# Advanced Stem Cell Therapy: 3D‐Bioprinted Brain‐Like Transplants for Alzheimer's Disease‐Like Dementia

## TL;DR

This study introduces a 3D-bioprinted neural patch to improve stem cell therapy for Alzheimer's disease by enhancing cell survival and memory recovery in animal models.

## Contribution

A tri-component bioink-based 3D-bioprinted neural patch is developed to enhance stem cell therapy for Alzheimer's disease.

## Key findings

- The 3D-printed neural patch improved cell retention by 3.41-fold compared to cell suspensions in AD-like rats.
- The patch enhanced neuronal and GABAergic neuron differentiation and restored long-term potentiation to near-healthy levels.
- Behavioral tests showed significant memory improvement in treated AD-like rats.

## Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder that lacks effective treatments and urgently requires innovative therapeutic strategies. Although stem cell therapy has demonstrated efficacy in preclinical and clinical studies, it faces challenges such as low cell survival (<5%) and uncontrolled glial differentiation. This study aims to develop a 3D‐bioprinted neural patch to enhance stem cell therapy for AD. The hypothesis is that a supportive bioengineered microenvironment would improve cell integration and neuronal differentiation, leading to functional recovery. A tri‐component bioink (gelatin/alginate/fibrinogen) is created with tunable printability, biocompatibility, and biodegradation, establishing functional transplantation microenvironments for a 3D‐printed human induced pluripotent stem cell (hiPSC)‐derived neural progenitor cell (NPC) construct as a hippocampal patch. The system (TTBT) maintains NPC survival and promotes neuronal differentiation, neurite development, and calcium signaling in vitro. In AD‐like rats, these constructs improved cell retention (3.41‐fold over suspensions), enhanced neuron (79.21 ± 6.67% vs 65.08 ± 7.14%) and GABAergic neuron (29.85 ± 7.69% vs 15.93 ± 10.33%) differentiation, and restored long‐term potentiation (LTP) to 97.89% ± 19.84% of healthy control levels. Behavioral tests also show memory improvement, particularly in the Morris water maze. This 3D‐printed therapy not only holds potential for enhancing stem cell treatments but also addresses other 3D brain defects.

A tri‐component biomimetic bioink(gelatin/alginate/fibrinogen) is developed to protect cells in critical pathological environments in AD. Using this bioink, a 3D‐printed NPC construct optimized for hippocampal transplantation is provided to improve cell retention and differentiation in an AD‐like model. This approach enhances memory recovery and offers a promising strategy for addressing neurodegenerative diseases through advanced bioengineered therapies.