SialoPen: Synthetic Peptide Foldamers That Outperform Classic Cell-Penetrating Peptides

Newly designed SialoPen peptides based on a sialic acid scaffold showed significantly superior cell penetration compared to penetratin and HIV-TAT in both cancer and neuronal cells.

Monreal, I Abrrey et al.·Heliyon·2020·Moderate Evidencein-vitro
RPEP-05006In VitroModerate Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
in-vitro
Evidence
Moderate Evidence
Sample
N=in vitro
Participants
HeLa cancer cells and primary hippocampal neurons treated with SialoPen peptides vs penetratin and TAT

What This Study Found

SialoPen peptides — de novo designed foldamers using a Neu2en scaffold — demonstrated significantly superior cellular uptake compared to classical CPPs penetratin and HIV-TAT in both HeLa and neuronal cells.

Key Numbers

Superior uptake vs penetratin and TAT; confirmed by flow cytometry and confocal; Fmoc SPPS compatible; enhanced biostability

How They Did This

In-vitro study using flow cytometry and live-cell confocal microscopy to compare uptake of SialoPen peptides versus penetratin and HIV-TAT in HeLa cells and primary hippocampal neurons.

Why This Research Matters

Many potential drugs cannot cross cell membranes. SialoPen peptides offer a new delivery platform with better penetration than existing options, potentially unlocking previously inaccessible intracellular drug targets.

The Bigger Picture

SialoPen represents a new generation of synthetic cell-penetrating foldamers that move beyond natural amino acids, offering designers more control over structure, stability, and membrane permeability.

What This Study Doesn't Tell Us

In-vitro study with two cell types only; no in-vivo data; cargo delivery not tested; long-term cytotoxicity not fully characterized.

Questions This Raises

  • ?Can SialoPen peptides deliver therapeutic cargo like siRNA or proteins as effectively as they penetrate alone?
  • ?How do SialoPen peptides perform in vivo — biodistribution, stability, clearance?
  • ?Could the Neu2en scaffold be optimized further for tissue-specific targeting?

Trust & Context

Key Stat:
Outperforms penetratin and TAT SialoPen foldamers showed significantly superior uptake in both HeLa cancer cells and primary hippocampal neurons
Evidence Grade:
Well-characterized in-vitro study with head-to-head comparisons against established CPPs using quantitative flow cytometry and imaging.
Study Age:
Published in 2020; foldamer-based CPPs are an emerging area with growing interest in drug delivery.
Original Title:
SialoPen peptides are new cationic foldamers with remarkable cell permeability.
Published In:
Heliyon, 6(12), e05780 (2020)
Database ID:
RPEP-05006

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

What are SialoPen peptides?

A new class of synthetic cell-penetrating peptides built on a sialic acid scaffold, designed to enter cells more efficiently than existing CPPs like penetratin and HIV-TAT.

Why are foldamer CPPs better than natural ones?

Foldamers use unnatural building blocks that resist degradation, offer tunable secondary structures, and in this case show superior cell penetration compared to peptides made from natural amino acids.

Read More on RethinkPeptides

Cite This Study

RPEP-05006·https://rethinkpeptides.com/research/RPEP-05006

APA

Monreal, I Abrrey; Contreras, Erik M; Wayman, Gary A; Aguilar, Hector C; Saludes, Jonel P. (2020). SialoPen peptides are new cationic foldamers with remarkable cell permeability.. Heliyon, 6(12), e05780. https://doi.org/10.1016/j.heliyon.2020.e05780

MLA

Monreal, I Abrrey, et al. "SialoPen peptides are new cationic foldamers with remarkable cell permeability.." Heliyon, 2020. https://doi.org/10.1016/j.heliyon.2020.e05780

RethinkPeptides

RethinkPeptides Research Database. "SialoPen peptides are new cationic foldamers with remarkable..." RPEP-05006. Retrieved from https://rethinkpeptides.com/research/monreal-2020-sialopen-peptides-are-new

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.