In the last few years, several strategies have been proposed to fabricate scaffolds for tissue engineering (TE) applications; however, they are based on harsh and time‐consuming techniques. The choice for natural polymers such as cashew gum (CG) allows to circumvent the demands of biocompatibility and degradability of TE systems. In this work, CG, a polysaccharide derived from Anacardium occidentale trees, is functionalized with aldehyde groups through periodate oxidation. The resultant oxidized cashew gum (CGO) is mixed with gelatin (GE) to yield a covalently crosslinked hydrogel. CGO/GE sponges are obtained by employing a freeze‐drying methodology to the previously obtained hydrogels. The mechanical properties, swelling ability, and porosity of the GE/CGO sponges are tuned by using CGO with different degrees of oxidation. The resultant sponges can maintain high levels of water absorption and recover their initial mechanical properties after cyclic compression. Moreover, these porous and mechanically robust devices can support the adhesion and proliferation of cells, which can envision their application for the regeneration of soft tissues.

ResumoEsferas de goma do cajueiro carboximetilada e quitosana foram produzidas via complexação polieletrolítica. As esferas foram modificadas quimicamente de modo a obter-se sistemas estáveis em meio ácido e que apresentassem uma resposta de intumescimento diferenciado frente à variação de pH. As esferas foram modificadas por reacetilação da quitosana e por reticulação com epicloridrina, glutaraldeído e genipina. As esferas reticuladas foram caracterizadas por meio de técnicas como: espectroscopia de absorção no infravermelho, análise termogravimétrica, microscopia eletrônica de varredura e quanto à solubilidade em pH 1,2 e ao intumescimento. As esferas de goma do cajueiro carboximetilada e quitosana reacetilada, e as esferas reticuladas com epicloridrina apresentaram baixa resistência à dissolução em pH 1,2. Entretanto, as esferas reticuladas com glutaraldeído e genipina apresentaram resistência à dissolução e baixo coeficiente de difusão. As esferas reticuladas com genipina apresentaram um grau de intumescimento maior do que as esferas reticuladas com glutaraldeído nas concentrações de 3% e 5% (massa/volume). As esferas reticuladas com genipina apresentaram intumescimento responsivo à variação de pH e estabilidade em pH 1,2, indicando que esses sistemas possuem potencial para uso em sistemas de liberação controlada de fármacos por via oral. PalavrasTchave: goma do cajueiro, carboximetilação, quitosana, reticulação. AbstractChitosan/carboxymethylated cashew gum beads were produced via polyelectrolytic complexation. The beads were chemically modified to achieve stable acidic medium and to provide a swelling response in different pH. The beads were modified by chitosan reacetylation and by crosslinking with epichlorohydrin, glutaraldehyde and genipin. The beads were characterized by techniques such as: infrared spectroscopy, thermogravimetry, scanning electron microscopy and regarding their solubility at pH 1.2 and swelling. The beads of carboxymethyl cashew gum and reacetylated chitosan and those crosslinked with epichlorohydrin had low resistances to dissolution at pH 1.2. However, the beads crosslinked with glutaraldehyde and genipin showed resistance to dissolution along with low diffusion coefficients. Moreover, beads crosslinked with genipin presented a higher degree of swelling than beads crosslinked with glutaraldehyde at concentrations of 3% and 5% (weight/volume). Beads crosslinked with genipin presented responsive behavior to pH variation and stability at pH 1.2, indicating that these systems have potential for use in controlled drug delivery systems for oral administration.