Polymers in Drug Delivery: Shaping the Future of Advanced Therapeutics

Over the past two decades, polymer-based drug delivery systems have evolved from experimental concepts to clinically validated technologies, playing a key role in the development of next-generation therapeutics.

At Curapath, with over 13 years of hands-on expertise, we support biotech and pharmaceutical companies with polymer and lipid-based solutions, from early development to GMP manufacturing. I

In this article, we explore how advanced polymer technologies are enabling breakthroughs in DNA and RNA delivery, targeted LNPs, polymer–drug conjugates, and medical devices, while overcoming key limitations of conventional approaches such as PEGylation and viral vectors.

Next-Generation Transfection Reagents for DNA Delivery and In Vivo CAR-T

Polymers are emerging as powerful alternatives to viral vectors for DNA delivery, enabling safer and more flexible approaches for DNA vaccines and in vivo CAR-T therapies.

At Curapath, we develop high-performance transfection reagents designed to address key challenges in nucleic acid delivery:

High transfection efficiency for DNA
Reduced toxicity compared to conventional systems
Low immune response, enabling multiple dosing
Biodegradable profiles, improving safety in vivo

Our portfolio includes:

STAR polymers: a patented, high-performance targetable transfection reagents for DNA vaccines and in vivo CAR-T
PSar shielding polymers: a shielding strategy that reduces toxicity when combined with transfection reagents and polycations in vivo
Nanoparticle stabilizers like PEG-PGA(currently being manufactured for a Phase III Clinical trial): clinically advanced shielding solutions
Tunable transfection platforms:
- PBAEs
- Modified poly-amino acids (PLys, PLO, PArg)
- PAMAM dendrimers

These systems provide a modular and tunable toolbox for in vivo nucleic acid delivery, enabling optimized performance depending on the therapeutic application.

PEG Alternatives: Overcoming the Limitations of PEGylation

While PEGylation has long been a standard strategy in drug delivery, it presents well-known limitations, including immunogenicity and accelerated blood clearance (ABC effect).

At Curapath, we develop next-generation PEG alternatives designed to improve safety and performance:

Low immune response and reduced reactogenicity
Avoidance of anti-PEG antibody formation
Biodegradability, reducing long-term accumulation
Lower bioaccumulation vs PEG
Prevention of accelerated blood clearance, enabling repeat dosing

These materials are critical for advancing RNA therapeutics, biologics, and nanoparticle-based delivery systems.

Advanced Shielding Lipids for LNPs and Targeted RNA Delivery

Polymers play a central role in the design of lipid nanoparticles (LNPs) for:

mRNA vaccines
Gene therapy
Gene editing
Oncology applications

At Curapath, we offer a broad portfolio of PEG-free shielding lipids and polymers, including:

PSar (polysarcosine) a versatile, tunable, and targetable platform alredy being tested in clinical trials
VitE-PSar our patented derivative with enhanced stability in solution
PGA-diol a patented polymer tehcnology enabling freeze-dried LNP stability, long-term storage, and inhalation delivery
pBetaines a family of patented zwitterionic shielding lipids
POx (polyoxazolines) another tunable and highly adaptable platform

These solutions enable stable, scalable, and clinically translatable LNP formulations, while reducing dependence on PEG.

Targeted LNPs Enabled by CliCr® Click Chemistry

For targeted lipid nanoparticles, Curapath goes beyond conventional formulations.

We develop PSar-based polymers with lipid anchors (C14, C16, C18) that enable precise control over nanoparticle surface properties.

Combined with our proprietary CliCr® click-chemistry platform, these systems allow:

Efficient and scalable ligand conjugation
High functionalization density
Preservation of nanoparticle integrity

This enables advanced strategies for:

Tissue-specific targeting
Extrahepatic delivery (lung, T cells, CNS, bone marrow)

Polymer-Based Solubilization Solutions for Biologics

Polymers also provide powerful solutions for improving the stability and solubility of biologics, including mAbs, proteins, and peptides.

At Curapath, we offer:

Oleyl-PSar our patented alternative to polysorbates
- Improved oxidative stability
- Enhanced solubility performance
- Ideal for next-generation biologics formulations
PSarylation a next-generation polymer–biologic conjugation strategy alternative to PEGylation
- Biodegradable alternative to 40 kDa PEGylation
- Tunable chain length for optimized performance