Engineering Natural Pollen Grains as Multifunctional 3D Printing Materials

Abstract

The development of multifunctional 3D printing materials from sustainable natural resources is a high priority in additive manufacturing. Using an eco-friendly method to transform hard pollen grains into stimulus-responsive microgel particles, we engineered a pollen-derived microgel suspension that can serve as a functional reinforcement for composite hydrogel inks and as a supporting matrix for versatile freeform 3D printing systems. The pollen microgel particles enabled the printing of composite inks and improved the mechanical and physiological stabilities of alginate and hyaluronic acid hydrogel scaffolds for 3D cell culture applications. Moreover, the particles endowed the inks with stimulus-responsive controlled release properties. The suitability of the pollen microgel suspension as a supporting matrix for freeform 3D printing of alginate and silicone rubber inks was demonstrated and optimized by tuning the rheological properties of the microgel. Compared with other classes of natural materials, pollen grains have several compelling features, including natural abundance, renewability, affordability, processing ease, monodispersity, and tunable rheological features, which make them attractive candidates to engineer advanced materials for 3D printing applications.

Topography‐Supported Nanoarchitectonics of Hybrid Scaffold for Systematically Modulated Bone Regeneration and Remodeling

“…The process was rapidly repeated, eventually yielding a femur-specific orthopedic implant. [48] Subsequently, the composite implants were fabricated using PEEK filaments reinforced with different amounts of TiO 2 nanoparticles. The polydopamine derivatives, unreacted dopamine, and any impurities, which can cause unexpected metabolic disorders and neural system malfunctions, were degraded under a high-temperature heat treatment, leaving only the TiO 2 reinforcement and PEEK matrix.…”

Regulable Supporting Baths for Embedded Printing of Soft Biomaterials with Variable Stiffness

“…Besides, a 527 nm wavelength laser was used to excite beads. Four gauge sets of nozzles with 38 mm length (22,23,25, and 27 gauges with 0.68, 0.59, 0.48, and 0.37 mm outer diameters) were selected. The translation velocity was set to 3, 6, 12, and 20 mm/s, respectively.…”

“…It not only allows the omnidirectional deposition of bioink during printing but also holds the bioink in place until the structure fully solidifies. An ideal supporting bath should have regulable rheological properties, biocompatibility, steadiness, and ease of removal, which are favorable to printing performance. , …”

“…An ideal supporting bath should have regulable rheological properties, biocompatibility, steadiness, and ease of removal, which are favorable to printing performance. 23,24 Based on the morphology of their basic units, current supporting baths could be roughly classified into two types: granular microgel baths and bulk gel baths. 15 The granular microgel bath consists of a large number of microgels, the slippage and reconstruction of which provide the yield stress and self-recovery behavior to support embedded printing.…”

Pollen‐Based Magnetic Microrobots are Mediated by Electrostatic Forces to Attract, Manipulate, and Kill Cancer Cells

“…However, the hollow internal shells of pollen microparticles can be used for cargo encapsulation and delivery recently reported by our previous research. [32][33][34][35][36][37] Moreover, pollen microparticles have been used as 3D scaffolds, [38] paper derived from pollen microgels, [39] pressure sensors, [40] biosensor platform, [41] flexible pollen-derived substrate for optoelectronic applications, [42] and water cleaning. [17,18,43] On the other hand, pollen microparticles are dynamic entities capable of communicating with other cells by electrostatic forces.…”