Biology subjects

Saltzman, W. M.

Publications and source records attributed to Saltzman, W. M..

10 recordsLinked to original sources

bioRxiv2026

Supramolecular Site-Specific Antibody Drug Conjugates Outperform Cysteine-Conjugated Analogs in Pancreatic Peritoneal Carcinomatosis

Antibody drug conjugates (ADCs) are a burgeoning class of targeted therapies. However, limitations in their synthesis and efficiency of payload delivery restrict their clinical utility. Here we report a supramolecular assembly (SMA) ADC conjugation method, which allows site-specific, uniform drug loading, resulting in an enhanced pharmacokinetic profile and in vivo efficacy. This peptide conjugation strategy relies on spontaneous heterotetrameric coiled-coil formation between a pair of peptides appended on the C-terminus and a drug-loaded complementary pair in aqueous solution. Pairing this SMA conjugation with an antibody that targets the dual-endothlin-1/VEGF signal peptide receptor (DEspR), a pancreatic ductal adenocarcinoma (PDAC) specific receptor, retains antibody binding and plasma stability. When the anti-DEspR monoclonal antibody is conjugated with monomethyl auristatin E (MMAE), the ensuing ADC internalizes following cell surface binding and induces selected cell death in multiple DEspR positive PDAC cell lines. In vivo, the ADC exhibits favorable pharmacokinetics, high tumor specificity, and improves overall survival in a rat orthotopic model of pancreatic peritoneal carcinomatosis, compared to conventional ADC conjugation. A heterotetrameric coiled-coil structure enables the efficient synthesis of a potent ADC, further documenting the versatility of supramolecular scaffolds as key orthogonal building block for site-specific conjugation in biopharmaceutical and biomaterial drug delivery systems. One Sentence SummaryCombining site-specific conjugation of monomethyl auristatin E, via the use of biologically inspired heterotetrameric coiled-coils, with a tumor-selective antibody targeting the dual-endothlin-1/VEGF signal peptide receptor affords a highly effective, ADC, which improves survival in a rat orthotopic model of pancreatic peritoneal carcinomatosis compared to standard cysteine-conjugated analogues with higher drug loading.

bioengineering↗

bioRxiv2025

Endothelial cell MHC molecules are necessary and sufficient to reject 3D-printed human skin grafts in an advanced human immune system mouse

Vascularized skins were 3D-printed using single donor human fibroblasts, pericytes, keratinocytes and endothelial cells (ECs), the latter either unmodified (WT-ECs) or deleted of MHC molecules (KO-ECs). Adult MISTRG6 immunodeficient mice neonatally inoculated with adult human hematopoietic stem cells (HSCs) received printed skin allogeneic to the HSCs and were boosted 3 weeks post-grafting with human peripheral blood mononuclear cells (PBMCs) autologous to the HSCs. HSC inoculation alone produced low levels of circulating human myeloid and lymphoid cells without affecting grafts; PBMC boosting dramatically increased circulating human CD4+ T cells and boosted CD8+ T cells only in mice with WT-EC grafts. These grafts became infiltrated by human macrophages, dendritic cells, CD4+ and CD8+ T cells, and showed evidence of rejection. Shared T cell clones were present in skin and spleen. KO-EC grafts had minimal infiltration of graft or spleen without rejection despite MHC molecule expression on other graft cell types.

immunology↗

bioRxiv2025

Mosaic pattern: lung functional heterogeneity at the alveolus level

Inhaled particles carrying pathogens, pollutants (e.g., microplastics, smoke), therapeutics, and diagnostics are increasingly relevant to public health, yet real-time tracking of aerosol transport in functional alveoli remains challenging. Here, we used the recently developed crystal ribcage to investigate aerosol transport in ex vivo lungs during active ventilation, obtaining the first real-time observations of single aerosol droplet transport and deposition in functional alveoli. We discovered deterministic heterogeneity at both intra- and inter-alveolar levels, with aerosol distribution forming a characteristic "mosaic" pattern in which only specific alveolar clusters received particles. The pattern was consistently formed in vivo during spontaneous breathing and ex vivo using both positive- and negative-pressure ventilation. This pattern was also consistent across a range of aerosols, including small molecules, nanobodies, nanoparticles, microplastics, therapeutics, and pathogens. Additionally, the pattern was observed in murine, porcine, and human lungs, and evolved from birth through aging in mice. The post-deposition stability of the pattern depended on particle type and lung age, lasting from a few minutes for small molecular weight particles to multiple days for cell-binding particles. These alveolar-level heterogeneities may uncover previously unrecognized biological and immunological heterogeneities associated with the mosaic pattern, including its role in postnatal lung development, susceptibility to inhaled airborne hazards such as pollutants and infectious agents, and early pathogenesis and response to inhaled therapeutics in respiratory diseases such as pneumonia, COPD, asthma, and lung cancer.

bioengineering↗

bioRxiv2024

Systemic in utero gene editing as a treatment for cystic fibrosis

In utero gene editing has the potential to modify disease causing genes in multiple developing tissues before birth, possibly allowing for normal organ development, disease improvement, and conceivably, cure. In cystic fibrosis (CF), a disease that arises from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, there are signs of multiorgan disease affecting the function of the respiratory, gastrointestinal, and reproductive systems already present at birth. Thus, treating CF patients early is crucial for preventing or delaying irreversible organ damage. Here we demonstrate proof-of-concept of multiorgan mutation correction in CF using peptide nucleic acids (PNAs) encapsulated in polymeric nanoparticles and delivered systemically in utero. In utero editing was associated with sustained postnatal CFTR activity, at a level similar to that of wild-type mice, in both respiratory and gastrointestinal tissue, without detection of off-target mutations in partially homologous loci. This work suggests that systemic in utero gene editing represents a viable strategy for treating monogenic diseases before birth that impact multiple tissue types.

bioengineering↗

bioRxiv2023

DNA Recognition and Induced Genome Modification by a Hydroxymethyl-γ Tail-Clamp Peptide Nucleic Acid

Peptide nucleic acids (PNA) can target and stimulate recombination reactions in genomic DNA. We have reported that gamma ({gamma})-PNA oligomers possessing the diethylene glycol {gamma}-substituent show improved efficacy over unmodified PNAs in stimulating recombination-induced gene modification. However, this structural modification poses a challenge because of the inherent racemization risk in O-alkylation of the precursory serine side chain. To circumvent this risk and improve {gamma}PNA accessibility, we explore the utility of {gamma}PNA oligomers possessing the hydroxymethyl-{gamma} moiety for gene editing applications. We demonstrate that a {gamma}PNA oligomer possessing the hydroxymethyl modification, despite weaker preorganization, retains the ability to form a hybrid with the double-stranded DNA target of comparable stability and with higher affinity to that of the diethylene glycol-{gamma}PNA. When formulated into poly(lactic-co-glycolic acid) nanoparticles, the hydroxymethyl-{gamma}PNA stimulates higher frequencies ([≥] 1.5-fold) of gene modification than the diethylene glycol {gamma}PNA in mouse bone marrow cells.

genetics↗

bioRxiv2022

Inhalable polymer nanoparticles for versatile mRNA delivery and mucosal vaccination

An inhalable platform for mRNA therapeutics would enable minimally invasive and lung targeted delivery for a host of pulmonary diseases. Development of lung targeted mRNA therapeutics has been limited by poor transfection efficiency and risk of vehicle-induced pathology. Here we report an inhalable polymer-based vehicle for delivery of therapeutic mRNAs to the lung. We optimized biodegradable poly(amine-co-ester) polyplexes for mRNA delivery using end group modifications and polyethylene glycol. Our polyplexes achieved high transfection of mRNA throughout the lung, particularly in epithelial and antigen-presenting cells. We applied this technology to develop a mucosal vaccine for SARS-CoV-2. Intranasal vaccination with spike protein mRNA polyplexes induced potent cellular and humoral adaptive immunity and protected K18-hACE2 mice from lethal viral challenge. One-sentence summaryInhaled polymer nanoparticles (NPs) achieve high mRNA expression in the lung and induce protective immunity against SARS-CoV-2.

bioengineering↗

bioRxiv2022

In utero delivery of miRNA induces epigenetic alterations and corrects pulmonary pathology in congenital diaphragmatic hernia

Structural fetal diseases, such as congenital diaphragmatic hernia (CDH) can be diagnosed prenatally. Neonates with CDH are healthy in utero as gas exchange is managed by the placenta, but impaired lung function results in critical illness from the time a baby takes its first breath. During fetal development, lungs are capable of remarkable growth and the fetus does not yet require lung function for gas exchange. MicroRNA (miR) 200b and its downstream targets in the TGF{beta} pathway are critically involved lung branching morphogenesis. Here we characterize the expression of miR200b and the TGF{beta} pathway at different gestational times using a rat model of CDH. Fetal rats with CDH are deficient in miR200b at gestational day 18. We demonstrate that NPs loaded with miR200b given systemically to fetal rats result in changes in the TGF{beta} pathway; these epigenetic changes improve lung size, lung morphology, and lung vascularization. This is the first demonstration of in utero epigenetic therapy to improve lung growth and development in a pre-clinical model. With refinement, this technique could be applied to fetal cases of CDH or other forms of impaired lung development in a minimally invasive fashion. eTOC SynopsisIn utero treatment with NPs loaded with miR200b improves lung development in a rat model of CDH. miR200b treatment epigenetic changes in the TGF{beta}, leads to larger lungs with more airspace and favorable pulmonary vascular remodeling. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/482144v1_ufig1.gif" ALT="Figure 1"> View larger version (46K): org.highwire.dtl.DTLVardef@3531caorg.highwire.dtl.DTLVardef@57ff5aorg.highwire.dtl.DTLVardef@13d6ee9org.highwire.dtl.DTLVardef@3cb3d8_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioengineering↗

bioRxiv2022

3D bioprinting of an implantable xeno-free vascularized human skin graft

Bioengineered tissues or organs produced using matrix proteins or components derived from xenogeneic sources pose risks of allergic responses, immune rejection, or even autoimmunity. Here, we report successful xeno-free isolation, expansion, and cryopreservation of human endothelial cells, fibroblasts, pericytes and keratinocytes from a single donor. We further demonstrate the bioprinting of a human skin substitute with a dermal layer containing xeno-free cultured human endothelial cells (EC), fibroblasts, and pericytes in a xeno-free bioink containing human collagen type I and fibronectin layered in a biocompatible polyglycolic acid (PGA) mesh and subsequently seeded with xeno-free human keratinocytes to form an epidermal layer. Following implantation of such bilayered skin grafts on the dorsum of immunodeficient mice, keratinocytes form a mature stratified epidermis with rete ridge-like structures. The ECs and pericytes form human EC-lined perfused microvessels within 2 weeks after implantation, preventing graft necrosis, and eliciting further perfusion of the graft by angiogenic host microvessels. In summary, we describe the fabrication of a bioprinted vascularized bilayered skin substitute under completely xeno-free culture conditions demonstrating feasibility of a xeno-free approach to complex tissue engineering.

bioengineering↗

bioRxiv2022

Anti-seed PNAs targeting multiple oncomiRs for brain tumor therapy

Glioblastoma (GBM) is one of the most lethal malignancies in the United States with poor survival and high recurrence rates, suggesting the need for approaches targeting the most important molecular drivers of tumor growth. Here, we aimed to simultaneously target oncomiRs 10b and 21, which have been reported to drive the aggressive growth and invasiveness of GBM. We designed short (8-mer bases) gamma-({gamma})-modified peptide nucleic acids (s{gamma}PNAs), which target the seed region of oncomiRs 10b and 21 with high affinity. We entrapped these anti-miR s{gamma}PNAs in nanoparticles (NPs) formed from a block copolymer of poly(lactic acid) and hyperbranched polyglycerol (PLA-HPG); the NPs were also functionalized with aldehydes to produce bioadhesive NPs. We have previously shown that these bioadhesive NPs (BNPs) produce superior transfection efficiency, with a tropism for tumor cells. The s{gamma}PNA BNPs showed superior anti-miR efficacy in comparison to the regular full length PNA BNPs in vitro. When combined with temozolomide, s{gamma}PNA BNPs administered via convention-enhanced delivery (CED) inhibited the growth of intracranial tumors and significantly improved the survival of animals (>120 days). RNA sequencing analysis revealed the role of vascular endothelial growth factor A (VEGFA) and integrin beta 8 (ITGB8), direct targets of both miR-10b and miR-21, in mediating the tumor growth. Hence, we established that BNPs loaded with anti-seed s{gamma}PNAs targeting multiple oncomiRs is a promising approach to improve the treatment of GBM, with a potential to personalize treatment based on tumor specific oncomiRs. SummaryO_ST_ABSTargeting oncomiRs 21 and 10b to improve GBM survivalC_ST_ABSGlioblastoma (GBM) is an aggressive malignant disorder with high recurrence rates and poor survival. Here, we aimed to simultaneously inhibit two aberrant oncomiRs--miR 21 and miR 10b--which have been previously associated with GBM invasiveness and progression. We synthesized short, gamma-modified peptide nucleic acids (s{gamma}PNA) targeted to the miR seed regions and loaded the s{gamma}PNAs into bioadhesive nanoparticles (BNPs). When the s{gamma}PNA-BNPs were added to cultured tumor cells, we observed significant reduction of target oncomiRs and increase of apoptosis in vitro. When delivered in vivo by convection-enhanced delivery, s{gamma}PNA BNPs dramatically increased the survival in two orthotopic (intracranial) mouse models of GBM. Moreover, the combination of s{gamma}PNA BNPs with temozolomide (TMZ) increased the survival of mice with GBM beyond the planned endpoint (120 days) with significant improvements in histopathology. The proposed strategy of s{gamma}PNA BNP with TMZ provides an alternative, promising approach for treatment of GBM.

cancer biology↗

bioRxiv2022

In vivo correction of cystic fibrosis mediated by PNA nanoparticles

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. We sought to correct the multiple organ dysfunction of the F508del CF-causing mutation using systemic delivery of peptide nucleic acid gene editing technology mediated by biocompatible polymeric nanoparticles. We confirmed phenotypic and genotypic modification in vitro in primary nasal epithelial cells from F508del mice grown at air-liquid interface and in vivo in F508del mice following intravenous delivery. In vivo treatment resulted in a partial gain of CFTR function in epithelia as measured by in situ potential differences and Ussing chamber assays and correction of CFTR in both airway and GI tissues with no off-target effects above background. This is the first report of systemic gene editing for CF. Our data suggest that systemic delivery of PNA NPs designed to correct CF-causing mutations is a viable option to ameliorate the disease in multiple affected organs.

bioengineering↗