How 3D Printing and Polysaccharides are Building “Active” Cancer Immunotherapy Patches

In late December 2025, a research group in China published a comprehensive review on an emerging material in the microneedle landscape: natural polysaccharides. While these “complex carbs” are derived from simple plant, animal, and microbial sources, their potential for 3D fabrication is anything but basic. Unlike traditional silicon or synthetic polymer microneedles that act as passive “envelopes,” polysaccharide microneedles (PMNs) function as active therapeutic platforms. Because they are inherently biocompatible, biodegradable, and capable of priming the immune system, they are being reimagined as a tool for cancer immunotherapy. The review, published in Glycoscience & Therapy, in part explored how micro molding and 3D printing are being used to fabricate such tools. After explaining why polysaccharides are a desirable material, we’ll get into how AM technologies specifically are unlocking their potential.

Why Polysaccharide Microneedles?

Natural polysaccharides offer a “living” alternative to the inert or brittle materials traditionally used in 3D printing. While inorganic substances like silicon and glass carry a high risk of fracturing and leaving hazardous shards in the skin, polysaccharides are bioresorbable, safely dissolving into harmless metabolites after delivery. More importantly for oncology, these complex carbohydrates are bioactive. They act as natural adjuvants that “prime” the immune system to recognize tumor cells more effectively.

3D Printing: Addressing Polysaccharides’ Rheology

For engineers, the challenge with natural polysaccharides is their rheology and mechanical properties. While they are biological powerhouses, they often lack the structural integrity required to penetrate the skin’s tough outer barrier without buckling. To bridge this gap, the research group identified three fabrication strategies that leverage 3D printing’s precision to reinforce these soft materials.

1. Indirect Fabrication

The most common hurdle is that many polysaccharides are too viscous or structurally “soft” for high-resolution direct printing via stereolithography (SLA). To solve this, researchers use indirect additive manufacturing. In this workflow, high-resolution digital light processing (DLP) or SLA is used to print a “master” microneedle array with sub-micron accuracy. This master serves as a template to create a negative silicone mold.