Co-Delivery of Valsartan and Metformin from a Thermosensitive Hydrogel-Nanoparticle System Promotes Collagen Production in Proliferating and Senescent Primary Human Dermal Fibroblasts.

Aging negatively impacts skin health, notably through the senescent cell phenotype, which reduces collagen production and leads to thinner, more fragile skin prone to injuries and chronic wounds. We designed a drug delivery system that addresses these age-related issues using a hybrid hydrogel-nanoparticle system that utilizes a poly(δ-valerolactone--lactide)--poly(ethylene-glycol)--poly(δ-valerolactone--lactide) (PVLA-PEG-PVLA) hydrogel. This hydrogel allows for the local, extended release of therapeutics targeting both proliferating and senescent cells.

Supramolecular assembly of polycation/mRNA nanoparticles and in vivo monocyte programming.

Size-dependent phagocytosis is a well-characterized phenomenon in monocytes and macrophages. However, this size effect for preferential gene delivery to these important cell targets has not been fully exploited because commonly adopted stabilization methods for electrostatically complexed nucleic acid nanoparticles, such as PEGylation and charge repulsion, typically arrest the vehicle size below 200 nm. Here, we bridge the technical gap in scalable synthesis of larger submicron gene delivery vehicles by electrostatic self-assembly of charged nanoparticles, facilitated by a polymer structurally designed to modulate internanoparticle Coulombic and van der Waals forces.

Single-Particle Spectroscopic Chromatography Reveals Heterogeneous RNA Loading and Size Correlations in Lipid Nanoparticles.

Lipid nanoparticles (LNP) have emerged as pivotal delivery vehicles for RNA therapeutics. Previous research and development usually assumed that LNPs are homogeneous in population, loading density, and composition. Such perspectives are difficult to examine due to the lack of suitable tools to characterize these physicochemical properties at the single-nanoparticle level.

Formation of ssDNA nanotubes from spherical micelles and their use as a delivery vehicle for chemotherapeutics and senolytics to triple negative breast cancer cells.

With its lack of commonly targeted receptors, triple negative breast cancer (TNBC) is aggressive and difficult to treat. To address this problem, nanotubes self-assembled from single stranded DNA (ssDNA)-amphiphiles were used as a delivery vehicle for doxorubicin (DOX) to target TNBC cells. Since DOX and other standard of care treatments such as radiation have been documented to induce senescence, the ability of the nanotubes to deliver the senolytic ABT-263 was also investigated.

Payload distribution and capacity of mRNA lipid nanoparticles.

Lipid nanoparticles (LNPs) are effective vehicles to deliver mRNA vaccines and therapeutics. It has been challenging to assess mRNA packaging characteristics in LNPs, including payload distribution and capacity, which are critical to understanding structure-property-function relationships for further carrier development. Here, we report a method based on the multi-laser cylindrical illumination confocal spectroscopy (CICS) technique to examine mRNA and lipid contents in LNP formulations at the single-nanoparticle level.

Supramolecular Assembly of Single-Tail ssDNA-Amphiphiles through π-π Interactions.

In this work, we demonstrate the formation of supramolecular architectures from the assembly of single-tail single stranded DNA (ssDNA)-amphiphiles. Short ssDNA sequences of 10 nucleotides that were either unstructured or formed G-quadruplex secondary structures were conjugated to a single 4-(hexadecyloxy)benzamide tail, either directly or through a polycarbon (C) spacer. Conjugation of the ssDNA to the tail did not interfere with the G-quadruplex secondary structure of the ssDNA sequence.

A Localized Enantioselective Catalytic Site on Short DNA Sequences and Their Amphiphiles.

A DNA-based artificial metalloenzyme (ArM) consisting of a copper(II) complex of 4,4'-dimethyl-2,2'-bipyridine (dmbipy-Cu) bound to double-stranded DNA (dsDNA) as short as 8 base pairs with only 2 contiguous central pairs (G for guanine and C for cytosine) catalyzes the highly enantioselective Diels-Alder reaction, Michael addition, and Friedel-Crafts alkylation in water. Molecular simulations indicate that these minimal sequences provide a single site where dmbipy-Cu is groove-bound and able to function as an enantioselective catalyst. Enantioselective preference inverts when d-DNA is replaced with l-DNA.

ssDNA nanotubes for selective targeting of glioblastoma and delivery of doxorubicin for enhanced survival.

Effective treatment of glioblastoma remains a daunting challenge. One of the major hurdles in the development of therapeutics is their inability to cross the blood-brain tumor barrier (BBTB). Local delivery is an alternative approach that can still suffer from toxicity in the absence of target selectivity.

Targeted Liposomes Encapsulating miR-603 Complexes Enhance Radiation Sensitivity of Patient-Derived Glioblastoma Stem-Like Cells.

Despite potential for clinical efficacy, therapeutic delivery of microRNAs (miRNA) remains a major translational barrier. Here, we explore a strategy for miRNA delivery in the treatment of glioblastoma, the most common form of adult brain cancer, that involves complexation of miRNA with polyethylenimine (PEI) and encapsulation in targeted liposomes. miRNA 603 (miR-603) is a master regulatory miRNA that suppresses glioblastoma radiation resistance through down-regulation of insulin-like growth factor 1 (IGF1) signaling.

Effect of an alkyl spacer on the morphology and internalization of MUC1 aptamer-naphthalimide amphiphiles for targeting and imaging triple negative breast cancer cells.

Despite decades of research, there are few targeted treatment options available for triple negative breast cancer (TNBC), leaving chemotherapy, and radiation treatment regimes with poor response and high toxicity. Herein aptamer-amphiphiles were synthesized which selectively bind to the mucin-1 (MUC1) glycoprotein that is overexpressed in TNBC cells. These amphiphiles have a fluorescent tail (1,8-naphthalimide or 4-nitro-1,8-naphthalimide) which enables self-assembly of the amphiphiles and allows for easy visualization without the requirement for further conjugation of a fluorophore.

Thermosensitive and biodegradable hydrogel encapsulating targeted nanoparticles for the sustained co-delivery of gemcitabine and paclitaxel to pancreatic cancer cells.

Pancreatic cancer represents a life threatening disease with rising mortality. Although the synergistic combination of gemcitabine and albumin-bound paclitaxel has proven to enhance the median survival rates as compared to gemcitabine alone, their systemic and repeated co-administration has been associated with serious toxic side effects and poor patient compliance. For this purpose, we designed a thermosensitive and biodegradable hydrogel encapsulating targeted nanoparticles for the local and sustained delivery of gemcitabine (GEM) and paclitaxel (PTX) to pancreatic cancer.

Radiation-induced extracellular vesicle (EV) release of miR-603 promotes IGF1-mediated stem cell state in glioblastomas.

Background: Recurrence after radiation therapy is nearly universal for glioblastomas, the most common form of adult brain cancer. The study aims to define clinically pertinent mechanisms underlying this recurrence.

Methods: microRNA (miRNA) profiling was performed using matched pre- and post-radiation treatment glioblastoma specimens from the same patients.

Design of an Aptamer-Amphiphile for the Detection of β-Lactoglobulin on a Liquid Crystal Interface.

An aptamer-amphiphile was designed that binds to β-lactoglobulin (β-LG), a major allergen from cow's milk. For this work, a 23-nucleotide ssDNA aptamer β-LG-23, capable of forming antiparallel G-quadruplexes was used, and its specificity and binding affinity of 22 ± 2 nM for β-LG were evaluated via enzyme-linked apta-sorbent assay (ELASA). The β-LG-23 aptamer was synthesized as an amphiphile by conjugating it to a C double tail via different spacers, and the effect of the spacers on the binding affinity and secondary structure of the aptamer was investigated.

ssDNA-amphiphile architecture used to control dimensions of DNA nanotubes.

Controlling the dimensions of DNA nanotubes is of great interest as they can be used in different applications ranging from functional elements in nanodevices to carriers for drug delivery. ssDNA-amphiphiles composed of a ssDNA headgroup, a hydrophobic dialkyl tail and a polycarbon spacer between the tail and the headgroup, self-assemble into hollow DNA nanotubes by forming bilayer nanotapes that transition from twisted nanotapes, to helical nanotapes, to nanotubes. The presence of the DNA nanotubes is verified via cryo-TEM and SAXS.

Design and Characterization of a PVLA-PEG-PVLA Thermosensitive and Biodegradable Hydrogel.

A set of poly(δ-valerolactone--d,l-lactide)--poly(ethylene glycol)--poly(δ-valerolactone--d,l-lactide) (PVLA-PEG-PVLA) triblock copolymers was synthesized and the solution properties were characterized using rheology, cryo-TEM, cryo-SEM, SANS, and degradation studies. This polymer self-assembles into a low viscosity fluid with flowerlike spherical micelles in water at room temperature and transforms into a wormlike morphology upon heating, accompanied by gelation. At even higher temperatures syneresis is observed.

Aptamer micelles targeting fractalkine-expressing cancer cells in vitro and in vivo.

In this work we hypothesized that the chemokine fractalkine can serve as a cancer molecular target. We engineered aptamer micelles functionalized with an outer poly(ethylene glycol) (PEG) corona, and investigated the extent and efficacy of using them as a targeting tool against fractalkine-expressing colon adenocarcinoma cells. In vitro cell binding results showed that aptamer micelles bound and internalized to fractalkine-expressing cancer cells with the majority of the micelles found free in the cytoplasm.

Salt Responsive Morphologies of ssDNA-Based Triblock Polyelectrolytes in Semi-Dilute Regime: Effect of Volume Fractions and Polyelectrolyte Length.

A comprehensive study is reported on the effect of salt concentration, polyelectrolyte block length, and polymer concentration on the morphology and structural properties of nanoaggregates self-assembled from BAB single-strand DNA (ssDNA) triblock polynucleotides in which A represents polyelectrolyte blocks and B represents hydrophobic neutral blocks. A morphological phase diagram above the gelation point is developed as a function of solvent ionic strength and polyelectrolyte block length utilizing an implicit solvent ionic strength method for dissipative particle dynamics simulations. As the solvent ionic strength increases, the self-assembled DNA network structures shrinks considerably, leading to a morphological transition from a micellar network to worm-like or hamburger-shape aggregates.

Dual-ligand αβ and αβ integrin targeting enhances gene delivery and selectivity to cancer cells.

Nanoparticles functionalized with cancer-targeting ligands have shown promise but are still limited by off-tumor binding to healthy tissues that express low levels of the molecular target. Targeting two cancer biomarkers using dual-targeted heteromultivalent nanoparticles presents a possible solution to this challenge by requiring overexpression of two separate ligands for localization. In order to guide experimental design, a kinetic model was built to explore how the affinity and valency of dual-ligand liposomes affect the binding and selectivity of delivery to cells with various receptor expression.

The design of peptide-amphiphiles as functional ligands for liposomal anticancer drug and gene delivery.

Liposomal nanomedicine has led to clinically useful cancer therapeutics like Doxil and DaunoXome. In addition, peptide-functionalized liposomes represent an effective drug and gene delivery vehicle with increased cancer cell specificity, enhanced tumor-penetrating ability and high tumor growth inhibition. The goal of this article is to review the recently published literature of the peptide-amphiphiles that were used to functionalize liposomes, to highlight successful designs that improved drug and gene delivery to cancer cells in vitro, and cancer tumors in vivo, and to discuss the current challenges of designing these peptide-decorated liposomes for effective cancer treatment.

Rapid Induction of Cerebral Organoids From Human Induced Pluripotent Stem Cells Using a Chemically Defined Hydrogel and Defined Cell Culture Medium.

Unlabelled: Tissue organoids are a promising technology that may accelerate development of the societal and NIH mandate for precision medicine. Here we describe a robust and simple method for generating cerebral organoids (cOrgs) from human pluripotent stem cells by using a chemically defined hydrogel material and chemically defined culture medium. By using no additional neural induction components, cOrgs appeared on the hydrogel surface within 10-14 days, and under static culture conditions, they attained sizes up to 3 mm in greatest dimension by day 28.

Three-Dimensional Cell Entrapment as a Function of the Weight Percent of Peptide-Amphiphile Hydrogels.

The design of scaffolds which mimic the stiffness, nanofiber structure, and biochemistry of the native extracellular matrix (ECM) has been a major objective for the tissue engineering field. Furthermore, mimicking the innate three-dimensional (3D) environment of the ECM has been shown to significantly altered cellular response compared to that of traditional two-dimensional (2D) culture. We report the development of a self-assembling, fibronectin-mimetic, peptide-amphiphile nanofiber scaffold for 3D cell culture.

A chitosan-hyaluronan-based hydrogel-hydrocolloid supports in vitro culture and differentiation of human mesenchymal stem/stromal cells.

Three-dimensional (3D) cell culture platforms are increasingly utilized due to their ability to more closely mimic the in vivo microenvironment compared to traditional two-dimensional methods. Limitations of currently available 3D materials include lack of cell attachment, long polymerization times, and inclusion of undefined xenobiotics, and cytotoxic cross-linkers. Evaluated here is a unique hydrogel comprised of polyelectrolytic complex (PEC) fibers formed by hyaluronic acid and chitosan (CT).

Divergent Mechanistic Avenues to an Aliphatic Polyesteracetal or Polyester from a Single Cyclic Esteracetal.

The cyclic esteracetal 2-methyl-1,3-dioxane-4-one (MDO) was polymerized in bulk using diethyl zinc as the catalyst and benzyl alcohol as the initiator to yield either the corresponding polyesteracetal (PMDO) or the aliphatic polyester poly(3-hydroxypropionic acid) (PHPA) at low and high catalyst concentrations, respectively. Spectral analysis gave evidence for distinct propagating species in the two catalyst concentration regimes. At low zinc concentrations ring opening by attack of the initiating species at the acetal functionality, yielding a zinc carboxylate, followed by propagation to yield pure PMDO was implicated.