Takuya Kitaoka

Professor, Ph.D.
E-mail: tkitaoka@agr.kyushu-u.ac.jp

Laboratory of Bioresources Chemistry, Department of Agro-Environmental Sciences,
Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, JAPAN
Academic Staff Educational and Research Activities Database of Kyushu University

Admission Information
International Undergraduate Program (IUP)
International Graduate program (IGP)

Associate Member of the Science Council of Japan
Publication list

Bioadaptive Nanoarchitectonics

Bio-inspired Nanoarchitectonics of Polysaccharide Nanofibers for Biomedical Engineering

Supramolecular nanoarchitectures of natural structural polysaccharides such as cellulose and chitin have recently attracted considerable attention as smart nanobiomaterials from both bioengineering and nanoengineering perspectives. Cellulose (β‑1,4‑linked D‑glucopyranose), the main constituent of plant cell walls, is the most abundant and renewable bioresource. Chitin and chitosan, structural analogues of cellulose, possess various biological functions. These polysaccharides exhibit unique features that enable hierarchical organization through self‑assembly, resulting in crystalline nanofiber structures.
Importantly, nano‑organized polysaccharide nanofibers provide a bioinspired platform that recapitulates key features of fibrillar collagen and biological polysaccharides found in human extracellular matrices, thereby bridging natural polysaccharide architectures with human tissue microenvironments. We have pursued the development of novel bioadaptive biomaterials for cell and tissue engineering in regenerative medicine and immunological modulation for materials therapy by focusing on the bioadaptive nanoarchitectures of nano‑organized polysaccharide nanofibers.

Strategic Design of Forest and Marine Nanofibers for Bioadaptive Cell Culture Scaffolds

Extracellular matrix (ECM), serving as a structural and biochemical scaffold for surrounding cells, plays crucial roles in cell adhesion, proliferation, and differentiation in vivo. We have investigated in vitro cell culture and cellular regulation using structural nanofiber‑based scaffolds composed of surface‑modified cellulose and chitin nanofibers. Although cellulose is inherently bioinert, surface carboxylation, sulfation (sulfate half‑ester), and phosphorylation of cellulose nanofibers drastically enhance cell attachment and growth in fibroblasts, myoblasts, osteoblasts, keratinocytes, hepatocytes, monocytes, macrophages, and various stem cells, including mesenchymal stem cells and dental pulp stem cells.
Notably, these nano‑organized polysaccharide nanofiber scaffolds enable robust expansion of primary human mesenchymal stem cells under completely xeno‑free conditions, demonstrating their exceptional bioadaptivity and clinical applicability. Furthermore, combining forest‑derived and marine‑derived nanofibers enables the regulation of cellular behavior and functions in vitro, contributing to advances in regenerative medicine. Rigid nanofiber nanoarchitectures with native crystalline forms and regularly repeated functional groups improve cellular microenvironments and offer strong potential for developing bioadaptive cell culture scaffolds with ECM‑like functions.

Architectural Build-up Using Nano-Polysaccharides via Pickering Emulsion Templating and 3D Bioprinting

Three‑dimensional cell culture scaffolds with tunable pore sizes and customizable functionalities have recently gained significant attention for providing improved microenvironments that support cell adhesion, proliferation, and long‑term survival. We have explored the fabrication of low‑internal‑phase Pickering‑emulsion‑induced porous scaffolds using cellulose and chitosan nanofibers. Natural nanofiber‑stabilized Pickering emulsions exhibit high physical stability and aligned porous architectures suitable for creating favorable microenvironments for human hepatocellular carcinoma HepG2 cells, enabling spheroid formation that mimics the lobular architecture of the human liver.
These natural nanofiber‑based foams represent a promising green and sustainable approach to expanding bioadaptive scaffolds for cell engineering, and they offer compatibility with emerging 3D‑printing strategies for advanced scaffold design. Furthermore, recent studies using nano‑organized polysaccharides have demonstrated enhanced undifferentiated expansion of human mesenchymal stem cells through cell‑packaging technologies, highlighting new possibilities for large‑scale stem cell manufacturing.

Immunomodulatory and Adjuvant Functions of Polysaccharide Nanofibers

Natural polysaccharide nanofibers derived from forest and marine biomass exhibit unique immunological activities that originate from their nanoscale architecture and regularly aligned surface functional groups. We have investigated the immunomodulatory functions of cellulose and chitin/chitosan nanofibers, focusing on their ability to activate innate immune pathways and regulate inflammatory responses. Surface‑engineered chitin nanofibers, in particular, can activate Toll‑like receptor 2 (TLR2) and modulate cytokine secretion in monocytes and macrophages, demonstrating their potential as bioadaptive immunomodulatory materials. Furthermore, polysaccharide nanofibers with controlled morphology and charge density can function as structural adjuvants, enhancing antigen presentation and promoting desirable immune polarization. These findings highlight the emerging concept of “materials‑driven immunomodulation,” in which the intrinsic nanoarchitecture of polysaccharide nanofibers contributes directly to immune regulation. Such bioadaptive immunomaterials offer promising opportunities for vaccine adjuvants, inflammation control, and next‑generation materials therapy.

Interfacial Nanoarchitectonics

Ecosystems Materiology: Polysaccharide Nanoarchitectures for Long-Term Materials Circulation

Ecosystems Materiology is an emerging concept that repositions natural polysaccharide nanomaterials within the long-term circulation of ecosystems rather than short-term industrial use. Forest-derived polysaccharides such as cellulose and lignin possess highly ordered nanoarchitectures that are synthesized through biological processes powered by atmospheric carbon. These structural polysaccharides represent one of the most sustainable material platforms on Earth, yet their potential has long been constrained by conventional bulk uses such as paper, textiles, and construction materials.
To achieve a truly carbon-neutral and ecosystem-compatible society, polysaccharide-based materials must be designed not only for low environmental impact but also for functional integration into ecological cycles. This requires materials that (i) originate from renewable biomass, (ii) exhibit advanced functions derived from their native nanoarchitectures, and (iii) return to ecosystems through controlled biodegradation without generating microplastic pollution.
Our research focuses on the interfacial nanoarchitectonics of cellulose nanofibers, lignin precursors, and their hybrid assemblies to create next-generation ecosystem materials. By leveraging their crystalline nanofiber structures, amphiphilic interfaces, and self-organizing capabilities, we aim to develop functional materials that contribute to long-term carbon circulation, sustainable agriculture, and environmentally harmonized material technologies.

Wood-Mimetic Microspheres via Pickering Emulsion Nanoarchitectonics

Forest‑derived polysaccharides possess hierarchical nanoarchitectures that inspire the design of wood‑mimetic microspheres. Using cellulose nanofibers and lignin precursors as solid surfactants, we fabricate uniform spherical and hollow microparticles through Pickering emulsion templating.Enzymatic polymerization of lignin monomers enables the formation of core–shell structures that resemble the layered architecture of woody cell walls. These biodegradable microspheres serve as sustainable alternatives to synthetic microbeads and provide tunable interfacial, mechanical, and dispersibility properties for cosmetic, environmental, and agricultural applications within ecosystem‑compatible materials circulation.

Seed-Coating Ecosystem Materials for Long-term Preservation and Deterioration Control　

Seed deterioration caused by oxidation, moisture uptake, and microbial contamination is a major barrier to stable crop production. Cellulose nanofiber‑based coatings offer oxygen‑barrier performance, moisture buffering, and gentle adhesion to seed surfaces, while lignin‑derived antioxidants suppress oxidative damage.These ecosystem‑compatible coatings maintain germination rates during extended room‑temperature storage and reduce dependence on cold‑chain logistics. By integrating natural polysaccharide nanoarchitectures with biological protective functions, this technology contributes to resilient agriculture and long‑term ecological materials circulation.

Biodegradable CNF–Lignin Mulching Films and Sprayable Emulsion Mulch for Sustainable Agriculture

Conventional agricultural mulching films generate persistent microplastic waste and disrupt soil ecosystems. We develop fully biodegradable mulching films composed of cellulose nanofibers and lignin, exploiting their natural compatibility, mechanical reinforcement, and UV‑shielding properties.In addition, CNF–lignin emulsions can be spray‑applied to soil surfaces, forming in situ biodegradable mulch layers without plastic residues. These ecosystem‑harmonized materials degrade into benign organic components, support moisture retention and weed suppression, and contribute to carbon‑negative agricultural practices aligned with long‑term ecological circulation. polysaccharide-based nanofibers.

Mayumi Hatakeyama

Assistant Professor, Ph.D.
E-mail: m_hatakeyama@agr.kyushu-u.ac.jp

Laboratory of Bioresources Chemistry,
Department of Agro-Environmental Sciences,
Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, JAPAN
Academic Staff Educational and Research Activities Database of Kyushu University