Multilayered membranes with tuned well arrays to be used as regenerative patches

Abstract

Flexible multilayered membranes containing multiple micro-reservoirs are found as potential regenerative patches. Layer-by-layer (LbL) methodology over a featured PDMS substrate is used to produce patterned membranes, composed only by natural-based polymers, that can be easily detached from the PDMS substrate. The combination of nano-scale control of the polymeric organization along the thickness of the chitosan/alginate (CHT/ALG) membranes, provided by LbL, together with the geometrical micro-scale features of the patterned membranes offers a uniqueness system that allows cells to colonize 3-dimensionally. This study provides a promising strategy to control cellular spatial organization that can face the region of the tissue to regenerate.

Green approaches for extraction, chemical modification and processing of marine polysaccharides for biomedical applications

“…The LbL assembly process is a rather time-consuming methodology when compared with the aforementioned methodologies but enables the incorporation of multicomponents and, thus, multifunctionalities in a single membrane and a better control in thickness. Smooth flat hydrophobic and hydrophilic non-patterned or patterned inert templates have been used to produce biocompatible multilayered films, with well-defined structures, compositions, and thicknesses at the nanoscale by repeating their alternate immersion in aqueous solutions of at least two oppositely charged marine polysaccharides via dip-assisted LbL assembly methodology ( Larkin et al, 2010 ; Caridade et al, 2013 , 2015 ; Silva et al, 2014 ; Martins et al, 2017 ; Sousa et al, 2017 ). In the end of the assembly process, the multilayered films are easily detached into robust and easily handled free-standing multilayered membranes whose nanotopography recreates the substrate’s features.…”

“…with permission from John Wiley & Sons, Copyright 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim; (B) Freestanding multilayered membranes patterned with micro-wells, wherein cells tended to colonize preferentially. Adapted from ( Martins et al, 2017 ) with permission from Elsevier, Copyright 2017.…”

“…More recently, flat patterned templates have gained momentum due to the need to produce bioinstructive patterned freestanding membranes that could recreate not only the structural but also the topographical features of highly aligned tissues, such as bone or nervous tissue, enabling a better regulation of cell functions. Micro-patterned polydimethylsiloxane substrates have been used to produce (CHT/ALG)100 free-standing membranes denoting a well-defined array of geometrical features at the microscale in which osteoblast-like cells tended to colonize preferentially ( Figure 4B ), holding great promise as micro-reservoirs of therapeutic agents or as cell carriers in bone tissue regeneration ( Martins et al, 2017 ). More recently, nanogrooved CHT/CS freestanding membranes assembled onto nanopatterned polycarbonate substrates guided C2C12 myoblast cells’ alignment along the nanopattern direction and triggered their differentiation into myotubes ( Sousa et al, 2017 ).…”

Ionotropic Gelation of Chitosan Flat Structures and Potential Applications

“…Chit polymer satisfies all the required propertie wound dressings: biocompatibility, non-toxicity, biodegradability, defined stru good mechanical strength, high transport of gases, nutrients, proteins and cells [7 popular example of a flat chitosan membrane in wound dressing comes from the Con ® hemostatic bandage prepared by solution casting [73]. Furthermore, a novel co of chitosan-based flexible membrane was proposed in 2017 [74] by using LBL syn on a patterned PDMS substrate. The membrane possesses a well-arranged porous ture to accommodate cell culture on one side, as shown in Figure 5a, and a dense lay the other side that prevents bacterial invasion while allowing transpiration.…”

Unveiling the Assembly of Neutral Marine Polysaccharides into Electrostatic-Driven Layer-by-Layer Bioassemblies by Chemical Functionalization

“…Those include their biocompatibility, biodegradability, non-toxicity, non-immunogenic, antitumoral and anticoagulant properties, chemical versatility, and wide availability [ 27 , 28 ]. For instance, chitosan (CHT), a positively charged natural biopolymer obtained by the deacetylation of chitin extracted from crab and shrimp shells, has been extensively combined with structurally similar yet oppositely charged polysaccharides [ 17 , 29 , 30 ], proteins [ 31 , 32 ], and even other biomolecules [ 33 ], in order to shape a plethora of LbL structures that hold great potential to be applied in the biomedical arena. However, to the best of our knowledge, the assembly of neutral marine polysaccharides into LbL biostructures has not been exploited to date, despite their wide abundance and variety, easy functionality, and invaluable potential in the biomedical and biotechnological fields.…”