Cells with differentiation potential into mesodermal types are the focus of emerging bone tissue engineering (TE) strategies as an alternative autologous source. When the source of cells is extremely limited or not readily accessible, such as in severe injuries, a tissue biopsy may not yield the required number of viable cells. In line, adipose-derived stromal cells (ASCs) quickly became attractive for bone TE, since they can be easily and repeatably harvested using minimally invasive techniques with low morbidity. Inspired by the multiphenotypic cellular environment of bone, we propose the co-encapsulation of ASCs and osteoblasts (OBs) in self-regulated liquefied and multilayered microcapsules. We explore the unique architecture of such hybrid units to provide a dynamic environment using a simple culture in spinner flasks. Results show that microtissues were successfully obtained inside the proposed microcapsules with an appropriate diffusion of essential molecules for cell survival and signaling. Remarkably, microcapsules cultured in the absence of supplemental osteogenic differentiation factors presented osteopontin immunofluorescence, evidencing that the combined effect of the dynamic environment, and the paracrine signaling between ASCs and OBs may prompt the development of bone-like microtissues. Furthermore, microcapsules cultured under dynamic environment presented an enhanced mineralized matrix and a more organized extracellular matrix ultrastructure compared to static cultures used as control. Altogether, data in this study unveil an effective engineered bioencapsulation strategy for the in vitro production of bone-like microtissues in a more realistic and cost-effective manner. Accordingly, we intend to use the proposed system as hybrid devices implantable by minimally invasive procedures for bone TE applications.

In the primordial cell encapsulation systems, the main goal was to treat endocrine diseases avoiding the action of the immune system. Although lessons afforded by such systems were of outmost importance for the demands of Tissue Engineering and Regenerative Medicine, the paradigm has recently completely changed. If before the most important feature was to mask the encapsulated cells from the immune system, now it is known that the synergetic interplay between immune cells and the engineered niche is responsible by an adequate regenerative process. Combined with such immuno-awareness, novel or non-conventional emerging techniques are being proposed developed the new generation of cell encapsulation systems, namely layer-by-layer, microfluidics, superhydrophobic surfaces, and bioprinting technologies.Alongside with the desire to create more realistic cell encapsulation systems, cell-laden hydrogels are being explored as building blocks for bottom-up strategies, within the concept of modular tissue engineering. The idea is to use the well-established cell friendly environment provided by hydrogels, and create more close-to-native systems owning high heterogeneity, while providing multifunctional and adaptive inputs.

Immuno checkpoint inhibitors have ushered in a new era with respect to the treatment of advanced non-small-cell lung cancer. Many patients are not suitable for treatment with epidermal growth factor receptor tyrosine kinase inhibitors (eg, gefitinib, erlotinib, and afatinib) or with anaplastic lymphoma kinase inhibitors (eg, crizotinib and ceritinib). As a result, anti-PD-1/PD-L1 and CTLA-4 inhibitors may play a novel role in the improvement of outcomes in a metastatic setting. The regulation of immune surveillance, immunoediting, and immunoescape mechanisms may play an interesting role in this regard either alone or in combination with current drugs. Here, we discuss advances in immunotherapy for the treatment of metastatic non-small-cell lung cancer as well as future perspectives within this framework.

tissues. Living tissues are characterized by repetitive functional units, which include combinations of heterogenous cell populations and extracellular matrix (ECM), structured across multiple length scales. In an attempt to mimic such hierarchical, adaptive and complex functionality and spatial organization, the assemble of 3D functional units with defined microarchitectural features was envisaged, in a concept termed modular TE. [1,2] In modular TE approaches, cell-laden hydrogels are being considerably explored as building blocks to create modular tissues with specific geometries and mechanical properties. [3,4] Hydrogels are attractive 3D cell supportive platforms due to their highly hydrated nature, resembling the tissuelike compliance of the native ECM. [5] Cellladen modular units enable the spatial and temporal manipulation of the biomaterials microenvironment, while avoid the invasive procedures inherent to scaffolds implantation into a defect site. Once created, the modular units can be assembled into larger multifunctional tissues, structured in a scale-range manner. Each modular unit can carry distinct cargo, including multiphenotypic cells and biomolecules of interest. The assembly of 3D modular units was already proposed for the fabrication of different tissues, such as cartilage, [6] hepatic, [7] and heart tissues. [8]

From an “over‐engineering” era in which biomaterials played a central role, now it is observed to the emergence of “developmental” tissue engineering (TE) strategies which rely on an integrative cell‐material perspective that paves the way for cell self‐organization. The current challenge is to engineer the microenvironment without hampering the spontaneous collective arrangement ability of cells, while simultaneously providing biochemical, geometrical, and biophysical cues that positively influence tissue healing. These efforts have resulted in the development of low‐material based TE strategies focused on minimizing the amount of biomaterial provided to the living key players of the regenerative process. Through a “minimalist‐engineering” approach, the main idea is to fine‐tune the spatial balance occupied by the inanimate region of the regenerative niche toward maximum actuation of the key living components during the healing process.

The therapeutic effectiveness and biological relevance of technologies based on adherent cells depend on platforms that enable long-term culture in controlled environments. Liquid-core capsules have been suggested as semipermeable moieties with spatial homogeneity due to the high mobility of all components in their core. The lack of cell-adhesive sites in liquid-core structures often hampers their use as platforms for stem cell-based technologies for long-term survival and cell-directed self-organization. Here, the one-step fast formation of robust polymeric capsules formed by interfacial complexation of oppositely charged polyelectrolytes in an all-aqueous environment, compatible with the simultaneous encapsulation of mesenchymal stem/stromal cells (MSCs) and microcarriers, is described. The adhesion of umbilical cord MSCs to polymeric microcarriers enables their aggregation and culture for more than 21 days in capsules prepared either manually by dropwise addition, or by scalable electrohydrodynamic atomization, generating robust and stable capsules. Cell aggregation and secretion overtime can be tailored by providing cells with static or dynamic (bioreactor) environments.

A critical determinant of successful clinical outcomes is the host's response to the biomaterial. Therefore, the prediction of the immunomodulatory bioperformance of biomedical devices following implantation is of utmost importance. Herein, liquefied capsules are proposed as immunomodulatory miniaturized 3D platforms for the high-content combinatorial screening of different polymers that could be used generically in scaffolds. Additionally, the confined and liquefied core of capsules affords a cell-mediated 3D assembly with bioinstructive microplatforms, allowing to study the potential synergistic effect that cells in tissue engineering therapies have on the immunological environment before implantation. As a proof-of-concept, three different polyelectrolytes, ranging in charge density and source, are used. Poly(L-lysine)-, alginate-, and chitosan-ending capsules with or without encapsulated mesenchymal stem/stromal cells (MSCs) are placed on top of a 2D culture of macrophages. Results show that chitosan-ending capsules, as well as the presence of MSCs, favor the balance of macrophage polarization toward a more regenerative profile, through the up-regulation of anti-inflammatory markers, and the release of pro-regenerative cytokines. Overall, the developed system enables the study of the immunomodulatory bioperformance of several polymers in a cost-effective and scalable fashion, while the paracrine signaling between encapsulated cells and the immunological environment can be simultaneously evaluated.

Extraordinary capabilities underlie the potential use of immune cells, particularly macrophages, in bone tissue engineering. Indeed, the depletion of macrophages during bone repair often culminates in disease scenarios. Inspired by the native dynamics between immune and skeletal systems, this work proposes a straightforward in vitro method to bioengineer biomimetic bone niches using biological waste. For that, liquefied and semipermeable reservoirs generated by electrohydrodynamic atomization and layer‐by‐layer techniques are developed to coculture umbilical cord‐derived human cells, namely monocyte‐derived macrophages, mesenchymal‐derived stromal cells (MSCs), and human umbilical vein endothelial cells (HUVECs). Poly(ε‐caprolactone) microparticles are also added to the liquefied core to act as cell carriers. The fabricated microcapsules grant the successful development of viable microtissues, ensuring the high diffusion of bioactive factors. Interestingly, macrophages within the bioengineered microcapsules increase the release of osteocalcin, osteoprotegerin, and vascular endothelial growth factor. The cytokines profile variation indicates macrophages' polarization into a prohealing phenotype. Altogether, the incorporation of macrophages within the fabricated microcapsules allows to recreate an appropriate bone microenvironment for developing new bone mineralized microtissues. The proposed bioencapsulation protocol is a powerful self‐regulated system, which might find great applicability in bone tissue engineering based on bottom‐up approaches or disease modeling.