Marije Sloff

The use of bowel tissue for urinary diversion can be associated with severe complications, and regenerative medicine may circumvent this by providing an engineered conduit. In this study, a novel tubular construct was identified for this purpose. Three constructs (diameter 15 mm) were prepared from type I collagen and either (a) a semi-biodegradable Vypro II polymer (COL-Vypro), (b) a rapidly biodegradable Vicryl polymer (COL-Vicryl) or (c) an additional collagenous layer (COL-DUAL). After freezing, lyophilization and crosslinking, all constructs showed a porous structure with a two-fold higher strength for the polymer-containing constructs. These constructs were connected to full bladder defects of 11 female pigs and evaluated after 1 (n = 4) or 3 months (n = 5). With respect to surgical handling, the polymer-containing constructs were superior. All pigs voided normally without leakage and the survival rate was 82%. For the implanted COL-Vypro constructs (8/9), stone formation was observed. COL-DUAL and COL-Vicryl showed better biocompatibility and only small remnants were found 1 month post-implantation. Histological and immunohistochemical analysis showed the best regeneration for COL-Vicryl with respect to urothelium; muscle pedicles and elastin formation were best developed in the COL-Vicryl constructs. In this study, COL-Vicryl constructs were superior in both biocompatibility and bladder tissue regeneration and have high potential for artificial urinary diversions. Copyright © 2016 John Wiley & Sons, Ltd.

On review of the use of stem cells in the literature, promissory outcomes for functional organ recovery in many subspecialties in medicine underscore its therapeutic potential. The application of stem cells through the use of a needle can result in additional scar formation, which is undesired for delicate organs. The present work describes the use of a needle-less stem cell injector with the Immediate Drop on Demand Technology (I-DOT) for cell injection in vitro. Mesenchymal stromal cells from human bone marrow were labeled with ethynyl-deoxyuridine (EdU) for 2 days and then were re-suspended. With the use of I-DOT, the cells were applied to type 1 collagen matrices or pig bladder tissue specimens with or without mucosa at different levels of energy. The collagen matrices were analyzed after 4 h and 5 days; bladder tissue specimens were analyzed 4 h after cell implantation. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT) assay was performed immediately after cell application to the collagen matrices. Histological analysis with the use of frozen sections and immunofluorescence was used to localize EdU-labeled cells. A considerable number of cells were detected by use of the MTT assay for collagen matrices. In the collagen matrix, the mean measured depth immediately after application ranged between 210 μm and 489 μm, 220 μm and 270 μm for entire bladder specimens, and 230 μm and 370 μm for bladder without mucosa. Cells survived for up to 5 days in the collagen matrix in both bladder specimens. Cells can survive during I-DOT application, which suggests that the I-DOT device may be a potentially suitable technology for needle-less cell application onto tissues.

Treatment of collagen scaffolds with salts taken from the Hofmeister series induce fast shrinkage and increased stiffness. Subcutaneous implantation in rats shows similar biocompatibility as control scaffolds, but reduced cellular influx and increased structural integrity.

On review of the use of stem cells in the literature, promissory outcomes for functional organ recovery in many subspecialties in medicine underscore its therapeutic potential. The application of stem cells through the use of a needle can result in additional scar formation, which is undesired for delicate organs. The present work describes the use of a needle-less stem cell injector with the Immediate Drop on Demand Technology (I-DOT) for cell injection in vitro. Mesenchymal stromal cells from human bone marrow were labeled with ethynyl-deoxyuridine (EdU) for 2 days and then were re-suspended. With the use of I-DOT, the cells were applied to type 1 collagen matrices or pig bladder tissue specimens with or without mucosa at different levels of energy. The collagen matrices were analyzed after 4 h and 5 days; bladder tissue specimens were analyzed 4 h after cell implantation. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test (MTT) assay was performed immediately after cell application to the collagen matrices. Histological analysis with the use of frozen sections and immunofluorescence was used to localize EdU-labeled cells. A considerable number of cells were detected by use of the MTT assay for collagen matrices. In the collagen matrix, the mean measured depth immediately after application ranged between 210 μm and 489 μm, 220 μm and 270 μm for entire bladder specimens, and 230 μm and 370 μm for bladder without mucosa. Cells survived for up to 5 days in the collagen matrix in both bladder specimens. Cells can survive during I-DOT application, which suggests that the I-DOT device may be a potentially suitable technology for needle-less cell application onto tissues.

Releasibility of doxorubicin from drug‐conjugates is believed to be a prerequisite for its anti‐cancer activity. Here, a new glyco‐drug approach that circumvents the releasibility restriction is reported, opening a new possibility to design efficient, target specific drug delivery system. It is discovered that stable amide coupling of doxorubicin (DOX) tohyaluronan (HA) shows dose dependent cytotoxicity to CD44 positive human coloncancer cells (HCT116) as compared to human breast cancer cells(MCF‐7) and mouse fibroblast cells (NIH‐3T3), which express less CD44 receptor. This direct conjugation approach is an easy scalable strategy that could be adopted to design innocuous anti‐tumor nanoparticle formulations.