinine levels were determined, and urine samples were collected to determine levels of uKIM-1 before, 2 h, and 24 h after surgery. The patients' demographic data, type and volume of fluid and hemodynamic status during the surgery were collected from relevant anesthesia protocols and were included in the study data. There were no statistically significant changes between groups in hemodynamic parameters such as systolic and diastolic blood pressure, heart rate, and oxygen saturation values. A statistically significant increase in uKIM-1 level was noted in patients receiving the 3% gelatin solution regardless of the dose. A statistically significant difference in uKIM-1 level was observed between groups A, B, and C measured 24 h after surgery, with the highest uKIM-1 level in group A. Measurement of uKIM-1 level could be an early and sensitive biomarker of kidney injury. Kidney toxicity of a 3% gelatin solution, evaluated based on the level of uKIM-1 in urine, correlates with transfused fluid volume. This study was retrospectively registered in the ISRCTN clinical trials registry (ISRCTN73266049, 08/04/2021: https://www.isrctn.com/ISRCTN73266049 ).

A Novel Alaska Pollock Gelatin Sealant Shows Higher Bonding Strength and Nerve Regeneration Comparable to That of Fibrin Sealant in a Cadaveric Model and a Rat Model.

BACKGROUND: A novel biocompatible sealant composed of Alaska pollock-derived gelatin (ApGltn) has recently shown good burst strength and biocompatibility in a porcine aorta. The purpose of this study was to investigate the bonding strength and biocompatibility of the ApGltn sealant in transected digital nerves of fresh frozen cadavers and in the sciatic nerves of a rat model. METHODS: Eighty human digital nerves of fresh frozen cadavers were transected for biomechanical traction testing. They were treated with four surgical interventions: (1) suture plus ApGltn sealant; (2) suture; (3) ApGltn sealant; and (4) fibrin sealant. Forty-three sciatic nerves of male Wistar rats were used for functional and histopathologic evaluation. They were treated with six surgical interventions: (1) suture plus ApGltn sealant; (2) suture; (3) ApGltn sealant; (4) fibrin sealant; (5) resection with a 5-mm gap (10 rats per group); and (6) sham operation (three rats). Macroscopic confirmation, muscle weight measurement, and histopathologic findings including G-ratio were examined 8 weeks after the procedure. RESULTS: The maximum failure load of the ApGltn sealant was significantly higher than that of a fibrin sealant (0.22 ± 0.05 N versus 0.06 ± 0.04 N). The maximum failure load of the ApGltn sealant was significantly lower that of suture plus ApGltn sealant (1.37 N) and suture (1.27 N). Functional evaluation and histologic examination showed that sciatic nerves repaired with ApGltn sealant showed similar nerve recovery compared to repair with the suture and fibrin sealant. CONCLUSION: The ApGltn sealant showed higher bonding strength and equal effect of nerve regeneration when compared with the fibrin sealant.

Hemostatic efficacy of two topical adjunctive hemostats in a porcine spleen biopsy punch model of moderate bleeding.

Topical hemostatic agents have become essential tools to aid in preventing excessive bleeding in surgical or emergency settings and to mitigate the associated risks of serious complications. In the present study, we compared the hemostatic efficacy of SURGIFLO® Hemostatic Matrix Kit with Thrombin (Surgiflo-flowable gelatin matrix plus human thrombin) to HEMOBLAST™ Bellows Hemostatic Agent (Hemoblast-a combination product consisting of collagen, chondroitin sulfate, and human thrombin). Surgiflo and Hemoblast were randomly tested in experimentally induced bleeding lesions on the spleens of four pigs. Primary endpoints included hemostatic efficacy measured by absolute time to hemostasis (TTH) within 5 min. Secondary endpoints included the number of product applications and the percent of product needed from each device to achieve hemostasis. Surgiflo demonstrated significantly higher hemostatic efficacy and lower TTH (p < 0.01) than Hemoblast. Surgiflo-treated lesion sites achieved hemostasis in 77.4% of cases following a single product application vs. 3.3% of Hemoblast-treated sites. On average, Surgiflo-treated sites required 63% less product applications than Hemoblast-treated sites (1.26 ± 0.0.51 vs. 3.37 ± 1.16). Surgiflo provided more effective and faster hemostasis than Hemoblast. Since both products contain thrombin to activate endogenous fibrinogen and accelerate clot formation, the superior hemostatic efficacy of Surgiflo in the porcine spleen punch biopsy model seems to be due to Surgiflo's property as a malleable barrier able to adjust to defect topography and to provide an environment for platelets to adhere and aggregate. Surgiflo combines a flowable gelatin matrix and a delivery system well-suited for precise application to bleeding sites where other methods of hemostasis may be impractical or ineffective.

Microvascular decompression for hemifacial spasm involving the vertebral artery: A modified effective technique using a gelatin sponge with a FuAiLe medical adhesive.

Microvascular Decompression for Hemifacial Spasm Involving the Vertebral Artery (VA): A Modified Effective Technique Using a Gelatin Sponge with a FuAiLe Medical Adhesive. (a)The VA pushes the anterior inferior cerebellar artery (AICA) which compressed the root exit zone (REZ) of the facial nerve. (b) The VA was adhered to the petrous dura, and the AICA was decompressed from the REZ by a Teflon pad.

Development of nitric oxide releasing visible light crosslinked gelatin methacrylate hydrogel for rapid closure of diabetic wounds.

Management of non-healing and slow to heal diabetic wounds is a major concern in healthcare across the world. Numerous techniques have been investigated to solve the issue of delayed wound healing, though, mostly unable to promote complete healing of diabetic wounds due to the lack of proper cell proliferation, poor cell-cell communication, and higher chances of wound infections. These challenges can be minimized by using hydrogel based wound healing patches loaded with bioactive agents. Gelatin methacrylate (GelMA) has been proven to be a highly cell friendly, cell adhesive, and inexpensive biopolymer for various tissue engineering and wound healing applications. In this study, S-Nitroso-N-acetylpenicillamine (SNAP), a nitric oxide (NO) donor, was incorporated in a highly porous GelMA hydrogel patch to improve cell proliferation, facilitate rapid cell migration, and enhance diabetic wound healing. We adopted a visible light crosslinking method to fabricate this highly porous biodegradable but relatively stable patch. Developed patches were characterized for morphology, NO release, cell proliferation and migration, and diabetic wound healing in a rat model. The obtained results indicate that SNAP loaded visible light crosslinked GelMA hydrogel patches can be highly effective in promoting diabetic wound healing.

Biosensitive and antibacterial coatings on metallic material for medical applications.

Metallic materials are commonly used for load-bearing implants and as internal fixation devices. It is customary to use austenitic stainless steel, especially surgical grade type 316L SS as temporary and Ti alloys as permanent implants. However, long-term, poor bonding with bone, corrosion, and release of metal ions, such as chromium and nickel occur. These ions are powerful allergens and carcinogens and their uncontrolled leaching may be avoided by surface coatings. Therefore, bioactive glasses (BGs) became a vital biomedical material, which can form a biologically active phase of hydroxycarbonate apatite on their surface when in contact with physiological fluids. To reduce the high coefficient of friction and the brittle nature of BGs, polymers are normally incorporated to avoid the high-temperature sintering/densification of ceramic-only coatings. For medical application, electrophoretic deposition (EPD) is now used for polymer (organic) and ceramic (inorganic) components at room temperature due to its simplicity, control of coating thickness and uniformity, low cost of equipment, ability to coat substrates of intricate shape and to supply thick films in composite form, high purity of deposits as well as no phase transformation during coating. Although extensive research has been conducted on polymer/inorganic composite coatings, only some studies have reported multifunctional properties, such as biological antibacterial activity, enhanced cell adhesion, controlled drug release ability, and mechanical properties. This review will focus on biodegradable coatings, including zien, chitosan, gelatin, cellulose loaded with antibacterial drugs/metallic ions/natural herbs on biostable substrates (PEEK/PMMA/PCL/PLLA layers), which have the potential of multifunctional coating for metallic implants.

Injectable conductive hydrogel can reduce pacing threshold and enhance efficacy of cardiac pacemaker.

Background: Pacemaker implantation is currently used in patients with symptomatic bradycardia. Since a pacemaker is a lifetime therapeutic device, its energy consumption contributes to battery exhaustion, along with its voltage stimulation resulting in local fibrosis and greater resistance, which are all detrimental to patients. The possible resolution for those clinical issues is an injection of a conductive hydrogel, poly-3-amino-4-methoxybenzoic acid-gelatin (PAMB-G), to reduce the myocardial threshold voltage for pacemaker stimulation. Methods: PAMB-G is synthesized by covalently linking PAMB to gelatin, and its conductivity is measured using two-point resistivity. Rat hearts are injected with gelatin or PAMB-G, and pacing threshold is evaluated using electrocardiogram and cardiac optical mapping. Results: PAMB-G conductivity is 13 times greater than in gelatin. The ex vivo model shows that PAMB-G significantly enhances cardiac tissue stimulation. Injection of PAMB-G into the stimulating electrode location at the myocardium has a 4 times greater reduction of pacing threshold voltage, compared with electrode-only or gelatin-injected tissues. Multi-electrode array mapping reveals that the cardiac conduction velocity of PAMB-G group is significantly faster than the non- or gelatin-injection groups. PAMB-G also reduces pacing threshold voltage in an adenosine-induced atrial-ventricular block rat model. Conclusion: PAMB-G hydrogel reduces cardiac pacing threshold voltage, which is able to enhance pacemaker efficacy.

Safety and Efficacy of Arterially Directed Liver Therapies in the Treatment of Hepatic Metastatic Ovarian Cancer: A Retrospective Single-Institution Study.

PURPOSE: To evaluate the safety and efficacy of 2 locoregional therapies (LRTs) including hepatic artery embolization (HAE) and transarterial radioembolization (TARE) in the treatment of patients with metastatic ovarian cancer to the liver. MATERIAL AND METHODS: From October 2010 to May 2019, the data of 15 consecutive patients (median age, 54 years ± 9.8; range, 35-78 years) with hepatic metastatic ovarian cancer who were treated with either HAE (n = 6; 40%) or TARE (n = 9; 60%) were reviewed. The most common histopathologic type was epithelial ovarian carcinoma (80%). The most common chemotherapy regimens used prior to embolization included carboplatin, paclitaxel, cisplatin, and bevacizumab. Patients received a mean of 4 lines ± 3 (range, 1-9) of chemotherapy. All patients with serous carcinoma were resistant to platinum at the time of embolization. Indications for embolization were progression of disease to the liver while receiving chemotherapy in 14 (93.3%) patients and palliative pain control in 1 patient. RESULTS: The overall response rates at 1, 3, and 6 months were 92.4%, 85.6%, and 70%, respectively. Median overall survival from the time of LRT was 9 (95% confidence interval [CI], 4-14) months. Median local tumor progression was 6.4 months ± 5.03 (95% CI, 3.3-9.5). No grade 3-5 adverse events were detected in either group. CONCLUSIONS: HAE and TARE were well tolerated in patients with metastatic ovarian cancer to the liver and possibly ensured prolonged disease control in heavily treated, predominantly in patients resistant to platinum. Larger numbers are needed to verify these data.

Transarterial Embolization of Liver Cancer in a Transgenic Pig Model.

PURPOSE: To develop and characterize a porcine model of liver cancer that could be used to test new locoregional therapies. MATERIALS AND METHODS: Liver tumors were induced in 18 Oncopigs (transgenic pigs with Cre-inducible TP53R167H and KRASG12D mutations) by using an adenoviral vector encoding the Cre-recombinase gene. The resulting 60 tumors were characterized on multiphase contrast-enhanced CT, angiography, perfusion, micro-CT, and necropsy. Transarterial embolization was performed using 40-120 µm (4 pigs) or 100-300 µm (4 pigs) Embosphere microspheres. Response to embolization was evaluated on imaging. Complications were determined based on daily clinical evaluation, laboratory results, imaging, and necropsy. RESULTS: Liver tumors developed at 60/70 (86%) inoculated sites. Mean tumor size was 2.1 cm (range, 0.3-4 cm) at 1 week. Microscopically, all animals developed poorly differentiated to undifferentiated carcinomas accompanied by a major inflammatory component, which resembled undifferentiated carcinomas of the human pancreatobiliary tract. Cytokeratin and vimentin expression confirmed epithelioid and mesenchymal differentiation, respectively. Lymph node, lung, and peritoneal metastases were seen in some cases. On multiphase CT, all tumors had a hypovascular center, and 17/60 (28%) had a hypervascular rim. After transarterial embolization, noncontrast CT showed retained contrast medium in the tumors. Follow-up contrast-enhanced scan showed reduced size of tumors after embolization using either 40-120 µm or 100-300 µm Embosphere microspheres, while untreated tumors showed continued growth. CONCLUSIONS: Liver tumors can be induced in a transgenic pig and can be successfully treated using bland embolization.

Intravesical Prostatic Protrusion Does Not Influence the Efficacy of Prostatic Artery Embolization.

PURPOSE: To compare the outcomes of prostatic artery embolization (PAE) in patients with different intravesical prostatic protrusion (IPP) grades. MATERIALS AND METHODS: This retrospective single-center study included 128 patients (aged 50-86 years) who underwent PAE from 2013 to 2017. IPP grades were classified as follows: grade I (<10 mm), grade II (10-19 mm), and grade III (≥20 mm). Nineteen patients (14.8%) had grade I [mean IPP 7.8 mm, prostatic volume (PV) 64.1 cm3], 77 (60.2%) had grade II (mean IPP 14.9 mm, PV 87.0 cm3), and 32 (25%) had grade III (mean IPP 26.2 mm, PV 132.6 cm3), P < .01. The outcomes, including PV, international prostate symptom score (IPSS), and quality of life (QoL), were compared between the IPP grades at the 12-month follow-up. Clinical failure was defined as IPSS >7 or QoL >2. RESULTS: IPP decreased (I: -8.2%, II: -27.3%, and III: -38.7%, P = .01), and all other endpoints improved (P < .01). Adjusted covariance analysis, considering baseline PV as a confounding factor, showed no correlation between the 12-month outcomes and baseline IPP. Clinical failure was observed in 17/128 patients (13.3%) and was similar in prevalence among the IPP groups (P = .20). Minor complications occurred in 43 patients (33.6%) and major in 3 (2.3%). There were statistical differences in the complications between IPP grades II and III (P < .01). CONCLUSIONS: PAE was similarly effective in all the IPP grades at the 12-month follow-up, and there was no difference in the clinical failure between the groups. Complications in IPP grade III were more frequent than those in IPP grade II.

Crosstalk between microglia and patient-derived glioblastoma cells inhibit invasion in a three-dimensional gelatin hydrogel model.

BACKGROUND: Glioblastoma is the most common and deadly form of primary brain cancer, accounting for more than 13,000 new diagnoses annually in the USA alone. Microglia are the innate immune cells within the central nervous system, acting as a front-line defense against injuries and inflammation via a process that involves transformation from a quiescent to an activated phenotype. Crosstalk between GBM cells and microglia represents an important axis to consider in the development of tissue engineering platforms to examine pathophysiological processes underlying GBM progression and therapy. METHODS: This work used a brain-mimetic hydrogel system to study patient-derived glioblastoma specimens and their interactions with microglia. Here, glioblastoma cells were either cultured alone in 3D hydrogels or in co-culture with microglia in a manner that allowed secretome-based signaling but prevented direct GBM-microglia contact. Patterns of GBM cell invasion were quantified using a three-dimensional spheroid assay. Secretome and transcriptome (via RNAseq) were used to profile the consequences of GBM-microglia interactions. RESULTS: Microglia displayed an activated phenotype as a result of GBM crosstalk. Three-dimensional migration patterns of patient-derived glioblastoma cells showed invasion was significantly decreased in response to microglia paracrine signaling. Potential molecular mechanisms underlying with this phenotype were identified from bioinformatic analysis of secretome and RNAseq data. CONCLUSION: The data demonstrate a tissue engineered hydrogel platform can be used to investigate crosstalk between immune cells of the tumor microenvironment related to GBM progression. Such multi-dimensional models may provide valuable insight to inform therapeutic innovations to improve GBM treatment.

Gelatin methacryloyl hydrogel eye pad loaded with amniotic extract prevents symblepharon in rabbit eyes.

OBJECTIVE: The aim was to evaluate the ability of gelatin methacryloyl (GelMA) hydrogel eye pads loaded with amniotic extract to prevent symblepharon in rabbits. MATERIALS AND METHODS: Forty-eight rabbits were divided into 3 groups. After ocular alkali burn, Group A (n=16) was treated with amniotic extract-loaded hydrogel eye pads placed in the conjunctival sac, Group B (n=16) was treated with amniotic membrane transplantation, and Group C (n=16) received no treatment. At 1, 2, 3, and 4 weeks post-injury, 4 rabbits from each group were selected to evaluate for symblepharon, determine epithelial healing rate and corneal neovascularization, conduct histopathology, and to quantify the expression of TGF-ß1. RESULTS: At 1 week post-injury, the epithelial healing rate in Groups A and B was higher than Group C (p=0.002, 0.001, respectively). At 2 weeks, corneal neovascularization in Group B was less than Group C (p=0.004). At 3 and 4 weeks, no symblepharon has been found in Group A, but it was found in some eyes in Group B and C (p=0.009, 0.013). Further, the expression of TGF-ß1 in Group A was lower than in Group B and C (p<0.001). H&E staining showed that the controls in Group C had more edema and inflammatory cell infiltration in the first 2 weeks, relative to Groups A and B. At 4 weeks, Masson's Trichrome staining showed that fibers were most regularly aligned in Group A and that immuno-histochemical staining found that proliferating cell nuclear antigen was highest expressed in Group C. CONCLUSIONS: Treatment with GelMA hydrogel eye pads loaded with amniotic extract shortly after chemical injury prevented symblepharon in rabbits.

Mussel-inspired antimicrobial gelatin/chitosan tissue adhesive rapidly activated in situ by H2O2/ascorbic acid for infected wound closure.

The development of minimally invasive surgery has created a demand for ideal medical adhesives exhibiting biocompatibility, biodegradability, antimicrobial activity, and strong adhesion to tissues in wet environments. However, as clinically approved surgical tissue glues suffer from poor adhesion activation, limited adhesion strength, and toxicity, novel tissue glues are highly sought after. Herein, a mussel-inspired injectable hydrogel was prepared from catechol- and methacrylate-modified chitosan/gelatin and shown to exhibit biocompatibility, inherent antimicrobial activity, and good adhesion to wet tissues. Moreover, as this gel could be applied onto tissue surfaces and cured in situ within seconds of body contact by a biocompatible and multifunctional redox initiator (H2O2-ascorbic acid), it was concluded to be a promising surgical sealant and wound dressing (even for infected wounds) accelerating wound healing.

Three-Dimensional Augmented Reality Visualization Informs Locoregional Therapy in a Translational Model of Hepatocellular Carcinoma.

PURPOSE: To evaluate the utility of visualizing preprocedural MR images in 3-dimensional (3D) space using augmented reality (AR) before transarterial embolization of hepatocellular carcinoma (HCC) in a preclinical model. MATERIALS AND METHODS: A total of 28 rats with diethylnitrosamine-induced HCCs > 5 mm treated with embolization were included in a prospective study. In 12 rats, 3D AR visualization of preprocedural MR images was performed before embolization. Procedural metrics including catheterization time and radiation exposure were compared vs a prospective cohort of 16 rats in which embolization was performed without AR. An additional cohort of 15 retrospective cases was identified and combined with the prospective control cohort (n = 31) to improve statistical power. RESULTS: A 37% reduction in fluoroscopy time, from 11.7 min to 7.4 minutes, was observed with AR when compared prospectively, which did not reach statistical significance (P = .12); however, when compared with combined prospective and retrospective controls, the reduction in fluoroscopy time from 14.1 min to 7.4 minutes (48%) was significant (P = .01). A 27% reduction in total catheterization time, from 42.7 minutes to 31.0 minutes, was also observed with AR when compared prospectively, which did not reach statistical significance (P = .11). No significant differences were seen in dose-area product or air kerma prospectively. CONCLUSIONS: Three-dimensional AR visualization of preprocedural imaging may aid in the reduction of procedural metrics in a preclinical model of transarterial embolization. These data support the need for further studies to evaluate the potential of AR in endovascular oncologic interventions.

Injectable and in situ crosslinkable gelatin microribbon hydrogels for stem cell delivery and bone regeneration in vivo.

Rationale: Injectable matrices are highly desirable for stem cell delivery. Previous research has highlighted the benefit of scaffold macroporosity in enhancing stem cell survival and bone regeneration in vivo. However, there remains a lack of injectable and in situ crosslinkable macroporous matrices for stem cell delivery to achieve fast bone regeneration in immunocompetent animal model. The goal of this study is to develop an injectable gelatin-based µRB hydrogel supporting direct cell encapsulation that is available in clinics as macroporous matrices to enhance adipose-derived stromal cell (ASC) survival, engraftment and accelerate bone formation in craniofacial defect mouse. Methods: Injectable and in situ crosslinkable gelatin microribbon (µRB)-based macroporous hydrogels were developed by wet-spinning. Injectability was optimized by varying concentration of glutaraldehyde for intracrosslinking of µRB shape, and fibrinogen coating. The efficacy of injectable µRBs to support ASCs delivery and bone regeneration were further assessed in vivo using an immunocompetent mouse cranial defect model. ASCs survival was evaluated by bioluminescent imaging and bone regeneration was assessed by micro-CT. The degradation and biocompatibility were determined by histological analysis. Results: We first optimized injectability by varying concentration of glutaraldehyde used to fix gelatin µRBs. The injectable µRB formulation were subsequently coated with fibrinogen, which allows in situ crosslinking by thrombin. Fluorescence imaging and histology showed majority of µRBs degraded by the end of 3 weeks. Injectable µRBs supported comparable level of ASC proliferation and bone regeneration as implantable prefabricated µRB controls. Adding low dosage of BMP2 (100 ng per scaffold) with ASCs substantially accelerated the speed of mineralized bone regeneration, with 90% of the bone defect refilled by week 8. Immunostaining showed M1 (pro-inflammatory) macrophages were recruited to the defect at day 3, and was replaced by M2 (anti-inflammatory) macrophages by week 2. Adding µRBs or BMP2 did not alter macrophage response. Injectable µRBs supported vascularization, and BMP-2 further enhanced vascularization. Conclusions: Our results demonstrated that µRB-based scaffolds enhanced ASC survival and accelerated bone regeneration after injection into critical sized cranial defect mouse. Such injectable µRB-based scaffold can provide a versatile biomaterial for delivering various stem cell types and enhancing tissue regeneration.