The direct delivery of functional proteins into the cell cytosol is a key issue for protein therapy, with many current strategies resulting in endosomal entrapment. Protein delivery to the cytosol is challenging due to the high molecular weight and the polarity of therapeutic proteins. Here we review strategies for the delivery of proteins into cells, including cell-penetrating peptides, virus-like particles, supercharged proteins, nanocarriers, polymers, and nanoparticle-stabilized nanocapsules. The advantages and disadvantages of these approaches including cytosolar delivery are compared and contrasted, with promising pathways forward identified.

Engineered nanoparticles (NPs) have broad applications in industry and nanomedicine. When NPs enter the body, interactions with the immune system are unavoidable. The innate immune system, a non-specific first line of defense against potential threats to the host, immediately interacts with introduced NPs and generates complicated immune responses. Depending on their physicochemical properties, NPs can interact with cells and proteins to stimulate or suppress the innate immune response, and similarly activate or avoid the complement system. NPs size, shape, hydrophobicity and surface modification are the main factors that influence the interactions between NPs and the innate immune system. In this review, we will focus on recent reports about the relationship between the physicochemical properties of NPs and their innate immune response, and their applications in immunotherapy.

The delivery of proteins into cells is a potential game changer for a wide array of therapeutic purposes, including cancer therapy, immunomodulation and treatment of inherited diseases. In this review, we present recently developed nanoassemblies for protein delivery that utilize strategies that range from direct assembly, encapsulation and composite formation. We will discuss factors that affect the efficacy of nanoassemblies for delivery from the perspective of both nanoparticles and proteins. Challenges in the field, particularly achieving effective cytosolar protein delivery through endosomal escape or evasion are discussed.

We present here an integrated nanotechnology/biology strategy for cancer immunotherapy that uses arginine nanoparticles (ArgNPs) to deliver CRISPR-Cas9 gene editing machinery into cells to generate SIRP-α knockout macrophages. The NP system efficiently codelivers single guide RNA (sgRNA) and Cas9 protein required for editing to knock out the "don't eat me signal" in macrophages that prevents phagocytosis of cancer cells. Turning off this signal increased the innate phagocytic capabilities of the macrophages by 4-fold. This improved attack and elimination of cancer cells makes this strategy promising for the creation of "weaponized" macrophages for cancer immunotherapy.

Introduction Small interfering RNA (siRNA) is an effective method for regulating the expression of proteins, even “undruggable” ones that are nearly impossible to target through traditional small molecule therapeutics. Delivery to the cell and then to the cytosol is the primary requirement for realization of therapeutic potential of siRNA. Areas covered We summarize recent advances in the design of inorganic nanoparticle with surface functionality and physicochemical properties engineered for siRNA delivery. Specifically, we discuss the main approaches developed so far to load siRNA into/onto NPs, and NP surface chemistry engineered for enhanced intracellular siRNA delivery, endosomal escape, and targeted delivery of siRNA to disease cells and tissues. Expert Opinion Several challenges remain in developing inorganic NPs for efficient and effective siRNA delivery. Getting the material to the chosen site is important, however the greatest hurdle may well be delivery into the cytosol, either through efficient endosomal escape or by direct cytosolic siRNA delivery. Effective delivery at the organismic and cellular level coupled with biocompatible vehicles with low immunogenic response will facilitate the clinical translation of RNAi for the treatment of genetic diseases.

Macrophages are key effectors of host defense and metabolism, making them pro mising targets for transient genetic therapy. Gene edit ing through delivery of the Cas9-ribonucleoprotein (RNP) provides mu ltip le advantages over gene delivery-based strategies for introducing CRISP R machinery to the cell. There are, however, significant physiological, cellular, and intracellular barriers to the effective delivery of the Cas9 protein and guide RNA (sgRNA) that have to date, restricted in vivo Cas9 proteinbased approaches to local/topical delivery applications. Herein we describe a new nanoassembled platform featuring co-engineered nanoparticles and Cas9 protein that has been developed to provide efficient Cas9-sgRNA delivery and conco mitant CRISPR edit ing through systemic tail-vein inject ion into mice, achieving >8% gene editing efficiency in macrophages of the liver and spleen.Received: ((will be filled in by the editorial staff))Revised: ((will be filled in by the editorial staff))

Phenotyping macrophage activation states using an array-based sensor. FRET complex assembly selectively interacts with the macrophage surface, generating a fingerprint for each polarization state that is further used to identify the activation state.

Intracellular bacterial infections are difficult to treat, and in the case of Salmonella and related infections, can be life threatening. Antibiotic treatments for intracellular infections face challenges including cell penetration...