Comparative Biosciences, Inc. (CBI), a leading preclinical Contract Research Organization (CRO), provides a wide range of established and validated dermal pharmacology and efficacy studies in all species in normal and in diseased animals, and with single, multiple or infusion/slow release dose administration with small molecules, biologics, stem cells, nanoparticles and devices. CBI also offers custom studies and custom model development
Delayed Type Hypersensitivity Studies
Delayed type hypersensitivity (DTH), sensitization or maximization studies may be employed for two different purposes to determine if:
- the test article is a dermal sensitizer itself, or
- the test article can suppress an induced delayed type hypersensitivity (DTH) reaction.
CBI offers expertise in the following DTH studies:
- Skin sensitization (maximization) study: Beuhler method
- Skin sensitization (maximization) study: Magnuson-Kligman method
- Delayed type hypersensitivity study: Oxazolone (TH-2 mediated; back skin or ear thickness)
- Delayed type hypersensitivity study: (TH-1 mediated hapten-induced: DNFB, DNCB,TNFB, TNCB, TMA, etc) (back skin or ear thickness)
- Intradermal methylated BSA
- Murine local lymph node assay for assessment of allergic contact dermatitis potential
- Passive cutaneous anaphylaxis
- Chemical i®rritant dermatitis
Dermal Inflammation
In these protocol-driven studies, acute or chronic local dermal inflammation is induced by a variety of means, including for example, administration of mediators or chemoattractants such as fMLP, endotoxin, leukotrienes, cytokines, TNF, or irritants such as turpentine, formalin, or carrageenan, TMA, or intradermal methylated BSA. Test articles are administered and the local anti-inflammatory activity is assessed by various means including wheal size, Draize scores, histopathology, and immunohistochemistry as per protocol. Rodents, rabbits, and guinea pigs are most suitable for these studies, but minipigs are also useful. Studies include acute dermal inflammation studies and chronic dermal inflammation studies.
Dermal Fibrosis (Scleroderma)
In this model of scleroderma or dermal fibrosis, fibrosis is induced by bleomycin administration. Effects of test article on fibrosis formation via clinical signs, histopathology, special stains such as Sirius Red and Trichrome, immunohistochemistry, digital image analysis, and in vitro assays such as Sircol® may be assessed.
Dermal Scarring
The rabbit ear dermal scar model and guinea pig back skin are well characterized models for scar and keloid formation. Effects of test article on scar formation formation via clinical signs, histopathology, special stains such as Sirius Red and Trichrome, immunohistochemistry, digital image analysis, and in vitro assays such as Sircol® may be assessed.
Dermal Burns
In this model, a second degree burn is induced in a focal area of the back in mice. Effects of test article on healing and scar formation are assessed. Effects of test article on burn size and healing via clinical signs, bacteriology, histopathology, special stains such as Sirius Red and Trichrome, immunohistochemistry, digital image analysis, and in vitro assays such as Sircol® may be assessed.
Wound Healing
Wound healing studies may be conducted in normal or diabetic (streptozotocin-induced) animals. In these models (pigs, rabbits, rat), uniform wounds are created surgically and healing assessed. Typical wounds would include full thickness, split thickness, and single cuts. The test article is administered and effects of test article on size, rate and character of healing are determined. Clinical signs, histopathology, immunohistochemistry, histomorphometry/digital image analysis, and tensile strength are powerful tools in assessment of wound healing.
Dermal Delivery Devices
There are many new experimental methods and devices used to deliver a test article to the skin for either local or systemic absorption. The local or topical effects of these devices on the skin as well as the ability of the device to deliver the test article may be determined thru toxicologic, pharmacologic assessments and especially pharmacokinetic assessments. Dermal delivery devices are important in the delivery of drugs for chronic pain and chronic metabolic diseases; any condition in which slow continuous systemic administration of drugs is needed.
Dermal Infection
Botulinum
See Preclinical Contract Botulinum Toxicity Research studies.