TY  - JOUR
A1  - Lorson, Thomas
A1  - Ruopp, Matthias
A1  - Nadernezhad, Ali
A1  - Eiber, Julia
A1  - Vogel, Ulrich
A1  - Jungst, Tomasz
A1  - Lühmann, Tessa
T1  - Sterilization Methods and Their Influence on Physicochemical Properties and Bioprinting of Alginate as a Bioink Component
JF  - ACS Omega
N2  - Bioprinting has emerged as a valuable threedimensional (3D) biomanufacturing method to fabricate complex hierarchical cell-containing constructs. Spanning from basic research to clinical translation, sterile starting materials are crucial. In this study, we present pharmacopeia compendial sterilization methods for the commonly used bioink component alginate. Autoclaving (sterilization in saturated steam) and sterile filtration followed by lyophilization as well as the pharmacopeia non-compendial method, ultraviolet (UV)-irradiation for disinfection, were assessed. The impact of the sterilization methods and their effects on physicochemical and rheological properties, bioprinting outcome, and sterilization efficiency of alginate were detailed. Only sterile filtration followed by lyophilization as the sterilization method retained alginate's physicochemical properties and bioprinting behavior while resulting in a sterile outcome. This set of methods provides a blueprint for the analysis of sterilization effects on the rheological and physicochemical pattern of bioink components and is easily adjustable for other polymers used in the field of biofabrication in the future.
KW  - hydrogels
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229460
N1  - Lizenz: https://pubs.acs.org/page/policy/authorchoice_termsofuse.html
VL  - 5
IS  - 12
ER  - 
TY  - JOUR
A1  - Lübtow, Michael M.
A1  - Lorson, Thomas
A1  - Finger, Tamara
A1  - Gröber-Becker, Florian-Kai
A1  - Luxenhofer, Robert
T1  - Combining Ultra-High Drug-Loaded Micelles and Injectable Hydrogel Drug Depots for Prolonged Drug Release
JF  - Macromolecular Chemistry and Physics
N2  - Hydrogel‐based drug depot formulations are of great interest for therapeutic applications. While the biological activity of such drug depots is often characterized well, the influence of incorporated drug or drug‐loaded micelles on the gelation properties of the hydrogel matrix is less investigated. However, the latter is of great importance from fundamental and application points of view as it informs on the physicochemical interactions of drugs and water‐swollen polymer networks and it determines injectability, depot stability, as well as drug‐release kinetics. Here, the impact of incorporated drug, neat polymer micelles, and drug‐loaded micelles on the viscoelastic properties of a cytocompatible hydrogel is investigated systematically. To challenge the hydrogel with regard to the desired application as injectable drug depot, curcumin (CUR) is chosen as a model compound due to its very low‐water solubility and limited stability. CUR is either directly solubilized by the hydrogel or pre‐incorporated into polymer micelles. Interference of CUR with the temperature‐induced gelation process can be suppressed by pre‐incorporation into polymer micelles forming a binary drug delivery system. Drug release from a collagen matrix is studied in a trans‐well setup. Compared to direct injection of drug formulations, the hydrogel‐based systems show improved and extended drug release over 10 weeks.
KW  - curcumin
KW  - drug depots
KW  - drug-loaded hydrogels
KW  - poly(2-oxazine)
KW  - sustained release
KW  - poly(2- oxazoline)
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208115
VL  - 221
IS  - 1
ER  -