3D-Printed core-shell tablet for effective oral delivery of AT-MSC secretome in inflammatory bowel disease therapy

Abstract

The complexity of inflammatory bowel disease (IBD) and its pharmacological management has driven research to explore novel treatment options for this condition. Among the emerging therapies, Mesenchymal Stromal Cells (MSCs) have proven to be effective, showing strong immunomodulatory properties. However, the efficiency of direct MSC administration has been questioned due to their short half-life and risk of rejection. As an alternative, MSCs secretome, containing the beneficial paracrine effectors of MSCs, is being explored as a promising cell-free therapeutic tool. However, the oral delivery of this secretome is complex and presents a significant technological challenge. Additionally, the personalization of secretome-based therapies is essential, as it is a costly treatment that requires dose customization for each patient. This study introduces a novel approach for the oral delivery of adipose-tissue derived MSC secretome (AT-S) using 3D-printed core-shell tablets. Remarkably, lyophilized secretome (LpAT-S) was used during the study to improve the manageability and stability of the secretome. The 3D printed system proved to be capable of protecting secretome proteins from gastric degradation, offering an unprecedented possibility for the oral administration of secretome therapies. Overall, this study shows that 3D printing offers a promising, patient-friendly solution for the oral administration of MSC secretome for the first time, aligning with precision medicine goals to provide tailored therapies for IBD.

Introduction

The pharmacological management of Inflammatory Bowel Disease (IBD) is intricate. The main treatments on IBD focus on relieving symptoms and usually involve corticosteroids, biological therapies, or strong immune system suppressors for severe cases. However, resistance to these drugs and their side effects greatly reduce their efficacy [1, 2]. Consequently, research efforts underway to develop novel therapeutic strategies for IBD. Among others, the use of mesenchymal stromal cells (MSCs) for the management of IBD is considered a well-known stated therapeutic approach [3]. The immunomodulatory capacity of MSCs and their ability to modulate the immune response, brand MSCs as a novel therapeutic weapon in IBD [4, 5]. However, the limitations and risks attributed to the administration of MSCs in vivo (i.e. tumorigenicity, thromboembolism, rejection risks etc.) have caused a paradigm shift that seeks the implementation of “cell-free therapies” [6,7,8]. Thus, the paracrine mediators secreted by MSCs, named secretome, have been the novel research target. Notably, the MSCs secretome (MSCs-S) has been linked to induce most of the beneficial effects observed in MSCs therapies, regulating the exaggerated or irregular immune responses seen in IBD by controlling cellular behavior in both innate and adaptive immunity cells [5, 9].

Therefore, in recent years, there has been a vigorous pursuit to control the delivery of secretome within drug delivery devices. Since then, research on secretome administration on IBD in vivo models has been focused on its intraperitoneal or intravenous direct injection or its rectal administration inside of soft vehicles such as hydrogels [10,11,12,13,14]. However, despite being one of the most demanded routes by patients, the oral administration of MSCs-S remains unaddressed. This is likely due to the significant challenges associated with administering MSCs-S orally. As a key point, gastric degradation of the components of MSCs-S is a worrying fact. Thus, ensuring the safe delivery of proteins and growth factors included on it, to the affected areas of the intestine and colon without degradation is of special relevance and highly complicated [5, 14].

Not only does the fragility of the secretome poses challenges, but its complex handling also presents technological limitations for its oral formulation [10]. Firstly, MSCs-S is typically obtained and delivered in liquid form, making it demanding to convert into conventional oral pharmaceutical forms like coated capsules or tablets that can withstand gastric conditions. Noteworthy, accurate dosing of the MSCs-S becomes limited, as large volumes of liquid cannot be easily administered protected, which further constrains the efficient treatment, requiring frequent and multiple dosing. Similarly, drug titration is particularly important when administering MSCs-S, given the lack of precisely established effective doses and the variability in both secretome composition and patient responses. Therefore, rapid titration in patients and dose adjustments within formulations are imperative to optimize treatment outcomes [5, 10,11,, 12, 14, 15].

Considering this framework, it is marked that there is a striking need for the development of novel pharmaceutical dosage forms for the oral administration of secretome. These new formulations must not only shield the secretome from gastric degradation, but also enable rapid formulation in easily modifiable doses, allowing greater flexibility in administration and the production of cost-effective secretome based therapies for IBD [14].

In this context, the development of pharmaceutical forms must not only match but drive the innovation seen in modern therapeutics. To achieve this, cutting-edge manufacturing strategies that provide control and precision in drug delivery systems are essential. A key example of this innovation is the emergence of 3D printing technologies in pharmaceutical manufacturing. These cutting-edge techniques provide unparalleled versatility, allowing for the design of highly specialized dosage forms tailored to specific therapeutic needs, redefining the possibilities of drug delivery [16, 17].

Among the advantages of this technique, 3D printing allows exhaustive control over the production of therapies. It is usually performed in small batches, which allow better analysis and quality control of the formulations [18]. Likewise, small batch production reduces the waste of the excipients and drugs employed, which is of great importance in the case of MSCs-S based therapies in which the pharmaceutical economy is a key player. Furthermore, controlling the shape and size of dosage forms during printing allows greater control over the dosing of therapies and their drug release profile [19]. Thus, by modifying the size and shape of a formulation, its pharmacokinetics can also be tailored. As a main benefit, these modifications can be quickly applied, adjusting the digital model (CAD model) of the printed formulation to the needs of each patient and therapy requirements. Notably, 3D printing of medicines offers the possibility of making complex pharmaceutical dosage forms [20]. The personalized spatial combination of different pharma-inks allows the design of formulations that are difficult to manufacture with usual manufacturing techniques [21]. This allows the creation of compartmentalized pharmaceutical forms that can protect fragile drugs or combine multiple therapies into a single formulation, making treatments simpler for patients [22]. These 3D printing approaches are aligned with the objective of protecting and effectively delivering MSCs-S and take a step further trough precision medicine.

Therefore, in this study, we combined the highly promising therapy of adipose-tissue derived MSCs-S (AT-S) with 3D printing techniques to create formulations suitable for oral delivery. As a key point, to make the AT-MSCs-S manageable and to simplify its formulation, a lyophilized AT-MSCs-S (LpAT-S) powder was employed for the whole development.

We employed the Semisolid Extrusion 3D printing (SSE) technique, which is particularly advantageous as it can be performed without high heating temperatures, thereby safeguarding the integrity of the secretome cytokines and growth factors against denaturation [23, 24].

This way, during the printing process of the core-shell tablets, two types of Pharma-inks were used and positioned in different areas of the formulation: one Pharma-ink based on Eudragit, a polymer commonly used for the coating of gastro-resistant formulations, which was printed as an external shell of the formulation; and another Pharma-ink containing the Lp-AT-S formulated inside of an alginate hydrogel, allowing its controlled dosing through extrusion inside of a protected central compartment. As a result, a core-shell shape AT-MSCs-S loaded tablet was obtained. Throughout the study, we successfully developed innovative Pharma-ink formulations and refined the printing method for advanced 3D-printed core-shell tablets (3DP core-shell tablets). The printed formulations were characterized in terms of shape, size, and internal structure, ensuring the reproducibility and precision of the cutting-edge 3D printing technique. Moreover, the release kinetics of the formulations were established through dissolution studies of fluorescein-loaded systems. We also demonstrated the remarkable ability of these 3DP core-shell tablets to safeguard secretome proteins from the gastric pH environment.

Download the full article as PDF here 3D-Printed core-shell tablet for effective oral delivery of AT-MSC secretome in inflammatory bowel disease therapy

or read it here

Pharma-ink preparation

Pharma-ink for the outer shell part of the formulations was prepared by mixing components with the help of mortar and pestle. Briefly, Eudragit L100-55 (Evonik^®, Darmstadt, Germany) was thoroughly mixed with triethyl citrate (TEC) (Thermo Fisher Scientific, Waltham, MA, USA) and a hydroxyl propyl methylcellulose (HPMC) (Thermo Fisher Scientific, Waltham, MA, USA) 10% dispersion in order to create a white homogeneous paste (Safe shell ink). Accurate composition displayed on Table 1.

Pharma-ink for the inner core part of the formulation was formulated as an alginate hydrogel. Briefly, ultrapure sodium alginate (Novamatrix) was dissolved in distilled water at a concentration of 6% (w/v). For the formulation of fluorescein loaded 3DP core-shell tablets, the alginate solution was mixed using the double syringe method with a fluorescein solution containing 6% fluorescein (w/v) and calcium sulfate (Gibco, Thermo Fisher Scientific, Waltham, MA, USA) at a concentration of 60 mM. Consequently, a 2% (w/v) crosslinked alginate solution was obtained, containing 3% (w/v) fluorescein (Thermo Fisher Scientific, Waltham, MA, USA) (Table 2).

Munoz-Perez, E., Santos-Vizcaino, E., Goyanes, A. et al. 3D-Printed core-shell tablet for effective oral delivery of AT-MSC secretome in inflammatory bowel disease therapy. Drug Deliv. and Transl. Res. (2025). https://doi.org/10.1007/s13346-025-01932-7