Polylactic acid (PLA) is the most commonly used biodegradable polymer in clinical applications today. Examples range from drug delivery systems, tissue engineering, temporary and long-term implantable devices; constantly expanding to new fields. This is owed greatly to the polymer's favorable biocompatibility and to its safe degradation products. Once coming in contact with biological media, the polymer begins breaking down, usually by hydrolysis, into lactic acid (LA) or to carbon dioxide and water. These products are metabolized intracellularly or excreted in the urine and breath. Bacterial infection and foreign-body inflammation enhance the breakdown of PLA, through the secretion of enzymes that degrade the polymeric matrix. The biodegradation occurs both on the surface of the polymeric device and inside the polymer body, by diffusion of water between the polymer chains. The median half-life of the polymer is 30 weeks; however, this can be lengthened or shortened to address the clinical needs. Degradation kinetics can be tuned by determining the molecular composition and the physical architecture of the device. Using L-or D-chirality of the LA will greatly slow or lengthen the degradation rates, respectively. Despite the fact that this polymer is more than 150 years old, PLA remains a fertile platform for biomedical innovation and fundamental understanding of how artificial polymers can safely coexist with biological systems.

Artificial intelligence (AI) and nanotechnology are two fields that are instrumental in realizing the goal of precision medicine—tailoring the best treatment for each cancer patient. Recent conversion between these two fields is enabling better patient data acquisition and improved design of nanomaterials for precision cancer medicine. Diagnostic nanomaterials are used to assemble a patient‐specific disease profile, which is then leveraged, through a set of therapeutic nanotechnologies, to improve the treatment outcome. However, high intratumor and interpatient heterogeneities make the rational design of diagnostic and therapeutic platforms, and analysis of their output, extremely difficult. Integration of AI approaches can bridge this gap, using pattern analysis and classification algorithms for improved diagnostic and therapeutic accuracy. Nanomedicine design also benefits from the application of AI, by optimizing material properties according to predicted interactions with the target drug, biological fluids, immune system, vasculature, and cell membranes, all affecting therapeutic efficacy. Here, fundamental concepts in AI are described and the contributions and promise of nanotechnology coupled with AI to the future of precision cancer medicine are reviewed.

Overexpressed extracellular matrix (ECM) in pancreatic ductal adenocarcinoma (PDAC) limits drug penetration into the tumor and is associated with poor prognosis. Here, we demonstrate that a pretreatment based on a proteolytic-enzyme nanoparticle system disassembles the dense PDAC collagen stroma and increases drug penetration into the pancreatic tumor. More specifically, the collagozome, a 100 nm liposome encapsulating collagenase, was rationally designed to protect the collagenase from premature deactivation and prolonged its release rate at the target site. Collagen is the main component of the PDAC stroma, reaching 12.8 ± 2.3% vol in diseased mice pancreases, compared to 1.4 ± 0.4% in healthy mice. Upon intravenous injection of the collagozome, ∼1% of the injected dose reached the pancreas over 8 h, reducing the level of fibrotic tissue to 5.6 ± 0.8%. The collagozome pretreatment allowed increased drug penetration into the pancreas and improved PDAC treatment. PDAC tumors, pretreated with the collagozome followed by paclitaxel micelles, were 87% smaller than tumors pretreated with empty liposomes followed by paclitaxel micelles. Interestingly, degrading the ECM did not increase the number of circulating tumor cells or metastasis. This strategy holds promise for degrading the extracellular stroma in other diseases as well, such as liver fibrosis, enhancing tissue permeability before drug administration.

Gene therapy uses nucleic acids as functional molecules to activate biological treatment for a wide range of diseases, such as cancer 1,2 , cystic fibrosis 3 , heart disease 4 , diabetes 5 , haemophilia and HIV/AIDS 6 . Nucleic acids have been attracting increasing attention owing to the global effort in the human genome elucidation together with recent discoveries such as RNA interference (RNAi) and CRISPR-based genome editing [7][8][9] . Gene therapy uses genetic material to alter the expression of a target gene or to modify the biological properties of living cells for therapeutic needs. In recent years, multiple gene therapy products have been approved by the regulatory agencies for various applications 10 . Perhaps the most relevant example is the authorization of mRNA vaccines to fight the COVID-19 outbreak 11 .Gene therapy can be divided into three main avenues, as detailed in Fig. 1. First is editing mutated genes using CRISPR-Cas technology to cause gain or loss of function 12,13 . Second, upregulating gene expression can be achieved through the insertion of a functional gene copy to be expressed by using molecules such as DNA plasmid (pDNA), minicircle DNA (mcDNA), synthetic mRNA, circular RNA and self-amplifying RNA (saRNA) [14][15][16] . Last is downregulating gene expression using molecules such as small interfering RNA (siRNA), antisense oligonucleotides (ASOs), short hairpin RNA (shRNA) and microRNA (miRNA) 17,18 .Nucleic acids have promising advantages compared with conventional drugs 19 . Unlike the latter, the mechanism of action and high specificity of nucleic acids present a possible therapy route for viral infections, various cancers and undruggable genetic disorders with unmet clinical need. Moreover, theoretically, a single treatment of the genetic payload can achieve a durable and even curative effect 20 . However, delivering nucleic acids to reach their active site inside the cell is challenging owing to their low in vivo stability and rapid host clearance outside cells. Additionally, nucleic acids are poorly permeable through the cellular membrane owing to their negative charge, high molecular weight and hydrophilicity 21 . Nonetheless, few delivery challenges differ between DNA and RNA. For example, the payload and carrier toxicity are of greater concern when delivering RNA molecules usually associated with short-term activity and low retention inside the cell, hence requiring more frequent administration 22 . Alternatively, DNA activity inside the nucleus adds complexity related to low nuclear transport, thus leading to distinguishing design concepts regarding the delivery system compared with RNA molecules 23 . Together with specific challenges relevant to the delivered molecule, the fundamental challenge is to develop tailored systems that can facilitate nucleic acid uptake into target cells. The carrier itself needs to overcome extracellular and intracellular barriers, provide protection from nuclease activity in the bloodstream, enhance and assist with cellular uptake, and promote ...

Development of regulated cellular processes and signaling methods in synthetic cells is essential for their integration with living materials. Light is an attractive tool to achieve this, but the limited penetration depth into tissue of visible light restricts its usability for in-vivo applications. Here, we describe the design and implementation of bioluminescent intercellular and intracellular signaling mechanisms in synthetic cells, dismissing the need for an external light source. First, we engineer light generating SCs with an optimized lipid membrane and internal composition, to maximize luciferase expression levels and enable high-intensity emission. Next, we show these cells’ capacity to trigger bioprocesses in natural cells by initiating asexual sporulation of dark-grown mycelial cells of the fungus Trichoderma atroviride. Finally, we demonstrate regulated transcription and membrane recruitment in synthetic cells using bioluminescent intracellular signaling with self-activating fusion proteins. These functionalities pave the way for deploying synthetic cells as embeddable microscale light sources that are capable of controlling engineered processes inside tissues.