The HPAE platform is being developed to support genetic medicines for rare, untreatable inherited diseases. Our lead programmes focus on a clearly defined molecular target in skin, using two complementary therapeutic directions.
Branca Bunús is developing the HPAE platform as a foundation for genetic medicines. Its modular delivery chemistry is intended to support different therapeutic nucleic acids, cell targets and treatment strategies as research programmes mature.
HPAE-mediated genetic delivery into skin tissue, visually connecting polymer science with therapeutic impact.
HPAE non-viral gene delivery platform
Defined molecular target
Therapeutic genetic cargo
Gene medicine development
The HPAE platform is designed as a flexible delivery system for a range of genetic medicine approaches, including the two lead DEB programmes presented below.
Deliver full-length functional transgenes to restore missing protein expression (BrB202 core programme).
Targeted correction or compensation of disease-causing gene mutations (BrB101 core programme).
Temporary protein expression for acute tissue repair applications.
Non-viral delivery chemistry adaptable to both ex vivo and in vivo therapeutic workflows.
Localised genetic cargo delivery supporting tissue repair and regeneration.
Continuous platform expansion into new therapeutic categories as R&D programmes mature.
Epidermolysis bullosa is a group of rare inherited skin fragility disorders. Dystrophic epidermolysis bullosa, or DEB, is a major subtype caused by mutations in COL7A1.
People living with EB have extremely fragile skin and mucosal tissues, where even minor friction or trauma can lead to painful blisters, wounds and scarring. The severity varies widely: some forms mainly affect the hands and feet, while more severe forms can cause chronic wounds, infection risk, nutritional complications, restricted movement, fibrosis and an increased risk of aggressive skin cancer.
Extremely fragile skin and mucosal tissues can blister after minor friction or trauma.
Blisters can lead to open wounds that may take a long time to heal.
More severe forms can involve infection risk, nutritional complications, restricted movement and fibrosis.
EB is a group of rare inherited skin fragility disorders with a wide range of severity.
A medically accurate cross-section of normal skin versus DEB skin, showing defective COL7A1/type VII collagen anchoring fibrils.
COL7A1 encodes type VII collagen, a key structural protein that forms anchoring fibrils between the epidermis and dermis. When type VII collagen is missing or defective, the skin layers cannot attach properly, leading to blistering below the basement membrane, repeated wound formation, scarring and progressive tissue damage.
COL7A1
→Type VII Collagen
→Anchoring Fibrils
→Dermal–Epidermal Adhesion
COL7A1 mutation
↓Missing / defective Type VII Collagen
↓Weak dermal–epidermal attachment
↓Blistering and repeated wounds
↓Scarring and progressive tissue damage
Epidermis — top layer of skin
Dermis — middle layer
Anchoring fibrils (type VII collagen) — secure the skin layers together
Subcutaneous tissue — deep layer
Type VII collagen forms anchoring fibrils that act like anchors, keeping the top layer of skin firmly attached to the underlying layers. In DEB, these anchors are defective or missing, causing the skin layers to separate easily and blister.
DEB is commonly divided into recessive and dominant inherited forms. The document describes differences in the affected skin level, type VII collagen and clinical features.
RDEB occurs when both copies of the COL7A1 gene are affected. It is described in the source material as generally more severe, with little or no functional type VII collagen.
DDEB occurs when one affected copy of COL7A1 is sufficient to cause disease. It is generally milder than RDEB, with variable severity, and reduced or abnormal but still present type VII collagen.
DEB has a clearly defined molecular cause related to defective or insufficient type VII collagen. This makes it an important candidate for genetic medicine. A successful therapeutic strategy could aim to restore collagen expression and improve skin stability.
Restore type VII collagen expression
Improve dermal–epidermal adhesion
Support wound closure
Reduce repeated cycles of injury and scarring
Improve long-term skin stability
The goal described in the source material is healthier skin with fewer wounds, less scarring and improved quality of life.
Branca Bunús is developing a non-viral gene delivery platform based on advanced polymeric nanoparticles. The technology is designed to package and deliver therapeutic nucleic acids into skin-relevant cells, including keratinocytes and fibroblasts.
Unlike viral vectors, non-viral delivery systems may offer advantages in payload flexibility, repeat administration potential, scalable manufacturing and modular formulation design. These features are particularly relevant where therapeutic strategies may require large genetic payloads, local skin delivery and repeated treatment of chronic or recurrent wounds.
Platform architecture
BrB101 and BrB202 address the same therapeutic target through two different genetic medicine strategies. Both programmes are being developed on Branca Bunús’ HPAE non-viral delivery platform.
Gene editing aims to correct or compensate for disease-causing mutations at the genetic level. A gene editing strategy could offer a more durable correction in treated cells, especially if editing can be achieved in regenerative skin cell populations.
Mechanism
HPAE + Cas9/sgRNA RNP → skin-cell uptake → targeted COL7A1 exon deletion/editing → restored functional expression.
Gene replacement aims to provide cells with a functional version of the COL7A1 genetic instruction, enabling them to produce type VII collagen. The HPAE platform is being designed to deliver large DNA-based payloads and support local expression of therapeutic proteins in skin tissue.
Mechanism
HPAE + full-length COL7A1 plasmid → delivery into dermal/epidermal cells → type VII collagen expression → restoration of anchoring fibrils.
Plasmid with independent intellectual property rights
(Encoding human full-length type VII collagen gene)
While DEB is the flagship translational pipeline asset, the modular HPAE architecture supports broad expansion across oncology, regenerative medicine and immune genetic therapies as R&D programmes mature.
Branca Bunús actively seeks pharma, biotech and academic clinical partners to co-develop HPAE-enabled gene therapy programmes across therapeutic categories. We offer flexible platform licensing, joint development and pre-clinical collaboration frameworks for aligned strategic partners.
